National Assessment of Shoreline Change— 

Historical Shoreline Change Along the North Coast of 

Alaska, U.S.-Canadian Border to Icy Cape

U.S. Department of the Interior

U.S. Geological Survey

Open-File Report 2015–1048
Cover: Oblique aerial photograph at Flaxman Island showing tapped and untapped 

thermokarst lakes, caribou tracks, narrow beaches, and bluff failures along the coast.

Image taken August 9, 2006.
National Assessment of Shoreline Change—

Historical Shoreline Change along the North Coast of 

Alaska, U.S.–Canadian Border to Icy Cape

By Ann E. Gibbs and Bruce M. Richmond

Open–File Report 2015–1048

U.S. Department of the Interior

U.S. Geological Survey
U.S. Department of the Interior

SALLY JEWELL, Secretary

U.S. Geological Survey

Suzette M. Kimball, Acting Director

U.S. Geological Survey, Reston, Virginia: 2015

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Suggested citation:

Gibbs, A.E., and Richmond, B.M., 2015, National assessment of shoreline change—Historical shoreline change along 

the north coast of Alaska, U.S.–Canadian border to Icy Cape: U.S. Geological Survey Open-File Report 2015–1048, 

96 p., http://dx.doi.org/10.3133/ofr20151048.

ISSN 2331-1258 (online)
iii

Contents

Executive Summary.......................................................................................................................................1

Introduction.....................................................................................................................................................3

U.S. Geological Survey National Assessment of Shoreline Change............................................3

The Role of State and Federal Governments ...................................................................................4

Previous National and Northern Alaska Shoreline Assessments.........................................................5

Geology and Geomorphology of the North Coast of Alaska...................................................................6

Lands of Unique Importance...............................................................................................................6

Geologic and Tectonic Setting............................................................................................................7

The Late Quaternary....................................................................................................................7

Surficial Geology and Geomorphology .............................................................................................8

Coastal Environments .................................................................................................................8

Coastal Bluffs ......................................................................................................................8

Beaches and Barrier Spits................................................................................................9

Barrier Islands.....................................................................................................................9

Coastal Lagoons..................................................................................................................9

Wetlands ............................................................................................................................10

Deltas ................................................................................................................................10

Permafrost .........................................................................................................................10

Thermokarst.......................................................................................................................10

Dunes ................................................................................................................................10

Methods of Analyzing Shoreline Change ................................................................................................11

Compilation of Historical Shorelines ...............................................................................................11

1940s-Era Shorelines.................................................................................................................12

2000s-Era Shorelines.................................................................................................................13

Estimation of Shoreline Position Uncertainty ................................................................................14

Calculation of Shoreline Change Rates ..........................................................................................16

Estimation of Shoreline Change Rate Uncertainty at Individual Transects .....................16

Estimation of Regionally Averaged Shoreline Change Rate Uncertainty.........................16

Historical Shoreline Change Analysis......................................................................................................17

(1) U.S.-Canadian Border to Jago River..........................................................................................25

Introduction.................................................................................................................................25

Sheltered Mainland-Lagoon Shoreline Change ...................................................................26

Exposed Open-Ocean Shoreline Change ..............................................................................26

(2) Jago River to Staines River .........................................................................................................31

Introduction.................................................................................................................................31

Sheltered Mainland-Lagoon Shoreline Change ...................................................................33

Jago River Delta to Okpilak-Hulahula River Delta.......................................................33

Okpilak-Hulahula River Delta to Sadlerochit River .....................................................33

Sadlerochit River to Konganevik Point..........................................................................34

Konganevik Point to Staines River.................................................................................34

Exposed Open-Ocean Shoreline Change ..............................................................................35

Jago River Delta to Okpilak-Hulahula River Delta.......................................................35
iv

Contents—Continued

Okpilak-Hulahula River Delta to Sadlerochit River .....................................................35

Sadlerochit River to Konganevik Point..........................................................................35

Konganevik Point to the Staines River..........................................................................36

(3) Staines River to Sagavanirktok River.........................................................................................38

Introduction.................................................................................................................................38

Sheltered Mainland-Lagoon Shoreline Change ...................................................................41

Exposed Open-Ocean Shoreline Change ..............................................................................41

Flaxman Island ..................................................................................................................44

Maguire Islands ................................................................................................................45

Stockton Islands ...............................................................................................................45

McClure Islands................................................................................................................45

Tigvariak Islands ...............................................................................................................45

(4) Sagavanirktok River to Colville River.........................................................................................47

Introduction.................................................................................................................................47

Sheltered Mainland-Lagoon Shoreline Change ...................................................................49

Heald Point to Point McIntyre (Prudhoe Bay)..............................................................49

Point McIntyre to Kuparuk River Delta .........................................................................49

Kuparuk River Delta to Milne Point................................................................................49

Milne Point to Oliktok Point.............................................................................................51

Oliktok Point to Colville River Delta................................................................................51

Exposed Open-Ocean Shoreline Change ..............................................................................52

Cross Island .......................................................................................................................52

Midway Islands.................................................................................................................53

Stump, Egg, and Eastern Long Islands..........................................................................53

West Long Island to Leavitt Island.................................................................................54

Spy Islands.........................................................................................................................54

Thetis Island ......................................................................................................................54

(5) Colville River to Cape Halkett ......................................................................................................56

Introduction.................................................................................................................................56

Exposed Open-Ocean Shoreline Change ..............................................................................57

Tingmeachsiovik River to Kalikpik River .......................................................................57

Kalikpik River to Atigaru Point ........................................................................................57

Atigaru Point to Kogru River ...........................................................................................57

Kogru River to Cape Halkett............................................................................................60

(6) Cape Halkett to Drew Point .........................................................................................................61

Introduction.................................................................................................................................61

Sheltered Coast Shoreline Change.........................................................................................63

Exposed Open-Ocean Shoreline Change ..............................................................................65

(7) Drew Point to Dease Inlet............................................................................................................66

Introduction.................................................................................................................................66

 Sheltered Mainland-Lagoon Shoreline Change ..................................................................68

Sinclair River to Tangent Point .......................................................................................68

Tangent Point to Black Head...........................................................................................68

Exposed Open-Ocean Shoreline Change ..............................................................................69

Drew Point to Ikpikpuk River Delta ................................................................................69

Cape Simpson to Kulgurak Island ..................................................................................70
v

Figures

 1. Shaded relief index map of the north coast of Alaska showing study area and key 

geographic locations ...................................................................................................................4

 2. Relief map showing three major physiographic provinces of northern Alaska ................7

 3. Map showing coastline type and generalized surficial geology of study area, 

north coast of Alaska ...................................................................................................................8

 4. Index map of the north coast of Alaska showing shoreline data sources used in this 

study and their approximate extents.......................................................................................12

 5. Index map of the north coast of Alaska showing the 10 analysis regions used in this 

study..............................................................................................................................................17

 6. Index map of Regions 1, 2, and 3 showing geographic names discussed in the 

report ............................................................................................................................................18

 7. Index map of Regions 4, 5 and 6 showing geographic names discussed in the 

report ............................................................................................................................................19

 8. Index map of Regions 7 and 8 showing geographic names discussed in the report .....20

 9. Index map of Regions 9 and 10 showing geographic names discussed in the report ...21

 10. Map showing color-coded shoreline types within Region 1, U.S.-Canadian border to

Jago River, north coast of Alaska ............................................................................................25

 11. Aerial photograph characteristic of Region 1, U.S.-Canadian border to Jago River, 

north coast of Alaska, near Siku Entrance and Egaksrak Lagoon where a narrow 

lagoon separates a low-lying, unvegetated barrier island along the open coast from 

the low-lying, tundra coast on the landward side of the lagoon........................................26

Contents—Continued

(8) Dease Inlet to Barrow ..................................................................................................................71

Introduction.................................................................................................................................71

Sheltered Mainland-Lagoon Shoreline Change ...................................................................72

Exposed Open-Ocean Shoreline Change ..............................................................................74

Igalik Island to Sanigaruak Pass....................................................................................75

Sanigaruak Pass to Ekilukruak Entrance......................................................................75

Ekilukruak Entrance to Eluitkak Pass ............................................................................77

Plover Point to Barrow Peninsula..................................................................................78

(9) Barrow to Peard Bay ....................................................................................................................78

Introduction.................................................................................................................................78

Exposed Open-Ocean Shoreline Change ..............................................................................79

(10) Peard Bay to Icy Cape................................................................................................................82

Introduction.................................................................................................................................82

Sheltered Mainland-Lagoon Shoreline Change ...................................................................83

Peard Bay...........................................................................................................................83

Kilmantavi to Icy Cape .....................................................................................................83

Exposed Open-Ocean Shoreline Change ..............................................................................87

Discussion and Additional Considerations..............................................................................................90

Influence of Human Activities ..........................................................................................................92

Planned Updates.................................................................................................................................92

Acknowledgments.......................................................................................................................................92

References Cited..........................................................................................................................................92
vi

 12. Map showing color-coded shoreline change rates in Region 1, U.S.-Canadian border 

to Jago River, north coast of Alaska........................................................................................27

 13. Graph of shoreline change rates for sheltered mainland-lagoon coast of Region 1, 

U.S.-Canadian border to Jago River, north coast of Alaska................................................28

 14. Graph of shoreline change rates for exposed open-ocean coast of Region 1, 

U.S.-Canadian border to Jago River, north coast of Alaska................................................29

 15. Maps showing examples of shoreline change at Oruktalik Lagoon, north coast of 

Alaska, where barrier migration resulted in the closure of Oruktalik Entrance 

between 1947 and 2003..............................................................................................................30

 16. Map showing color-coded shoreline types within Region 2, Jago River to Staines 

River, north coast of Alaska ......................................................................................................31

 17. Aerial photographs showing typical examples of the coast of Region 2, Jago River 

to Staines River, north coast of Alaska ...................................................................................32

 18. Map showing color-coded shoreline change rates in Region 2, U.S.-Canadian border 

to Jago River, north coast of Alaska........................................................................................33

 19. Graph of shoreline change rates for sheltered mainland-lagoon coast of Region 2, 

Jago River to Staines River, north coast of Alaska...............................................................34

 20. Graph of shoreline change rates for the exposed open-ocean coast of Region 2, 

Jago River to Staines River, north coast of Alaska...............................................................36

 21. Map showing color-coded shoreline change rates for Barter Island and adjacent 

areas, Region 2, Jago River to Staines River, north coast of Alaska .................................37

 22. Map of 1947 T-sheet data overlain on 2003 QuickBirdTM satellite image showing 

barrier islands offshore of Okpilak-Hulahula River Delta and Sadlerochit River in 

Region 2, Jago River to Staines River, north coast of Alaska .............................................37

 23. Map showing color-coded shoreline types within Region 3, Staines River to 

Sagavanirktok River, north coast of Alaska. ..........................................................................38

 24. Aerial photographs showing typical examples of the coast of Region 3, Staines River 

to Sagavanirktok River, north coast of Alaska.......................................................................39

 25. Map showing color-coded shoreline change rates in Region 3, Staines River to 

Sagavanirktok River, north coast of Alaska ...........................................................................40

 26. Graph of shoreline change rates for the sheltered mainland-lagoon coast of 

Region 3, Staines River to Sagavanirktok River, north coast of Alaska.............................41

 27. Maps showing examples of shoreline change along mainland coast of Region 3, 

Staines River to Sagavanirktok River, north coast of Alaska ..............................................42

 28. Graph of shoreline change rates for exposed open-ocean coast of Region 3, 

Staines River to Sagavanirktok River, north coast of Alaska ..............................................43

 29. Detailed maps of barrier islands in Region 3, Staines River to Sagavanirktok River, 

north coast of Alaska .................................................................................................................44

 30. Map showing shoreline change rates for the Tigvariak Islands, Region 3, 

Staines River to Sagavanirktok River, north coast of Alaska ..............................................46

 31. Map showing color-coded shoreline types within Region 4, Sagavanirktok River to 

Colville River, north coast of Alaska ........................................................................................47

 32. Map showing color-coded shoreline change rates in Region 4, Sagavanirktok River 

to Colville River, north coast of Alaska....................................................................................48

 33. Graph of shoreline change rates for sheltered mainland-lagoon coast of Region 4, 

Sagavanirktok River to the Colville River, north coast of Alaska........................................50

 34. Aerial photographs showing typical examples of mainland coast of Region 4, 

Sagavanirktok River to Colville River, north coast of Alaska...............................................51

 35. Graph of shoreline change rates for exposed open-ocean coast of Region 4, 

Sagavanirktok River to Colville River, north coast of Alaska...............................................52

Figures—Continued
vii

 36. Aerial photographs showing typical examples of the barrier island coast of Region 4, 

Sagavanirktok River to Colville River, north coast of Alaska...............................................53

 37. Detailed maps showing shoreline change to the barrier island chain in Region 4, 

Sagavanirktok River to Colville River, north coast of Alaska...............................................55

 38. Map showing color-coded shoreline types within Region 5, Colville River to 

Cape Halkett, north coast of Alaska ........................................................................................56

 39. Coastal elevation map derived from Interferometric Synthetic Aperture Radar data

 for parts of Regions 5–9, Colville River to Icy Cape, north coast of Alaska.....................57

 40. Map showing the color-coded shoreline change rates in Region 5, Colville River to 

Cape Halkett, north coast of Alaska ........................................................................................58

 41. Graph of shoreline change rates for exposed open-ocean coast of Region 5, 

Colville River to Cape Halkett, north coast of Alaska ...........................................................59

 42. Aerial photographs showing typical examples of the coast of Region 5, Colville River

 to Cape Halkett, north coast of Alaska...................................................................................60

 43. Map showing color-coded shoreline types within Region 6, Cape Halkett to Drew 

Point, north coast of Alaska......................................................................................................61

 44. Aerial photographs showing typical examples of coast of Region 6, Cape Halkett to 

Drew Point, northern Alaska.....................................................................................................62

 45. Map showing the color-coded shoreline change rates in Region 6, Cape Halkett to 

Drew Point, north coast of Alaska ...........................................................................................63

 46. Maps and graphs showing shoreline change rates for Pogik Bay and neighboring 

coastline within Region 6, Cape Halkett to Drew Point, northern Alaska.........................64

 47. Graph of shoreline change rates for exposed open-ocean coast of Region 6, 

Cape Halkett to Drew Point, north coast of Alaska...............................................................65

 48. Map showing color-coded shoreline change rates in Region 7, Drew Point to 

Dease Inlet, north coast of Alaska...........................................................................................66

 49. Aerial photographs showing typical examples of coast of Region 7, Drew Point to 

Dease Inlet, north coast of Alaska...........................................................................................67

 50. Map showing color-coded shoreline change rates in Region 7, Drew Point to 

Dease Inlet, north coast of Alaska...........................................................................................68

 51. Graph of shoreline change rates for sheltered mainland-lagoon coast of Region 7, 

Sinclair River to Black Head, north coast of Alaska.............................................................69

 52. Graph of shoreline change rates for exposed open-ocean coast of Region 7, 

Drew Point to Kulgurak Island, north coast of Alaska..........................................................70

 53. Map showing color-coded shoreline types within Region 8, Dease Inlet to Barrow, 

north coast of Alaska. ................................................................................................................71

 54. Aerial photographs showing typical examples of mainland coast of Region 8, 

Dease Inlet to Barrow, northern Alaska .................................................................................72

 55. Aerial photographs showing typical examples of barrier coast of Region 8, 

Dease Inlet to Barrow, northern Alaska .................................................................................73

 56. Map showing color-coded shoreline change rates in Region 8, Dease Inlet to 

Barrow, north coast of Alaska..................................................................................................74

 57. Graph of shoreline change rates for sheltered mainland-lagoon coast of Region 8,

Dease Inlet to Barrow, north coast of Alaska........................................................................75

 58. Graph of shoreline change rates for exposed open-ocean coast of Region 8, 

Dease Inlet to Barrow, northern Alaska .................................................................................76

 59. Detailed map showing shorelines of Plover Islands fronting Elson Lagoon for time 

periods 1947, 2005, and 2010 .....................................................................................................77

 60. Map showing color-coded shoreline types within Region 9, Barrow to Peard Bay, 

north coast of Alaska. ................................................................................................................78

Figures—Continued
viii

 61. Aerial photographs showing typical examples of coast of Region 9, Barrow to 

Peard Bay, north coast of Alaska.............................................................................................79

 62. Map showing color-coded shoreline change rates in Region 9, Barrow to Peard Bay, 

north coast of Alaska .................................................................................................................80

 63. Graph of shoreline change rates for exposed open-ocean coast of Region 9, Barrow

 to Peard Bay, north coast of Alaska.......................................................................................81

 64. Map showing color-coded shoreline types within Region 10, Peard Bay to Icy Cape, 

north coast of Alaska. ................................................................................................................82

 65. Map showing historical shorelines plotted over A, 2010 satellite image, and B, 

2011 Digital Elevation Model of Icy of the lagoon coast near Icy Cape ............................83

 66. Map showing color-coded shoreline change rates in Region 10, Peard Bay to Icy 

Cape, north coast of Alaska......................................................................................................84

 67. Graph of shoreline change rates for sheltered mainland-lagoon coast of Region 10, 

Peard Bay to Icy Cape, north coast of Alaska.......................................................................85

 68. Graph of shoreline change rates for exposed open-ocean coast of Region 10, 

Peard Bay to Icy Cape, north coast of Alaska.......................................................................86

 69. Aerial photographs showing typical examples of sheltered mainland-lagoon coast of 

Region 10, Peard Bay to Icy Cape, north coast of Alaska....................................................87

 70. Aerial photographs showing typical examples of exposed open-coast shore types of 

Region 10, Peard Bay to Icy Cape, north coast of Alaska....................................................88

 71. Detailed maps showing four examples of shoreline change patterns on barrier 

islands and spits within Region 10, Peard Bay to Icy Cape, north coast of Alaska, 

between 1947/49 and 2010/11 ...................................................................................................89

 72. Map showing color-coded shoreline change rates for the north coast of Alaska, 

U.S.-Canadian border to Icy Cape and the boundaries of the ten analysis areas 

discussed in this report .............................................................................................................90

Tables

 1. Providers and original sources of historical shoreline data for the north coast of 

Alaska ...........................................................................................................................................11

 2. Shorelines used to calculate change rates for the north coast of Alaska by coastal 

segment........................................................................................................................................13

 3. Measurement uncertainties associated with all datasets..................................................15

 4. Water level deviation from Mean High Water (MHW) and associated change in 

shoreline position .......................................................................................................................15

 5. Shoreline change rates for north coast of Alaska regions and subregions ....................22

 6. Total barrier island area in Region 3, Staines River to Sagavanirktok River, north 

coast of Alaska, for each era and total change during analysis period, in square 

meters...........................................................................................................................................42

 7. Total barrier island area in Region 4, Sagavanirktok River to Colville River, north 

coast of Alaska, for each era and total change during analysis period, in square 

meters...........................................................................................................................................49

 8. Total barrier island area in Region 8, Dease Inlet to Barrow, north coast of Alaska, 

for each era and total change during analysis period, in square meters .........................76

 9. Summary of shoreline change rates for study area and each region relative to 

shoreline type..............................................................................................................................91

Figures—Continued
ix

Multiply By To obtain

Length

centimeter (cm) 0.3937 inch (in.)

meter (m) 3.281 foot (ft) 

meter (m) 1.094 yard (yd) 

kilometer (km) 0.6214 mile (mi)

kilometer (km) 0.5400 mile, nautical (nmi) 

Area

square meter (m2) 10.76 square foot (ft2)

square kilometer (km2) 0.3861 square mile (mi2)

Erosion and accretion rate

meter per year (m/yr) 3.281 foot per year (ft/yr) 

Coastal land loss rate

square kilometer per year (km2/yr) 0.3861 square mile per year (mi2/yr) 

Conversion Factors

[International System of Units to Inch/Pounds]

Datums

All positional measurements were made in the Universal Transverse Mercator (UTM) coordinate 

system on the North American Datum of 1983 (NAD 83). Data provided with this report were 

reprojected to the Geographic Coordinate System (GCS, latitude and longitude) on the WGS 84 

datum using the WGS_1984_(ITRF00)_To_NAD_1983 transformation in ESRI ArcGISTM v. 10.1.

Elevation, as used in this report, refers to distance above sea level.

Executive Summary

Beach erosion is a persistent problem along most openocean shores of the United States. Along the Arctic coast of 

Alaska, coastal erosion is widespread, may be accelerating, 

and is threatening defense and energy-related infrastructure, 

coastal habitats, and Native communities. As coastal 

populations continue to expand and infrastructure and habitat 

are increasingly threatened by erosion, there is increased 

demand for accurate information regarding past and present 

trends and rates of shoreline movement. There also is a need 

for a comprehensive analysis of shoreline change with metrics 

that are consistent from one coastal region to another. To meet 

these national needs, the U.S. Geological Survey is conducting 

an analysis of historical shoreline changes along the open-ocean 

sandy shores of the conterminous United States and parts of 

Hawaii, Alaska, and the Great Lakes. One purpose of this work 

is to develop standard, repeatable methods for mapping and 

analyzing shoreline change so that periodic, systematic, and 

internally consistent updates regarding coastal erosion and land 

loss can be made nationally.

This report on shoreline change along the north coast of 

Alaska, between the U.S.-Canadian border and Icy Cape, is one 

in a series of regionally focused reports on historical shoreline 

change. Previous investigations include analyses and descriptive 

reports for the coasts of the U.S. Gulf of Mexico, the Southeast 

Atlantic, California, the New England and Mid-Atlantic, portions 

of Hawaii, and the Pacific Northwest coasts of Oregon and 

Washington.

Similar to the earlier reports in this series, this report 

summarizes the methods of analysis, documents and describes 

the results of the analysis, and explains historical trends 

and rates of shoreline change. This Alaska shoreline change 

assessment differs from previously published shoreline change 

assessments in that: (1) only two historical shorelines (from 

the 1940s and 2000s eras) were available for the Alaska study 

area whereas four or more shorelines (from 1850 to 2002) were 

available for the other assessments and, thus, only end-point 

rates for one long-term analysis period are reported here, 

compared to a combination of long-term and short-term rates 

as reported in other studies; (2) modern (2000s era) shorelines 

National Assessment of Shoreline Change—

Historical Shoreline Change along the North Coast of 

Alaska, U.S.–Canadian Border to Icy Cape

By Ann E. Gibbs and Bruce M. Richmond

in this study represent a visually derived land-water interface 

position versus an elevation based, tidally referenced shoreline 

position; and (3) both exposed open-ocean and sheltered 

mainland-lagoon shorelines and rates of change are included 

in this study compared to other locations where only exposed 

open-ocean sandy shorelines or bluff edges were evaluated. 

No distinction was made between sand or gravel beaches, and 

the base of the unconsolidated coastal bluff was considered the 

shoreline where no fronting beach existed.

Shoreline change was evaluated by comparing historical 

shorelines derived from circa-1940s (1947 and 1949) 

topographic surveys and circa-2000s (1997–2012) vertical 

aerial photography, satellite imagery, and digital elevation 

models derived from lidar (light detection and ranging) 

surveys, thus producing an assessment for a 50- to 64-year 

time period. Shoreline change rates were calculated using the 

end-point method at transects spaced approximately every 

50 m along both the mainland and barrier island coasts. 

Shorelines were not delineated nor change rates calculated 

for river deltas because of the high natural variability and 

complexity of these shoreline reaches. The rates of change 

presented in this report represent conditions up to the date of 

the most recent shoreline data and, therefore, are not intended 

for predicting future shoreline positions or rates of change. 

Future updates to this assessment will include shorelines 

derived from circa-1979 Alaska High Altitude Photography 

and 2009–2012 high-resolution coastal lidar elevation 

datasets.

The study area was subdivided into a total of 10 

regions for the purposes of reporting regional trends in 

shoreline change rates. Shoreline change rates were derived 

from 26,567 individual transects, of which 84 percent 

were erosional. In order to maintain consistency with 

other National Assessment of Shoreline Change reports, 

the term “erosion” is used in this study to indicate the 

measured landward movement or retreat of the shoreline. 

No distinction is made between physical erosion and land 

loss or shoreline retreat as a result of breaching of coastal 

lake shorelines or flooding of the coast due to sea-level 

rise or land subsidence; in this context erosion and retreat 

are interchangeable. Accretion is the measured seaward 
2 National Assessment of Shoreline Change—Historical Shoreline Changes along the North Coast of Alaska

progradation of the shoreline and, particularly in case of 

barrier island and spits, also may represent the migration 

alongshore of a landscape feature. The average rate of 

shoreline change for the entire study area was -1.4 meters per 

year (m/yr) (range -18.6 to +10.9 m/yr) with an individual 

transect uncertainty of ±0.3 m/yr. Maximum erosion rates 

(18.6 m/yr) are some of the highest in the world, but are 

restricted to small sections of the north coast of Alaska . 

Average shoreline change rates along Beaufort Sea coast are 

nearly six times higher (-1.7 m/yr) than along the Chukchi 

Sea coast (-0.3 m/yr). The highest rates of both erosion and 

accretion in the study area were measured within Region 6 

(Cape Halkett to Drew Point), with rates of erosion greater 

than 18 m/yr between Cape Halkett and Pogik Bay, and rates 

of accretion greater than +10.5 m/yr on the western side of 

Pogik Bay. The highest average rates of shoreline change 

(-5.8 m/yr) were measured within Region 6, and the lowest 

(-0.3 m/yr) along the Chukchi coast in Regions 9 and 10 

(Barrow to Icy Cape).

Sheltered mainland-lagoon shorelines comprise 42 percent 

of all transects in the study area and are 88 percent erosional. 

Open-ocean exposed shorelines comprise 58 percent of all 

transects and are 81 percent erosional. Average shoreline change 

rates along exposed shorelines are twice as high (-1.8 m/yr) 

compared to sheltered shorelines (-0.9 m/yr). Barrier shoreline 

transects (includes barrier islands, spits, and beaches) comprise 

29 percent of the total transects and 50 percent of all exposed 

shoreline transects. Average shoreline change rates on barrier 

Map of the north coast of Alaska study area showing color-coded shoreline change rates, the boundaries of the ten analysis regions 

(dashed boxes and numbers), and key geographic locations discussed in the report. 

6 7

8

2 1

4

5

9

10

3

160°W 155°W 150°W 145°W 140°W

72°N

71°N

70°N

0 50KILOMETERS

0 50MILES

Shoreline Change Rates (m/yr)

-18.6 to -5.0

 -5.0 to -2.0

 -2.0 to -0.3

 -0.3 to + 0.3 +0.3 to + 2.0 +2.0 to + 5.0

 +5.0 to +10.9

EXPLANATION

Smith Bay

Point Barrow

Prudhoe Bay

Barter Island

Kaktovik

Demarcation

Bay

Harrison

Bay

Elson Lagoon

Peard Bay

Icy Cape

Drew Point

Camden Bay

Cape Halkett

Pogik

Bay Wainwright

BEAUFORT SEA

CHUKCHI SEA

ARCTIC NATIONAL WILDLIFE REFUGE

NATIONAL PETROLEUM RESERVE ALASKA

U.S.-Canadian border

shorelines are not significantly different than exposed mainland 

shorelines (-1.7 and -1.8 m/yr, respectively); however, the 

barrier transects have the lowest percent of erosional transects 

(75 percent) and highest accretional (25 percent) of all shoreline 

types. Considerable migration and translation in the position of 

the barrier islands and spits during the analysis period resulted 

in substantial erosion and accretion; however, because of the 

lack of overlapping shoreline positions, some of these changes 

could not be measured using the Digital Shoreline Analysis 

System method of analysis, particularly in Regions 3, 4, and 

8. An analysis of changes in the surface area of those barrier 

islands in those regions, however, indicates a net gain in barrier 

island surface area of nearly 1.7 million square meters, or 

about 10 percent, during the study period. A volumetric change 

analysis could not be completed because of the lack of elevation 

values for the historical datasets.

In contrast to the majority of the Nation’s shorelines, 

for all but 3 months of the year (July–September), the 

north coast of Alaska is protected by landfast sea ice from 

processes such as waves, winds, and currents that typically 

drive coastal change on beaches in more temperate regions 

of the world. Projected and observed increases in periods of 

sea-ice free conditions, as sea-ice melts earlier and forms 

later in the year, particularly in the autumn, when large 

storms are more common in the Arctic, suggest that Arctic 

coasts will be more vulnerable to storm surge and wave 

energy, potentially resulting in accelerated shoreline erosion 

and terrestrial habitat loss in the future.
Introduction 3

Introduction

U.S. Geological Survey National Assessment of 

Shoreline Change

Sandy beaches are some of the most popular tourist 

and recreational destinations in the United States, and 

coastal property constitutes some of the most valuable 

real estate in the country. Beaches are a dynamic interface 

between water and land with unique and complex natural 

ecosystems that are highly vulnerable to multiple natural 

hazards that can include flooding and drainage problems, 

effects of storms, sea-level rise, coastal erosion, and 

tsunami inundation. Partly in response to increasing 

coastal hazards, the U.S. Geological Survey (USGS) is 

conducting a nationwide assessment of coastal change. 

One component of this effort, the National Assessment of 

Shoreline Change (NASC) Project, documents changes in 

shoreline position as a proxy for coastal change. Shoreline 

position is one of the most commonly monitored indicators 

of environmental change (for example, Dolan and others, 

1991; Fletcher, 1992; Morton, 1996; Douglas and others, 

1998; Galgano and others, 1998), and it is an easily 

understood feature representing the historical movement of 

beaches.

A principal component of the USGS shoreline change 

research is to develop a common methodology so that 

shoreline change analyses can be updated periodically in a 

consistent and systematic manner. The primary objectives 

of the national assessment are to conduct research on 

improved methods of assessing and monitoring shoreline 

movement and develop a better understanding of the 

processes controlling shoreline change. Achieving these 

ongoing long-term objectives requires research that (1) 

examines the original sources of shoreline data (maps, 

aerial photographs, global positioning system [GPS], and 

light detection and ranging [lidar]); (2) evaluates the use 

of different shoreline proxies (geomorphic feature, water 

mark, tidal datum, and elevation), including the errors 

associated with each data source; (3) investigates bias 

and potential errors associated with integrating different 

shoreline proxies from different sources; (4) develops 

standard, uniform methods of shoreline change analysis; 

(5) examines the effects of localized human activities on 

shoreline movement and rates of change; and (6) integrates 

shoreline change observations with other information, such 

as geologic framework and sediment transport data.

Results of the NASC Project are organized by coastal 

regions. Previous investigations include analyses and 

descriptive reports, as well as the Geographic Information 

System (GIS) data used in the analyses for the Pacific 

Northwest (Kratzmann and others, 2013; Ruggiero and 

others, 2013), the Hawaiian Islands (Fletcher and others, 

2012; Romine and others, 2012), the New England and 

Mid-Atlantic coasts (Hapke and others, 2010; Himmelstoss 

and others, 2010), California (Hapke and others, 2006, 

2008; Hapke and Reid, 2006, 2007), the Southeast U.S. 

coast (Miller and others, 2004, 2005; Morton and Miller, 

2005), and the U.S. Gulf of Mexico (Morton and others, 

2004).

This report summarizes historical changes to 

shorelines along the north coast of Alaska between the 

U.S.-Canadian border and Icy Cape (fig. 1). Results are 

subdivided into 10 regions based on geomorphology 

for the purpose of presenting regional trends for the 

shoreline change rate data. GIS data used in the analyses 

are available from Gibbs and others (2015). The north 

coast of Alaska is a permafrost-bound microtidal coast 

with seasonal sea-ice conditions and is very different than 

the other U.S. coastlines studied by the NASC Project. 

Other differences between this study area and previous 

NASC study sites are the relative lack of tourist beaches 

and coastal tourism infrastructure, limited historical 

datasets, poor geodetic control and lack of a precise geoid 

model (a model of global mean sea level that is used to 

measure precise surface elevations), and very limited 

information on water levels or tidal datums. This report 

documents the coastal change hazard at regional scales 

and strives to relate this hazard to the body of knowledge 

regarding coastal geology of the northern Alaska region. 

Coastal change can have substantial impacts on local 

inhabitants, natural and cultural resources, habitat of U.S.-

protected Trust species (many of which are threatened 

or endangered), Department of Defense and oil and gas 

industry related infrastructure, and organic carbon input 

into the marine environment.

This report is part of a series of reports summarizing 

methods, results, and implications of the results in 

addition to maps illustrating rates of shoreline change. 

The format, style, and methods used in this report closely 

follow that developed by Hapke and others (2006, 2011). 

Rates of shoreline change are published in this report 

for the purpose of regional characterization to identify 

coastal change hazard areas. The shoreline change results 

and products prepared by the USGS are not intended for 

detailed site-specific analysis of shoreline movement, 

nor are they intended to replace any official sources of 

shoreline change information identified by local or State 

government agencies, or other Federal entities that are 

used for regulatory purposes. Rates of shoreline change 

presented herein may differ from other published rates, 

and differences do not necessarily indicate that the other 

rates are inaccurate. Some discrepancies are expected, 

considering the many possible ways of determining 

shoreline positions and rates of change, and the inherent 

uncertainty in calculating these rates. Rates of shoreline 

change presented in this report represent shoreline 

movement under past conditions. The results are not 

intended for predicting future shoreline positions or future 

rates of shoreline change.
4 National Assessment of Shoreline Change—Historical Shoreline Changes along the North Coast of Alaska

Figure 1. Shaded relief index map of the north coast of Alaska showing study area (U.S.-Canadian Border to Icy Cape; rectangular 

box) and key geographic locations.

170°W 165°W 160°W 155°W 150°W 145°W 140°W

71°N 70°N 69°N 68°N 67°N 66°N

National Petroleum Reserve - Alaska

Arctic National Wildlife Refuge

Icy

Cape

U.S. - Canadian Border

Barter

Island

Pt. Barrow

Prudhoe

Bay

Peard Bay

Cape

Halkett

Beaufort Sea

UTM zone 6

Cape Lisborne

Kotzebue

Sound

Point

Hope

Chukchi Sea

UTM zone 7 UTM zone 3 UTM zone 4 UTM zone 5

Barrow

Colville River

Delta

Wainwright

Drew

Point

Kaktovik

Cape

Thompson

The Role of State and Federal Governments

One reason for conducting this national assessment 

of shoreline change is that there is no widely accepted, 

standardized method of analyzing shoreline change. Each 

State or region has its own data needs and coastal-zone 

management responsibilities (for example, construction 

set-back lines, dune protection zones, and public access) 

and, therefore, each State uses a different technique and 

standard to compile shorelines and calculate rates of shoreline 

movement. Consequently, calculated rates of shoreline change 

and projected erosion hazard zones are inconsistent from 

State to State and often cannot be compared directly. These 

inconsistencies were clearly demonstrated by the Federal 

Emergency Management Agency (FEMA)-sponsored erosion 

studies (Crowell and Leatherman, 1999) that were used as the 

basis for evaluating erosion hazards (The H. John Heinz III 

Center for Science, Economics, and the Environment, 2000). 

The USGS national assessment of shoreline change represents 

the first effort to compile shorelines from original data sources 

and calculate rates of shoreline change on a national scale 

using internally consistent methods. The results of the analyses 

allow direct comparison of rates of change from one coastal 

segment to another and form the basis for future comparison 

of shoreline position.

Several Federal agencies (U.S. Geological Survey [USGS], 

Federal Emergency Management Agency [FEMA], National 

Oceanic and Atmospheric Administration [NOAA], and U.S. 

Army Corps of Engineers [USACE]) have regulatory or 

administrative responsibilities pertaining to shorelines. These 

responsibilities are different, however, and require different 

approaches. They also offer substantial opportunities for 

cooperation. For example, the USACE is authorized and funded 

by Congress to report on the economic and environmental 

implications of shoreline change and the costs of erosion 

mitigation. Its National Shoreline Management Study (Stauble and 

Brumbaugh, 2003) is being conducted using existing shoreline 

data. The USGS shares data and information, such as the lidarderived shoreline and rates of change, in support of that effort. 

NOAA has a mandate to establish the official shoreline boundary 

for the Nation using tidal datums. The emphasis of NOAA’s 

mandate is on safe navigation and using the shoreline to generate 

nautical charts. NOAA also conducts the VDatum program, which 

assists agencies in delineating shorelines for various purposes. 

Congress authorized and funded FEMA to report on the economic 

effect of erosion hazards on coastal communities, and on claims 

to the National Flood Insurance Fund. To accomplish this goal, 

FEMA contracted with State agencies and academic researchers 

to conduct a pilot study of erosion hazards that included 

shoreline change data for limited geographic areas. The USGS is 
Previous National and Northern Alaska Shoreline Assessments 5

responsible for conducting research pertaining to coastal change 

hazards, understanding the processes that cause coastal change, 

and developing models to predict future change. The USGS is 

the only government agency that has a dedicated program to 

monitor coastal change into the future using consistent methods 

nationwide. This program is critically important for the assessment 

of national issues such as the coastal effects of sea-level rise and 

climate change.

Previous National and Northern Alaska 

Shoreline Assessments

The U.S. Army Corps of Engineers (1971) conducted 

the first national assessment of coastal erosion. That study 

identified areas of critical and non-critical erosion on the 

basis of economic development and potential for property 

loss, but rates of shoreline movement were not evaluated. 

Dolan and others (1985) conducted a comprehensive analysis 

of shoreline change for most of the United States Their 

analysis was based on compilation of rates of shoreline 

change contributed by other investigators and derived from 

their own studies. Rates of change were presented and longterm trends of erosion and accretion were summarized. They 

mapped most of the north coast of Alaska as either severely 

or moderately eroding.

Early shoreline studies of the north coast of Alaska relied 

on geomorphic evidence to determine relative coastal stability. 

Erosion of the coast was first reported by Leffingwell (1919), 

who used fresh erosional bluff and bank scarps as evidence of 

recent erosion. He also noted that retreat rates probably varied 

with proximity of sea ice to the shore and suggested retreat rates 

may be more than 30 m/yr (100 ft/yr) at Drew Point (fig. 1). 

MacCarthy (1953) observed that, although protected from wave 

action by sea ice for much of the year, rapid coastal erosion is 

evident for much of the coast around the Barrow Peninsula.

Quantitative studies of regional shoreline change 

along parts of the coast of Alaska were conducted by 

Harper (1978), Reimnitz and others (1985, 1988), Barnes 

and Rollyson (1991), Barnes and others (1992), Jorgenson 

and Brown (2005), Mars and Houseknecht (2007), Jones 

and others (2008, 2009a), and, more recently, by Lantuit 

and others (2011). The results of these studies are briefly 

summarized: 

• Harper (1978) measured cliff and waterline retreat 

rates along the Chukchi Sea coast for a 27-year 

period (1948/49–1976) by comparing coastal aerial 

photographs from Barrow to Peard Bay. Mean retreat 

rates for the waterline were -0.41 m/yr and coastal 

cliffs were -0.37 (cliff top) and -0.26 (cliff base) m/yr. 

Average cliff retreat rates over 5-km segments ranged 

from -0.06 to -1.50 m/yr.

• Reimnitz and others (1985, 1988) compared two 

sets of nautical charts showing shorelines for 1950 

(U.S. Coast and Geodetic Survey, C&GS) and 1980 

(National Ocean Survey, NOS) for the Beaufort 

Sea coast from the Colville River Delta to Drew 

Point (approximately 344 km). They determined an 

average erosion rate of -2.5 m/yr with rates as high as 

-18 m/yr, and large sections of coast ranging from -5 

to -10 m/yr. In contrast to widespread erosion, they 

found that the Colville River Delta was accreting at 

an average rate of +0.4 m/yr, with localized accretion 

as much as +20 m/yr. In the western third of their 

study area, where the coastal plain deposits are 

mostly fine-grained, average retreat rates were 

-5.4 m/yr, whereas towards the east, where deposits 

are composed of mostly sand and gravel, the coast 

retreats at a slower rate of -1.4 m/yr.

• Barnes and Rollyson (1991) and Barnes and others 

(1992) used a similar methodology to Reimnitz and 

others (1985, 1988) using 1951 and 1981 charts to 

examine approximately 300 km of the Beaufort Sea 

coast from Flaxman Island to the Canadian Border. 

They measured a total average coastal change rate of 

0.36 m/yr (accretion), but with a net coastal-volume 

loss of 400 (m3/km)/yr. They found extensive bluff 

erosion to be nearly offset by delta accretion, and 

coastal change was nearly an order of magnitude less 

than the Reimnitz and others (1985, 1988) study area 

to the west.

• Jorgenson and Brown (2005) summarized most of the 

regional and local erosion data for the Beaufort Sea coast 

from previous studies in an effort to estimate carbon 

and sediment inputs to the Beaufort Sea from eroding 

shorelines. They found mean annual erosion rates varied 

by coastline type, with -0.7 m/yr for lagoon shorelines 

(maximum -10.4 m/yr) and -2.4 m/yr for exposed bluff 

shorelines (maximum -16.7 m/yr). Additionally, they 

reported higher rates for shorelines composed mostly 

of silt material (-3.2 m/yr) than for predominantly sand- 

(-1.2 m/yr) to gravel-dominated (-0.3 m/yr) coasts.

• Mars and Houseknecht (2007) examined 50 years 

of coastal change along approximately 130 km of 

coastline in the northeastern National Petroleum Reserve 

in Alaska (NPR-A) using 1955 USGS 1:250,000 

topographic maps and 1985 and 2005 Landsat 5 

imagery. They measured an approximate doubling in the 

average rate of coastal land loss for the two time periods 

examined: 1955–1985 (-0.5 km2/yr) and 1985–2005 

(-1.1 km2/yr). As much as -0.9 km of erosion occurred 

in some areas, and they reported erosion responsible for 

breaching coastal freshwater thermokarst lakes resulting 

in marine inundation.

• Jones and others (2008, 2009a) focused on a 100-km 

stretch of coast of known high erosion rates between 

Drew Point, Cape Halkett, and Harrison Bay. They 
6 National Assessment of Shoreline Change—Historical Shoreline Changes along the North Coast of Alaska

examined three time periods and documented an 

apparent acceleration in mean annual erosion rates 

between Drew Point and Cape Halkett: 1955–1979 

(-6.8 m/yr), 1979–2002 (-8.7 m/yr), and, 2002–2007 

(-13.6 m/yr). Additionally, they noted an increase in 

the uniformity of erosion and a complex relationship 

between the rate of erosion and ice content, 

thermokarst lake processes, and soil and vegetation 

characteristics of the coast. They also noted a 

decrease in erosion rates near Cape Halkett where 

erosion shifted the coast from an unvegetated thaw 

lake basin material landward to polygonal tundra 

with higher ice content and vegetative cover, which 

is more resistant to erosion.

• Lantuit and others (2011) recently summarized 

erosion rates for the entire Arctic coast where 

101,447 km of coastline was subdivided into 1,315 

segments with a resulting average retreat rate of 

-0.5 m/yr. The U.S. Beaufort Sea coast showed both 

the highest average erosion rate (-1.15 m/yr) and 

the greatest range in shoreline change rates. Lantuit 

and others (2011) also found that erosion rates 

were larger along unlithified shorelines and were 

positively correlated (weakly) to ice content.

Manley (2004) documented shoreline change near 

Barrow using orthorectified 1955 black-and-white aerial 

photographs and orthorectified 2002 radar imagery. The 

measured shoreline retreat rates were as much as 8 m/yr for 

the mainland coast and as much as 16 m/yr for the barrier 

islands.

To summarize:

• All these studies have documented localized high 

rates of shoreline retreat, especially when compared 

with the rest of the Nation.

• Shoreline retreat is widespread, chronic, and in 

settings where extremely high rates occur, as much 

as -18.1 m/yr.

• Accreting coastlines are mostly limited to deltas and 

sandy barrier extensions.

• Ice content and lithology of material composing the 

bluffs affect their erodibility, and hence, erosion 

rates. Coastlines with low ice- and mud-rich bluffs 

erode faster than higher bluffs composed of coarser 

sediment such as sand and gravel. Additionally, 

warmer air and water temperatures melt the 

ice, resulting in loss of mechanical strength and 

increased erosion.

• Several studies suggest that erosion rates have been 

accelerating (Mars and Houseknecht, 2007; Jones 

and others, 2008, 2009a; Arp and others, 2010; 

Overeem and others, 2011).

Geology and Geomorphology of the 

North Coast of Alaska

Lands of Unique Importance

The north coast of Alaska comprises large tracts of 

Federal, State, and Native Alaskan managed land, which 

includes the National Petroleum Reserve–Alaska (NPR-A), 

the Arctic National Wildlife Refuge (ANWR), the Teshekpuk 

Lake Special Area (TLSA), and the North Slope Borough.

The NPR-A is managed by the U.S. Department 

of the Interior, Bureau of Land Management (BLM). It 

encompasses nearly 9,551,000 hectares (23,600,000 acres) 

and is the largest tract of undisturbed public land in the 

United States. Several Inupiaq villages are located around 

its perimeter; the largest of which is Barrow (seat of the 

North Slope Borough). Part of the NPR-A, the Teshekpuk 

Lake Special Area (TLSA) provides important habitat to a 

wide variety of wildlife, including the Teshekpuk Caribou 

(Rangifer tarandus) Herd, muskox (Ovibos moschatus), 

brown bear (Ursus arctos), polar bear (Ursus maritimus), 

wolverine (Gulo gulo), wolves (Canis lupus), Arctic fox 

(Alopex lagopus), red fox (Vulpes vulpes), shrews (Sorex 

ugyunak), lemmings (Lemmus trimucronatus), more than a 

dozen fish species, shorebirds in unusually high densities, 

snowy owls (Nyctea scandiaca), jaegers (Stercorarius 

pomarinus), falcons (Falconidae), ravens (Corvus corax), 

and migratory waterfowl. Teshekpuk Lake is the largest 

lake in Arctic Alaska, the third largest lake in the State, and 

possibly the largest thermokarst lake on Earth (http://alaska.

usgs.gov/science/geography/studies/Teshekpuk_Lake.php; 

accessed November 22, 2014). Teshekpuk Lake is only a 

few meters above sea level and has a surface area of about 

850 km2.

The Arctic National Wildlife Refuge (ANWR) is 

the largest (78,000 km2) National Wildlife Refuge in the 

country and is administered by the U.S. Department of the 

Interior, U.S. Fish and Wildlife Service (USFWS) offices in 

Fairbanks. The refuge supports a greater variety of plant and 

animal life than any other protected area in the Arctic Circle,

and spans about 300 km (200 mi) north to south extending, 

from interior Alaska north across the Brooks Range to 

the Arctic Ocean. The Refuge’s wildlife includes 42 fish 

species, 37 land mammals, 8 marine mammals, and more 

than 200 migratory and resident bird species (http://www.

fws.gov/alaska/nwr/arctic/; accessed November 22, 2014). 

Along the northern coast of the refuge, the barrier islands, 

coastal lagoons, salt marshes, and river deltas provide habitat 

for migratory water birds, fish, caribou, polar bears, and 

seals. Situated between NPR-A and ANWR is the Prudhoe 

Bay oil field, the largest oil field in North America. The 

land is owned by the State of Alaska, which leases sites to 

commercial firms.
Geology and Geomorphology of the North Coast of Alaska 7

The North Slope Borough is the governing body for the 

North Slope, and works with the Tribes, villages, corporations, 

schools, businesses, State and Federal agencies, and industry 

to sustain the economy and balance competing subsistence and 

development interests (http://www.north-slope.org/, accessed 

November 22, 2014). The Borough has a population of 9,430 

(2010 census) and a total area of 245,440 km2 (94,763 mi2, 

larger than 39 States) of which, 229,700 km2 (88,700 mi2) is 

land and 15,700 km2 (6,000 mi2; 6.4 percent) is water.

Geologic and Tectonic Setting

Northern Alaska can be characterized by three 

physiographic regions: the mountainous Brooks Range, the 

Arctic foothills, and the low-relief Arctic coastal plain (fig. 2). 

The region has a complex plate tectonic history that includes 

Cretaceous rifting and opening of the oceanic Canada basin of 

the Arctic Ocean accompanied by rotational motion whereby 

northern Alaska moved counterclockwise (Bird, 1999). 

Northern Alaska is part of a continental fragment (Arctic 

Alaska microplate; Hubbard and others, 1987) that includes 

the coast and adjacent continental shelves, most of the Brooks 

Range, and part of northeastern Siberia. The major Alaskan oil 

accumulations owe their origin to the geologic structures created 

Arctic Foothills

Arctic Coastal Plain

170° W 160° W 150° W 140° W

70° N

68° N

66° N

0 75 150 300 Kilometers

0 75 150 300 Miles

Beaufort Sea

Chukchi Sea

EXPLANATION Brooks Range

River

< 0

0 - 100

100 - 250

250 - 500

500 - 750

750 - 1,000

1,000 - 1,500

> 1,500

Shaded Relief (elevation in m)

through the rift process; however, most of the bedrock geology 

along the North Slope is covered by younger surficial deposits. 

The younger deposits create the modern surficial landscape of 

northern Alaska.

The Late Quaternary 

Dinter and others (1990) described the late Cenozoic 

geologic history of northern Alaska and adjacent continental 

shelves. Repeated glacioeustatic marine transgressions and 

regressions during the late Cenozoic abraded the Arctic coastal 

plain and shelf and deposited a veneer of unconsolidated marine 

and non-marine deposits over the gently seaward-dipping 

bedrock surface that extends from the foothills of the Brooks 

Range to the continental shelf break. These deposits comprise 

the Gubik Formation and range in thickness from about 60 m 

onshore to a few hundred meters on the shelf. Rawlinson (1993) 

described in detail the surficial marine, fluvial, deltaic, outwash, 

glacial, eolian, and lacustrine sediments of the Gubik Formation, 

including the timing and deposits of late Cenozoic marine 

transgressions on the coastal plain. In general, the marine facies 

record episodes of interglacial higher sea levels for the onshore 

deposits. The intervening nonmarine deposits represent a wide 

range of climate conditions and sea-level positions. The coastal 

Figure 2. Relief map showing three major physiographic provinces of northern Alaska (from Amante and Eakins, 2009).
8 National Assessment of Shoreline Change—Historical Shoreline Changes along the North Coast of Alaska

plain is underlain by numerous coalescing alluvial and glacial 

outwash fans extending south from the Brooks Range (Hopkins 

and Hartz, 1978). In addition to the fans, parts of the coastal 

plain are underlain by the Pleistocene Flaxman Member of the 

Gubik Formation (Brigham-Grette and Carter, 1992), a marine 

sandy mud with abundant glaciated gravel (mostly pebble to 

cobble size) derived from a source other than the Brooks Range, 

presumably from the east. Hopkins and Hartz (1978) noted that 

the Flaxman underlies most of Tigvariak Island, Flaxman Island, 

large mainland areas between and to the east of the distributaries 

of the Canning River, as well as smaller areas near Point 

McIntyre, Heald Point, and Point Brower.

Surficial Geology and Geomorphology 

The generalized distribution of coastline type and surficial 

geology is shown in figure 3. Coastline type includes barrier 

island systems, bays and inlets, deltas, exposed coasts and bluffs 

(that is, not protected by offshore barrier islands), lagoons, 

remnant islands (islands with tundra characteristics similar to 

the adjacent mainland), and tapped basins (breached or drained 

thermokarst lakes). The generalized surficial geology includes 

marine silt and sand (glaciomarine origin with scattered pebbles 

and often associated with higher bluffs, 4–7 m high), alluvial silt, 

sand, and gravel (stream and delta deposits), eolian silt and sand, 

sandy diamicton (poorly sorted, mostly terrigenous mixture of 

mud, sand, and gravel), and glacial moraine and bedrock uplands 

well inland from the coast.

Coastal Environments

The Alaska Arctic coastal plain, stretching from Cape 

Thompson on the west to the Canadian border on the east, can 

be characterized as a low-relief (<20 m high), tundra-covered 

surface underlain by permafrost and marked by thousands of 

shallow thermokarst lakes. The shallow subsurface consists 

mostly of unconsolidated marine (near coast) and non-marine 

silt- to gravel-sized sediment (Bird, 1999).

The coastal morphology is a mixture of low-lying softsediment bluffs with varying amounts of ice content, sand and 

gravel beaches, barrier spits, offshore barrier islands, coastal 

lagoons, wetlands, and river deltas. Coastal relief, based on 

elevation at the shore, was classified by Hartwell (1973). Low 

relief coasts (<2 m high) comprise about 26 percent of the 

total coast and include barrier islands and spits, deltas, and 

low tundra coasts. Moderate relief coasts (2–5 m high) are the 

most common (44 percent) and are usually associated with 

coastal bluffs along eroding coasts. High (5–8 m high; 16 

percent) and very high (>8 m high; 10 percent) relief coasts 

also are associated with coastal bluffs where bedrock type 

exerts some control on cliff height and retreat rates.

Coastal Bluffs

Coastal bluffs are common features of the north coast of 

Alaska. The bluff elevation and composition varies across the 

region, where heights range from low scarps a few meters high 

to cliffs nearly 25 m high in the Skull Cliff area southwest of 

160°W 155°W 150°W 145°W 140°W

72°N

71°N

70°N

0 25 50 100 Kilometers

0 25 50 100 Miles

Generalized Surficial Geology

Marine Silt

Marine Sand

Alluvial Gravel and Sand

Alluvial Sand and Silt

Alluvial Gravel

Eolian Silt

Eolian Sand

Sandy Diamicton

Glacial Moraine

Bedrock-Uplands

Coastline Type

Barrier System

Bay-Inlet

Delta

Exposed Coast

Lagoon

Remnant Islands

Tapped Basin

$ BEAUFORT SEA

Smith Bay Barrow

Prudhoe Bay Barter Island

Demarcation Bay

Harrison Bay

Peard Bay

CHUKCHI SEA

Icy

Cape

Figure 3. Map showing coastline type and generalized surficial geology of study area, north coast of Alaska (modified from Ping 

and others, 2011).
Geology and Geomorphology of the North Coast of Alaska 9

Barrow on the Chukchi Sea coast. Hartwell (1973) determined 

that approximately 74 percent of the north coast of Alaska is 

fronted by bluffs of 5 m in height or less. Bluff lithology along 

the Beaufort Sea coast ranges from ice-rich predominantly 

reworked marine silt to the west (Elson Lagoon to Cape 

Halkett), to ice-poor sand in eolian deposits in the central 

region (Fish Creek), to moderately ice-rich pebbly silty sand 

towards the east (Oliktok to Demarcation Bay; Jorgenson, 

2011). Much of the northern Chukchi Sea coast is bordered by 

high cliffs exposing Quaternary marine and coastal deposits of 

the Gubik Formation.

Bluff erosion can occur by a number of process, or 

combinations thereof, including block failure, slumping, 

and flow of water-saturated sediment (Reimnitz and others, 

1988). Jones and others (2009b) described erosion of ice-rich 

bluffs occurring by a thermo-mechanical erosion process that 

includes creation of an erosional niche at the base of the bluff 

by thermal (relatively warm seawater) and mechanical (wave 

action) processes. When the niche incision exceeds the bluff 

strength, collapse occurs and the block is further degraded by 

thermal and mechanical processes in the littoral zone. This 

process is a function of sea-surface temperature, duration 

of ice-free conditions, storm wave frequency and intensity, 

and local sea level (Reimnitz and others, 1988; Jones and 

others, 2009b). Ice-wedges within the bluff further impose a 

change in along-bluff strength characteristics, creating zones 

of weakness (Hoque and Pollard, 2009). Thawing of icerich permafrost slopes can create sediment-rich mud-flows, 

producing retrogressive thaw slump deposits at the base.

Beaches and Barrier Spits

Sand and gravel beaches are common features 

throughout the study area, typically fronting coastal bluffs 

or forming barrier spit extensions from the mainland. The 

beaches are typically narrow (<10 m wide) and composed of 

fine-to-coarse sand and fine gravel. Beach sediment generally 

coarsens from west to east across the Beaufort Sea coast, 

presumably in response to an eastward coarsening of fluvial 

and bluff sediment (Reimnitz and others, 1988). The beaches 

are frozen most of the year, thawing during the summer 

months but maintaining permafrost underneath the thawed 

active layer. Active beaches have deep active layers (as deep 

as 2 m), whereas inland ridges typically have permafrost 

within 0.5 m of the surface (Jorgenson, 2011). Coastal 

currents generated by the predominant northeasterly winds 

drive sediment westward while occasional northwesterly 

autumn storms drive sediment in the opposite direction, 

although westerly sediment transport prevails (Reimnitz and 

Kempema, 1983; Barnes and others, 1988).

Barrier Islands 

Barrier islands are widespread across the north coast of 

Alaska fronting approximately 20 percent of the mainland 

coast and 13 percent of the world’s barrier islands—a total 

of 272—surround the Arctic Ocean (Stutz and Pilkey, 2011). 

Two general types of barrier islands occur in the study area: 

(1) low-lying, unconsolidated sand and gravel islands with 

a wide range of vegetation coverage from non-vegetated to 

sparsely vegetated to an extensively vegetated; (2) elevated 

tundra islands of similar composition to the mainland tundra 

coast. A combination of the two types is common. Tundra 

islands can be relic features formed during Pleistocene 

interglacial episodes of higher sea level, or, as erosional 

remnants of the coastal plain that have become isolated from 

the mainland by thermokarst subsidence and erosion.

There are a number of hypotheses that describe the 

origin and construction of barrier islands in the Arctic (for 

example, Hopkins and Hartz, 1978; Ruz and others, 1992). 

Low-lying non-vegetated to vegetated barrier island can form 

as emergent depositional shoals linked to the outer fringes 

of river deltas, or by recent (<1,000 years) deposition of 

longshore or cross-shore transported sediment including the 

breaching of spits connected to the mainland or other islands. 

Reimnitz and others (1990) describe an ice-shove process 

where sand and gravel is excavated by ice from the seabed 

in nearshore water depths and reformed into ridges along the 

shoreline.

Ruz and others (1992) put forth a model for barrier 

island construction in the southern Canadian Beaufort Sea, 

which could apply to the north coast of Alaska as well. 

In that conceptual model, sea-level rise over a landscape 

of thermokarst basins and low-relief coasts composed of 

ice and unconsolidated sediment leads to the formation of 

embayments and rapidly eroding headlands from which 

spits develop. Subsequently, spits erode and evolve into 

barrier islands primarily through the process of overwash 

and eventual breaching. Once formed, stability of the 

island depends on equilibrium between sediment supply for 

deposition and energy available to transport the sediment.

Stutz and Pilkey (2011) found that island lengths in 

the Arctic are on average (5 km) only one-half the global 

average (10 km) because of the effect of sea ice on fetch 

and thus wave energy. Storm frequency in the high and 

middle latitudes is suggested to result in shorter and 

narrower islands relative to those on swell-dominated 

low-latitude coasts and the ratio of storm wave height to 

annual mean wave height is a good indicator of the degree 

of storm influence on island evolution. They also noted the 

potential for significant climate and sea-level change this 

century underscores the need to improve understanding of 

the fundamental roles that these two factors have played 

historically in island evolution in order to predict their future 

effects on the islands.

Coastal Lagoons

Lagoons are present along large sections of the north coast 

of Alaska and are typically bordered by offshore barrier island 

chains and/or barrier spits and the mainland, or, they can be 

drowned fluvial drainage systems enclosed by tundra uplands 

such as Wainwright Lagoon. The lagoons extend alongshore for 

up to 70 km, have varying widths with maximum depths around 
10 National Assessment of Shoreline Change—Historical Shoreline Changes along the North Coast of Alaska

3–4 m (Jorgenson, 2011). They provide essential waterfowl 

habitat for significant numbers of breeding and post-breeding 

migratory birds (Lysne and others, 2004). During the summer 

months, the coastal lagoons water temperature is typically 

warmer than the adjacent seas because of heating in the shallow 

lagoons and limited ocean mixing through narrow passages.

Wetlands

Arctic wetlands occur near peatlands, shallow lakes, 

ponds, topographic lows such as low-center polygons, and 

abandoned stream channels. Coastal salt marshes, which 

occur in sheltered bays and inlets, are typically extensive 

and can accumulate (near-) continuous vegetation cover, 

however, because of the low tidal range the development of 

strong vegetation zones is limited. During summer conditions, 

the nearshore waters tend to be more brackish because of 

freshwater input increases (Jefferies, 1977). The coastal lakes 

and deltas during the summer months are associated with sedge 

and grass marshes creating an ideal habitat for migratory birds 

and foraging mammals.

Deltas

There are numerous rivers draining the northern Alaska 

coastal plain, with the Colville River being the largest and 

draining about 29 percent of the North Slope (Jorgenson, 2011). 

Fluvial sediment delivered to the coast is mostly mud to sand 

size, and more rarely gravel. Because of their closer proximity 

to the Brooks Range, the eastern rivers typically terminate 

in sand and gravel outwash fans, whereas the western river 

deltas are generally characterized by numerous shallow shoals 

and mud flats interrupted by shallow broad channels. Delta 

sediment is typically composed of mixtures of silt, fine sand, 

and finely disseminated peat in channels and flats (Rawlinson, 

1993). Reimnitz and others (1988) estimated that sediment yield 

from coastal erosion yields seven times more sediment to the 

continental shelf than that derived from streams in their study 

area along the central Beaufort Sea coast.

Permafrost

Permafrost is perennially frozen ground characteristic 

of polar regions and is an important component to landscape 

and ecological development in high latitudes. Jorgenson 

(2011) provides a summary of northern Alaska permafrost 

including permafrost development and associated coastal and 

lacustrine landforms. The Arctic coastal plain is underlain 

by continuous permafrost that extends underneath the inner 

continental shelf to about 20 m isobath (Brothers and others, 

2012). Seasonal thawing of the upper permafrost during 

summer months produces an active layer of water and 

sediment/soil. Permafrost thickness is generally greater than 

several hundred meters on the coastal plain. The northern 

Alaska coastal plain tundra surface is characterized by 

a wide variety of permafrost related small-scale surface 

features creating a patterned ground including polygons 

(low-relief low-centered, high-relief low-centered, lowrelief high centered, and high-relief high-centered), talik 

(unfrozen zones) associated with shallow lakes and gullies. 

The intersection of complex polygon boundaries with coastal 

bluffs can exert control on bluff failure mechanisms (Jones 

and others, 2009b)

Thermokarst

Thermokarst topography is widespread on the Arctic 

coastal plain and is characterized by an irregular pitted 

landscape often with small hummocks and shallow pools 

that somewhat resembles karst topography in tropical 

limestone terrains. Thermokarst lakes, also called thaw 

lakes, are freshwater bodies formed in shallow depressions. 

Thermokarst lakes and associated drained lake basins 

are widespread in permafrost lowlands with ice-rich 

sediments. Thermokarst lake formation occurs during 

permafrost degradation and is linked to surface disturbance, 

subsequent melting of ground ice, surface subsidence, water 

impoundment, and positive feedbacks between lake growth 

and permafrost thaw, whereas lake drainage generally results 

in local permafrost aggradation (Grosse and others, 2013). 

The lakes characteristically have unique limnological, 

morphological, and biogeochemical characteristics that 

are closely tied to cold-climate conditions and permafrost 

properties. They also have a tendency toward drainage 

through permafrost degradation and erosion. Thermokarst 

lake dynamics strongly affect the development of landscape 

geomorphology, hydrology, and the habitat characteristic of 

permafrost lowlands.

Dunes

Holocene dunes are present or downwind of nearly 

all active river and delta systems and along the seaward 

edge of tundra-covered barrier islands that have a beach 

(Rawlinson, 1993). Black (1951) studied the eolian deposits 

of Alaska and described the Arctic coastal plain suitable for 

eolian transport because of high winds, lack of topographic 

obstacle, low precipitation, and an abundance of silt and 

sand sediment. He also noted that permafrost and tundra 

vegetation limit modern dune formation. Eolian deposits 

of the coastal plain consist of dunes, sand sheets, and loess 

blankets, although the most widespread deposits are preHolocene in age with active dunes generally limited to river 

systems (Jorgenson, 2011).
Methods of Analyzing Shoreline Change 11

Methods of Analyzing Shoreline 

Change

Compilation of Historical Shorelines

Coastal researchers in universities and government 

agencies in the United States have been quantifying rates 

of shoreline movement and studying coastal change for 

decades. Time series of shoreline positions can be used to 

document coastal change and are interpreted to improve our 

understanding of shoreline stability. Before global positioning 

system (GPS) and lidar technologies were developed, the 

most commonly used sources of historical shoreline position 

were NOAA topographic sheets (T-sheets) (Shalowitz, 1964) 

and aerial photographs. Extraction of shoreline position from 

these data sources involves georeferencing maps or aerial 

photographs, and subsequently interpreting and digitizing a 

shoreline position. Depending on location, data source, and 

scientific preference, different proxies for shoreline position 

(shoreline reference feature) are used to document coastal 

change, including high water line (HWL), wet-dry line, 

vegetation line, dune toe or crest, toe or berm of the beach, 

cliff base or top, the line of mean high water (MHW), or a 

tide-coordinated or instantaneous land-water interface.

This study incorporates shoreline positions for two time 

periods, circa-1940s and circa-2000s derived from a variety of 

dates and data sources (table 1, fig. 4). Datasets were selected 

based on having regional coverage over a relatively consistent 

time period and that were also available in digital format and 

previously georeferenced or readily done so (for example, 

T-sheets with geographic coordinate information).

The shoreline reference features, or shoreline proxy, 

mapped in this study were the “approximate mean high 

water line” (aHWL) as defined and mapped on the 1940s era 

T-sheets and the instantaneous land-water interface on the 

2000s era photography, satellite imagery, vector shorelines, 

and lidar DEM.

Common proxies for high-water lines (for example, beach 

wrack, wet/dry line, toe or berm of the beach) were difficult to 

determine in the 2000s era data sources used in this study due 

to narrow beaches, low contrast of beach sediment, low sun 

angles, and/or lack of debris material. The intersection of the 

water line and the beachface was identified as an appropriate 

proxy and was digitized where a beach was present. Where no 

beach was present, the bluff edge was digitized. The land-water 

interface proxy for the 2000s era shoreline was generally well 

defined in all the imagery, except where obscured by clouds, 

shadows, waves, or ice. Shorelines were not digitized for highly 

variable deltaic regions and for intertidal mudflats because 

of uncertainties identifying waterline intersections on gently 

sloping shorelines. The land-water interface is not an ideal 

feature to use as a shoreline proxy because of the potentially 

wide variations in the horizontal position of the shoreline due 

to fluctuating water levels, which is especially pronounced 

in gently-sloping environments. However, because of the 

difficulties identifying other shoreline proxies outlined above, 

Table 1. Providers and original sources of historical shoreline data for the north coast of Alaska.

Organization Original data source Spatial coverage

National Oceanic and Atmospheric Administration 

(NOAA), Coastal Services Center

Scanned NOAA T-sheets (1947, 1949) All regions

U.S. Fish and Wildlife Service Pan-sharpened multispectral QuickBirdTM 

satellite imagery (2003)

ANWR coast; Staines River to the U.S.-Canadian 

border

U.S. Geological Survey Color-infrared Digital orthophotographs 

Quarter Quadrangles (2002, 2005)

NPR-A; Kikolik Creek to Colville River Delta

ConocoPhillips Color-infrared digital orthophotographs (2004, 

2006)

Fish Creek/Colville River Delta to about 9 km east 

of Oliktok Point, including Thetis, Spy, Leavitt, 

and Cross Islands

BP Exploration (Alaska), Inc. Color-infrared digital orthophotographs (2006, 

2007)

About 9 km east of Oliktok Point to about 9 km 

east of Point Thomson, including offshore 

barrier islands between Pingok and Stump 

Islands

BP Exploration (Alaska), Inc. Digitized vector shorelines from planimetric 

maps (1997, 2001)

Offshore barrier islands from Reindeer Island to 

Brownlow Point

Geographic Information Network of Alaska Alaska Statewide Orthoimagery Mosaic, 

SPOT5 satellite imagery (2010, 2011)

Eastern Peard Bay and Wainwright Inlet

U.S. Geological Survey Airborne lidar DEM (2010, 2011, 2012) Icy Cape to Kikolik Creek

[ANWR, Alaska National Wildlife Refuge; NPR-A, National Petroleum Reserve, Alaska; DEM, Digital Elevation Model; lidar, light detection and ranging]
12 National Assessment of Shoreline Change—Historical Shoreline Changes along the North Coast of Alaska

Figure 4. Index map of the north coast of Alaska showing shoreline data sources used in this study and their approximate extents.

2

3 5 4

6

7

8

9

1

10

160°W 155°W 150°W 145°W 140°W

73°N

72°N

71°N

70°N

EXPLANATION

1997/2001 BPXA vectors

2006/2007 BPXA orthophotos

2004 CP orthophotos

2003 QuickBird imagery

2002/2005 USGS DOQQs

2010-2012 lidar DEM

Analysis Regions

2010-2011 SPOT5

1947 T-Sheet footprint

1949 T-Sheet footprint

1

BEAUFORT SEA

Smith Bay

Barrow

Prudhoe Bay

Barter Island

Demarcation Bay

Harrison Bay

Peard Bay Icy Cape

CHUKCHI SEA

0 50 100 KILOMETERS

0 50 100 MILES

and because of the low diurnal tidal range along the Arctic coast 

(< 0.21 m; National Oceanic and Atmospheric Administration, 

2014), this method was deemed acceptable for this study. 

Uncertainties regarding the position of the digitized shorelines 

is discussed in section, “Estimation of Shoreline Position 

Uncertainty.”

To generate shorelines from the various imagery and 

maps, the shoreline reference features for each dataset were 

digitized in ArcGISTM at a scale of 1:1,500-7,000, depending 

on the source resolution. All shoreline vectors were converted 

to Universal Transverse Mercator (UTM) projection for their 

specific zone (zones 4-7) on the North American Datum of 

1983 (NAD 83).

1940s-Era Shorelines

Circa-1940s shorelines were delineated from 1947 or 

1949 National Ocean Service (NOS; formerly U.S. Coast and 

Geodetic Survey) T-sheets (table 2; fig. 4). Previous workers 

(Shalowitz, 1964; Crowell and others, 1991; Daniels and 

Huxford, 2001) who addressed the accuracy of T-sheets found 

that they meet national map accuracy standards (Ellis, 1978) 

and recommended them for use in shoreline change studies 

as a valuable source of data needed to extend the time series 

of historical shoreline positions (National Research Council, 

1990). The 1940s T-sheets are highly detailed and include 

survey reference points, many of which are included in the 

National Geodetic Survey (NGS) benchmark database. Roads, 

buildings, lakes and drainage patterns, muddy and marsh 

areas, hills and ridges, cliffs, bluffs, mud deposits and shoal 

areas are consistently delineated on the maps. The original 

source of the T-sheets, as discussed in the Descriptive Reports

associated with each sheet, is primarily from a combination of 

vertical and oblique aerial photography collected in June and 

July 1947 and 1949. Questionable areas were addressed using 

information acquired during corresponding hydrographic 

surveys and/or supplemental ground surveys and field 

checking completed between 1949 and 1952.

T-sheets were requested from NOAA Coastal Services 

Center (Adam Bode, written. commun., 2007) and received as 

digital (1,200 dpi), unregistered, TIFF images. T-sheets were 

georeferenced in-house using ESRI ArcMapTM 9.3 software. A 

minimum of eight ground control points (GCPs), distributed 

throughout the image on the T-sheet graticule, were used to 

apply a third order polynomial transformation. For the 1940s 

T-sheets, it was necessary to shift the graticule coordinates 

from the original mapped local datum coordinates to the 

North American Datum of 1983 (NAD 83) coordinates using 

datum transformation information provided by the National 

Geodetic Survey (NGS; Dave Doyle, written commun., 2008). 

The datum transformation was applied to T-sheet graticule 

coordinates prior to rectification.
Methods of Analyzing Shoreline Change 13

Table 2. Shorelines used to calculate change rates for the north coast of Alaska by coastal segment.

Region Date Source Type

(1) U.S.-Canadian Border to Jago River 1947

2003

T-sheet

QuickBirdTM

aHWL

LWI

(2) Jago River to Staines River 1947

2003

T-sheet

QuickBirdTM

aHWL

LWI

(3) Staines River to Sagavanirktok River 1947

2003

2006

1997

2001

T-sheet

QuickBirdTM

C-B Aerial photograph

B Aerial photograph

B Aerial photograph

aHWL

LWI

LWI

LWI

LWI

(4) Sagavanirktok River to Colville River 1947

1997

2004

2006

2007

T-sheet

B Aerial photograph

C-B Aerial photograph

C-B Aerial photograph

C-B Aerial photograph

aHWL

LWI

LWI

LWI

LWI

(5) Colville River to Cape Halkett 1947

2002

T-sheet

U Aerial photograph

aHWL

LWI

(6) Cape Halkett to Drew Point 1947

2002

T-sheet

U Aerial photograph

aHWL

LWI

(7) Drew Point to Dease Inlet 1947

2002

T-sheet

U Aerial photograph

aHWL

LWI

(8) Dease Inlet to Barrow 1947

2002

2005

T-sheet

U Aerial photograph

U Aerial photograph

aHWL

LWI

LWI

(9) Barrow to Peard Bay 1947

2005

2010

T-sheet

U Aerial photograph

Lidar DEM

aHWL

LWI

LWI

(10) Peard Bay to Icy Cape 1947

1949

2010–12

2010–11

T-sheet

T-sheet

Lidar DEM

SPOT5

aHWL

aHWL

LWI

LWI

[aHWL, approximate mean high water line; LWI, land-water interface; Lidar DEM, light detection and ranging Digital Elevation Model. Date: For details about 

dates of shoreline data used at specific locations within a region, refer to the shoreline data files available for download in the companion online data report 

(Gibbs and others, 2015). Source: C, ConocoPhillips; B, BP Alaska; U, USGS]

To verify T-sheets and datum transformations, a 

comparison was made between the georeferenced T-sheets, 

georeferenced 2000s era imagery, and published locations of 

the NGS benchmark locations, which were mapped on and 

used as survey control for the T-sheets. A problem unique to 

the north coast of Alaska, compared to the conterminous U.S. 

coast, is the relative paucity of temporally consistent, regionwide shoreline datasets and limited horizontal and vertical 

control with which to reference the geographic data. A poor 

geoid model and existing digital elevation model (DEM), 

and lack of extensive infrastructure of roads, buildings, etc. 

away from villages and oil and gas related development 

also makes it difficult to control imagery, accurately assess 

position errors, and/or compare datasets from one time period 

to the next. For this study, lake shorelines, other geomorphic 

features, benchmark locations, and limited roads, building, or 

infrastructure were used to evaluate the relative consistency 

or accuracy of the T-sheets with the assumption that most of 

these features have not changed significantly through time. 

Although there was some disagreement with lake edges near 

the corner of the sheets and with increasing distance from the 

coast, for the most part features in the datasets corresponded 

well and were within the uncertainty tolerance of the original 

scale, registration and digitization process.

2000s-Era Shorelines

Circa-2000s shorelines were developed using a 

combination of data sources including vector shorelines, 

vertical aerial photographs, satellite imagery, and a DEM 

derived from airborne lidar elevation data (table 2; fig. 4). 

1997 and 2001 vector shoreline data (provided by BP-Alaska, 

BPXA) were digitized from 1:6000 scale planimetric maps 

derived from 1:2000 CIR photography and have an estimated 

horizontal accuracy of 3.7 m (12 ft ; Ken Ambrosius, written 

commun., 2007). 2004–2007, 1-foot pixel resolution color 

orthophotograph mosaics were provided by ConocoPhillips 

(CP) and BPXA and have an estimated horizontal accuracy 
14 National Assessment of Shoreline Change—Historical Shoreline Changes along the North Coast of Alaska

of 3.0 m (10 ft ; Ken Ambrosius, written commun., 2007). 

2002 and 2005, 2.5 m pixel resolution CIR Digital Orthophoto 

Quarter Quads (DOQQs) (acquired from USGS and available 

on the EarthExplorer web site; http://earthexplorer.usgs.gov/) 

have a specified horizontal accuracy of 3.0 m RMSE (Tom 

Sturm, U.S. Geological Survey, written commun., 2011). 

2003, 0.6 m pixel resolution pan-sharpened QuickBirdTM image 

mosaics (provided by USFWS) have a stated accuracy of 6.2 m 

RMSE, according to the QuickBirdTM Imagery Products Product 

Guide.

No historical images were available for the portion of 

the Chukchi Sea coast between Kikolik Creek and Icy Cape. 

For this section, a 3-m pixel resolution digital elevation model 

(DEM) was generated from coastal lidar elevation data collected 

between 2010 and 2012. The land-water interface (shoreline) 

was interpreted and then digitized from a 30x vertical 

exaggeration hillshade derived from the DEM. Shorelines for 

the barrier islands on the eastern side of Peard Bay and at the 

mouth of Wainwright Inlet were derived from 2.5 m SPOT5 

satellite orthoimagery for 2010 and 2011, respectively (Alaska 

Statewide Orthoimagery Mosaic, accessed November 22, 2014, 

at http://www.alaskamapped.org/).

Estimation of Shoreline Position Uncertainty

Several sources of error affect the accuracy of historical 

shoreline positions and the uncertainties associated 

with the shoreline change rates calculated from them. 

Measurement uncertainties, including errors related to 

shoreline digitization, image resolution, image rectification, 

and T-sheet plotting, are related to analyst manipulation of 

the map and photograph products. For T-sheets, National 

Map Accuracy Standards (U.S. Bureau of the Budget, 1947) 

were adopted that provide a measure of both position and 

measurement uncertainties. For photographs, measurement 

uncertainty is related to the orthorectification process and 

onscreen delineation of the shoreline.

Anders and Byrnes (1991), Crowell and others (1991), 

Thieler and Danforth (1994), and Moore (2000) provided 

general estimates of the typical High Water Line (HWL) 

measurement uncertainties associated with (1) mapping methods 

and materials for historical shorelines, (2) the registration of 

shoreline position relative to geographic coordinates, and (3) 

shoreline digitizing. Using methods by Crowell and others 

(1993) and further developed and applied by Hapke and others 

(2006, 2010), we identify five uncertainty terms for HWLtype shorelines: georeferencing uncertainty (Ug ), digitizing 

uncertainty (Ud ), T-sheet survey uncertainty (Ut ), and aerial/

satellite image uncertainty (Ua ). The georeferencing uncertainty 

(Ug ) represents the maximum acceptable root mean square 

error (RMSE) for T-sheets at a scale of 1:20,000 and is applied 

to historical shorelines derived from T-sheets only. In this study, 

the total RMSE was maintained below 0.0001 degrees, which 

is approximately 11 m at this latitude. Typically, the resulting 

RMSE was much lower than 0.0001 degree. The digitizing 

uncertainty (Ud ) is the uncertainty associated with digitizing the 

shoreline and was assumed to be equal to one-half the line width 

(typically about 10 m) on the scanned T-sheets and two times the 

pixel resolution of the imagery. The maximum T-sheet survey 

uncertainty (Ut ), determined by Shalowitz (1964), incorporates 

all errors associated with the mapping process, including 

distance to rodded points, plane-table position, and identification 

of the HWL. The aerial/satellite image uncertainty (Ua ) is the 

horizontal accuracy or RMSE of the orthorectification process of 

the image data. Values were provided by the data originators and 

are different for the individual datasets (table 3).

An additional uncertainty term in our shoreline change 

analysis is the uncertainty in the position of the water line 

at the time of the survey (Upd ). Because ocean water levels 

fluctuate due to daily tides and in response to changing 

winds, waves, and air pressure, a photograph can capture the 

shoreline at a range of water levels. The tidal range along 

north coast of Alaska is only about 0.21 m (National Oceanic 

and Atmospheric Administration, 2014), however, water 

levels can become elevated or depressed up to several meters 

due to winds and low-pressure systems; westerly winds tend 

to elevate water levels at the coast, whereas easterly wind 

events tend to lower water levels (Reimnitz and Maurer, 

1979; Sultan and others, 2011; Li Erikson, U.S. Geological 

Survey, written commun., 2014). We assume these water 

level offsets were accounted for during the T-sheet mapping 

efforts, as noted in the Descriptive Reports accompanying the 

surveys, by conducting concurrent water level surveys during 

image acquisition and mapping and per standard mapping 

practices described in Shalowitz (1964). However, elevated or 

reduced absolute water levels during acquisition of the 2000s 

era datasets, have the potential to significantly modify the 

horizontal position of the shoreline as determined from the 

land-water interface, especially in low-lying areas. In order 

to estimate the positional uncertainties associated with the 

land-water interface shoreline, we evaluated water levels at the 

Prudhoe Bay tide gauge, the only continuously recording tide 

gauge on the north coast of Alaska, for the dates of acquisition 

of the aerial photographs, satellite images, and lidar data. 

The minimum and maximum value of water levels below 

and above the MHW datum for the time period during survey 

acquisition ranged between -0.19 and +0.56 m (table 4). No 

comprehensive information on regional beach slopes exists 

for the study area, however, based on limited field validation 

and the generally narrow width of beaches (< 50 m) which 

are comprised primarily of gravel and coarse sand, a slope of 

1:20, (5 percent or approximately 3 degrees), was chosen as a 

conservative estimate of beach slope for the entire study area. 

The average water level deviation from MHW for each dataset 

was multiplied by 20 to determine the estimated uncertainty of 

the land-water interface digitized water line position relative to 

MHW at the time of the survey(Upd ). This average horizontal 

position uncertainty ranges between -1.5 and +6.0 m (table 4).

Water levels at locations elsewhere along the North Slope 

can deviate significantly from those measured at Prudhoe 

Bay, near the center of the study area. To support the results 
Methods of Analyzing Shoreline Change 15

Table 3. Measurement uncertainties associated with all datasets.

Measurement uncertainty

(meters)

1947 T-sheets1997 vector shoreline2001 vector shoreline2003 QuickBirdTM2004 CPhillips photographs2006 BPXA photographs2007 BPXA photographs2002 DOQQs2005 DOQQs2010 lidar DEM2011 lidar DEM

Georeferencing (Ug ) 11 - - - - -

Digitizing (Ud ) 5 1 1 1 5 6

T-sheet survey (Ut ) 10 - - - - -

Air/satellite photograph (Ua ) - 4 6 3 3 -

High water line (Upd ) - 4.2 -0.1 -1.2 4.3 2.3 1.4 1.3 -1.5 4.3 4.9

Total shoreline position uncertainty (Up ) 15.7 5.7 3.8 6.2 5.3 4.2 3.4 6.0 6.0 7.4 7.8

[BPXA, BP-Alaska; DEM, Digital Elevation Model; lidar DEM; light detection and ranging Digital Elevation Model; DOQQs, Digital Orthophoto Quarter 

Quads; -, not applicable]

Data source Acquisition

Water level deviation from MHW

(meters)

Horizontal change

(meters)

Maximum Minimum Average Maximum Minimum Average

1997 vector 07-24-97 0.33 0.09 0.21 6.6 1.8 4.2

2001 vector 08-30-01 0.13 -0.14 0.00 2.6 -2.8 -0.1

2002 DOQQ 07-16-02 0.15 -0.03 0.06 3.0 -0.7 1.2

2002 DOQQ 07-17-02 0.26 -0.06 0.10 5.1 -1.2 2.0

2002 DOQQ 07-18-02 0.15 -0.06 0.05 2.9 -1.1 0.9

2003 QuickBirdTM 08-29-03 0.07 -0.19 -0.06 1.4 -3.8 -1.2

2004 CPhillips 07-26-04 0.23 0.20 0.22 4.6 4.0 4.3

2005 DOQQs 07-25-05 0.05 -0.19 -0.07 0.9 -3.8 -1.5

2006 BPXA 07-12-06 0.02 0.01 0.01 0.3 0.2 0.3

2006 BPXA 07-24-06 0.11 0.09 0.10 2.2 1.7 1.9

2006 BPXA 07-25-06 0.24 0.22 0.23 4.8 4.5 4.6

2007 BPXA 07-04-07 0.13 0.01 0.07 2.5 0.2 1.4

2010 lidar 07-28-10 0.26 0.00 0.13 5.2 -0.1 2.6

2010 lidar 08-02-10 0.56 0.05 0.30 11.1 0.9 6.0

2011 lidar 09-13-11 0.38 0.12 0.25 7.5 2.3 4.9

Table 4. Water level deviation from Mean High Water (MHW) and associated change in shoreline position.

[BPXA, BP-Alaska; DOQQ, Digital Orthophoto Quarter Quad; lidar; light detection and ranging]
16 National Assessment of Shoreline Change—Historical Shoreline Changes along the North Coast of Alaska

described above, we compared our results to a similar study 

(Li Erikson, U.S. Geological Survey, written commun., 2014) 

where shoreline position uncertainty estimates related to windsetup were obtained from numerical model runs in the vicinity 

of Barter Island, Alaska, about 185 km east of Prudhoe Bay. 

In this study, sustained winds up to 15 m/s oriented from the 

west were used as boundary conditions to simulate storm 

surge levels; a wind speed of 15 m/s was assumed to be the 

upper limit conditions that small aircraft obtaining aerial 

photography were able to fly (R. Wyland, U.S. Geological 

Survey, oral. commun., 2010). Shoreline position uncertainties 

were estimated to be ± 0.4 m in the vertical (±2 to ±8 m in 

the horizontal for a slope of 1:5 and 1:20, respectively) due 

to wind set-up, and ± 0.2 cm in the vertical (±1 to ±4 m in 

the horizontal for a slope of 1:5 and 1:20, respectively) due 

to astronomic tides (National Oceanic and Atmospheric 

Administration, 2014), which agree well with our observed 

and calculated values observed at Prudhoe Bay during image 

data acquisition.

For each shoreline position, the total uncertainty is found as 

the square root of the sum of squares (Taylor, 1997) of the relevant 

uncertainty terms, based on an assumption that each term is 

random and independent of the others. For shorelines derived for 

this study, the total shoreline position uncertainty at each transect i, 

is calculated following the method developed by Hapke and others 

(2006, 2010): 

 (1)

Calculation of Shoreline Change Rates

Rates of shoreline change were generated in ArcGISTM with 

the Digital Shoreline Analysis System (DSAS) version 4.3, an 

ArcGISTM extension developed by the USGS in cooperation with 

TPMC Environmental Services (Thieler and others, 2009). This 

tool allows the user to generate transects relative to a baseline 

that intersect the shorelines at a user-defined separation along the 

coast and calculate rates of change based on spatial and temporal 

differences between successive shorelines. For this analysis, 

baselines were constructed seaward of, and roughly parallel to, 

the general trend of the oldest shoreline. Using DSAS, transects 

were spaced at 50-m intervals and manually edited to assure they 

were as orthogonal to the most recent shorelines as possible and 

non-overlapping. DSAS employs the single-transect method 

(ST) to calculate change rates and rate uncertainties at regularly 

spaced transects (measurement locations) alongshore. ST uses 

various methods (for example, end point rate, linear regression 

rates, least squares, weighted least squares) to fit a trend line to 

the time series of historical shoreline positions at a transect. ST 

is the most commonly utilized method for calculating shoreline 

change (for example, see Fletcher and others, 2003; Morton and 

others, 2004; Morton and Miller, 2005; Hapke and others, 2006; 

Hapke and Reid, 2007).

Up = + Ug Ud + + Ut Ua +Upd i i i i i i

2 2 2 2 2

Because shorelines from only two time periods were 

evaluated in this study, shoreline change rates were calculated 

at each transect using the end-point rate method. The end-point 

rate is found as the difference in shoreline position between 2 

shoreline years, divided by the time between surveys. For an endpoint rate, there is no assumption that the rate was linear between 

the 2 survey years; the rate represents the net change between 

the surveys. Thus, rates of change represent averages over an 

approximately 60-year time period and do not reflect the episodic 

nature of the coastal change, particularly with regards to bluff 

retreat, which can cause substantial changes to the coastline in a 

short amount of time due to the collapse of meters-wide blocks of 

unconsolidated sediment from the bluffs.

Estimation of Shoreline Change Rate Uncertainty 

at Individual Transects

The uncertainty of a single transect’s end-point shoreline 

change rate (UR ) is found as the quadrature addition of the 

uncertainties for each year’s shoreline position, divided by the 

number of years between the shoreline surveys:

 (2)

where Up1

i

 and Up2

i are the shoreline position uncertainties of the 

first (year1) and second (year2) shorelines, 

respectively, at transect i, found through 

equation (2) (after Hapke and others, 2006). 

For this study, all transects have a (UR) value 

of 0.3 m/yr.

Estimation of Regionally Averaged Shoreline 

Change Rate Uncertainty

Regionally averaged shoreline change rates are the average 

of rates from all transects in a coastal region. The uncertainty at 

each transect is assumed to be random and independent. Therefore, 

the uncertainty of an average rate (Uavg ) can be calculated as 

the root sum of squares of rate uncertainties (UR) at all transects 

divided by n:

 (3)

The resulting average rate and uncertainty are often small 

relative to rates from individual transects. The greater the 

number of transects over which the uncertainty is averaged, 

the smaller the uncertainty of the average rate. To avoid 

reporting statistically significant average rates as indicating no 

change or having zero uncertainty, average rates were reported 

at higher precision (centimeters per year, 0.00 m/yr) than rates 

from individual transects (decimeters per year, 0.0 m/yr) (after 

Fletcher and others, 2012).

∑ = = U

U

n avg

i

n

R 1

2

= +

− U

U U

year year Ri

p i p i 1 2 2 2

2 1
Historical Shoreline Change Analysis 17

Historical Shoreline Change Analysis

For the presentation of shoreline change rates, the north coast 

of Alaska was subdivided into 10 regions (fig. 5), which are based 

broadly on coastal geomorphology and orientation of the coast. 

Barter and Tigvariak Islands were analyzed separately and only 

their exposed open-ocean shorelines are included in the regional 

averages. Index maps showing geographic locations described in 

the text are shown in figures 6–9.

In contrast to other NASC studies which evaluated only 

open-ocean sandy shorelines and coastal cliffs, this report presents 

rates for exposed open-ocean and sheltered mainland shorelines. 

We define exposed open-ocean shorelines to include mainland 

coast, barrier beaches, islands, or spits that are exposed directly 

to open-ocean wave, wind, and sea-ice conditions. Sheltered 

shorelines, typically mainland lagoon coasts, are sheltered from 

open-ocean conditions by an offshore barrier spit or island. No 

distinction was made between a sand or gravel beach versus a 

coastal bluff with no fronting beach – the shoreline mapped was 

the land-water interface whether it was a beach or the base of a 

bluff.

Each section below describes the geographical extent of the 

region, including any special features, population centers, or oil 

and gas or U.S. Department of Defense Distant Early Warning site 

(DEW) related infrastructure, followed by a summary of coastal 

geomorphology, including relative coastal elevations derived 

from airborne lidar surveys collected over the study area between 

2009 and 2012 (Gibbs and others, 2013) and Interferometric 

Synthetic Aperture Radar (InSAR) elevation data collected in 

2002, and finally a summary of shoreline change rates for the 

region as a whole and for subregions within. Table 5 summarizes 

total shoreline change rates and ranges for each of the regions and 

subregions as well as for the exposed and sheltered segments of 

the shorelines.

Along a continuous mainland coast, shorelines can 

accrete or erode through time, but are largely present from 

one year to the next. An exception to this situation along a 

mainland coast might arise near river mouth bars or spits that 

may form, erode, or migrate intermittently from year to year. 

For the most part, shoreline change rates calculated using the 

DSAS method along mainland coasts provide a relatively 

complete assessment of the shoreline change history and the 

amount of land gained or lost through time.

On barrier coasts, however, where islands and spits can 

form, erode, and migrate through space and time, single transect 

DSAS rates may provide an incomplete or even misleading 

record of the shoreline change history because a piece of 

land may have completely eroded, formed, or migrated into 

a location where no previous landform existed during one or 

more of the analytical time periods and change rates could not 

be measured. Although we present in this report DSAS rates for 

all barrier shorelines where rates could be determined, caution 

should be used when evaluating the rates, as discussed in the 

text. For selected barrier islands and island chains in Regions 

3, 4, and 8, information on the change in total surface area of 

the barriers are reported in addition to the DSAS results. The 

surface area is the total, two-dimensional, polygonal surface 

areas (square meters) of each barrier island, digitized from the 

data sources describe above.

160°W 155°W 150°W 145°W 140°W

72°N

71°N

70°N

EXPLANATION

Analysis Region

1 U.S.-Canadian Border to Jago River

2 Jago River to Staines River

3 Staines River to Sagavanirktok River

4 Sagavanirktok River to Colville River

5 Colville River to Cape Halkett

6 Cape Halkett to Drew Point

7 Drew Point to Dease Inlet

8 Dease Inlet to Barrow

9 Barrow to Peard Bay

10 Peard Bay to Icy Cape

EXPLANATION

BEAUFORT SEA

Smith Bay

Barrow

Prudhoe Bay

Barter Island

Demarcation Bay

Harrison Bay

Peard Bay

Icy Cape

CHUKCHI SEA

6 8 7

2 1

4

5

9

10

3

0 50 100 KILOMETERS

0 50 100 MILES

Figure 5. Index map of the north coast of Alaska showing the 10 analysis regions used in this study.
18 National Assessment of Shoreline Change—Historical Shoreline Changes along the North Coast of Alaska

148°W 147°W 146°W 145°W 144°W 143°W 142°W 141°W

71°N

70°N

BEAUFORT SEA

U.S. - Canadian Border to Jago River

1 Demarcation Point

2 Demarcation Bay

3 Pingokraluk Lagoon

4 Icy Reef

5 Siku Point

6 Egaksrak River

7 Beaufort Lagoon

8 Nuvagapak Point

9 Humphrey Point

10 Griffin Point

11 Tapkaurak Lagoon

12 Jago River

13 Jago Spit

Jago River to Staines River

14 Manning Point

15 Barter Island

16 Arey Island

17 Okpilak River

18 Anderson Point

19 Collision Point

20 Konganevik Point

21 Camden Bay

22 Canning River

23 Brownlow Point

24 Staines River

Staines River to Sagavanirktok River

25 Flaxman Island

26 Point Thomson

27 Point Gordon

28 Challenge Island

29 Bullen Point

30 Mikkelsen Bay

31 Tigvariak Island

32 Stockton Islands

33 Narwhal Island

34 Foggy Island Bay

35 Foggy Island 

36 Sagavanirktok River

1

2

3

4 5 6 7 8

9

NAD 1983 UTM 6

10 12 11

13

Region 1

U.S.-Canadian Border 

to Jago River

Region 2

Jago River to Staines River

Region 3

Staines River to

Sagavanirktok River

16 15 14

17

18

19

20

21 22

23 24

26 25 27

28

30 29

31

32

33

35 34

36

15 KILOMETERS

15 MILES

0 30

0 30

Figure 6. Index map of Regions 1, 2, and 3 showing geographic names discussed in the report.
Historical Shoreline Change Analysis 19

154°W 153°W 152°W 151°W 150°W 149°W 148°W

71°N

BEAUFORT SEA

NAD 1983 UTM 5

Region 4

Sagavanirktok River

to Colville River

Region 5

Colville River 

to Cape Halkett

Region 6

Cape Halkett

to Drew Point

Sagavanirktok River to Colville River

36 Sagavanirktok River

37 Cross Island

38 Reindeer Island

39 Prudhoe Bay

40 Point Storkersen

41 Long Island

42 Beechey Point

43 Milne Point

44 Pinggok Island

45 Oliktok Point

46 Thetis Island

47 Colville River

36

38

39

40

42 41 43

44

45

46

48 47

37

Colville River to Cape Halkett

48 Tolaktovut Point

49 Fish Creek

50 Tingmeachsiovik River

51 Kalikpik River

52 Atigaru Point

53 Eskimo Islands

54 Saktuina Point

55 Harrison Bay

56 Garry Creek

49

50

51

52

54 53

55

56

57

Cape Halkett to Drew Point

57 Cape Halkett

58 Cameron Point

59 Pogik Point

60 Pogik Bay

61 Pitt Point

62 Avatanak Bight

63 McLeod Point

64 Drew Point

58

59

60

61

63 62

64

15 KILOMETERS

15 MILES

0 30

0 30

Figure 7. Index map of Regions 4, 5 and 6 showing geographic names discussed in the report.
20 National Assessment of Shoreline Change—Historical Shoreline Changes along the North Coast of Alaska

Figure 8. Index map of Regions 7 and 8 showing geographic names discussed in the report.

Region 7

Drew Point to 

Dease Inlet

Region 8

Dease Inlet to Barrow

156°W 155°W 154°W

71°N

0 5 10 KILOMETERS

0 5 10 MILES

BEAUFORT SEA

Drew Point to Dease Inlet

64 Drew Point

65 Point Poleakoon

66 Anakruak

67 Ikpikpuk River

68 Piasuk River

69 Smith Bay

70 Cape Simpson

71 Sinclair River

72 Ikiak

73 Fatigue Bay

74 Tangent Point

Smith Bay

Elson Lagoon

Dease Inlet to Barrow

75 Igalik Island

76 Sanigaruak Island

77 Martin Island

78 Cooper Island

79 Tapkaluk Islands

80 Elson Lagoon

81 Crescent Island

82 Plover Point

83 Nuwuk

84 Point Barrow

64

65

66

67

68

69

70

71

72 73

74

75

76

77

78

79

80

81 82

83 84

Admiralty Bay

Dease Inlet
Historical Shoreline Change Analysis 21

162°W 161°W 160°W 159°W 158°W 157°W

71°N

0 5 10 KILOMETERS

0 5 10 MILES

NAD 1983 UTM 4

Barrow to Peard Bay

85 North Salt Lagoon

86 South Salt Lagoon

87 Barrow

88 Walakpa Bay

89 Singaruak Creek

90 Nulavik

91 Skull Cliff

92 Kikolik Creek

93 Tachinisok Inlet

Peard Bay to Icy Cape

 94 Nalimiut Point

 95 Peard Bay

 96 Point Franklin

 97 Point Belcher

 98 Akvat

 99 Wainwright

100 Pingararok Pass

101 Akoliakatat Pass

102 Icy Cape

CHUKCHI SEA

Region 9

Barrow to Peard Bay

Region 10

Peard Bay to Icy Cape

85 86

87

88

89

90

91

92

93

102

101

100

99

98

97

96

95

94

Figure 9. Index map of Regions 9 and 10 showing geographic names discussed in the report.
22 National Assessment of Shoreline Change—Historical Shoreline Changes along the North Coast of Alaska

Table 5. Shoreline change rates for north coast of Alaska regions and subregions.

Shoreline type Subregion Number of 

transects

Average of 

rates (m/yr)

Maximum rate (m/yr) Percent of transects

Erosion Accretion Eroding Accreting Not 

changing

All transects U.S.-Canadian border to Icy Cape 26,567 -1.4 -18.6 10.9 84 16 0

REGION 1: U.S.-Canadian Border to Jago River (see fig. 10 for locations of subregions)

All transects 3,673 -1.0 -13.5 5.5 86 14 0

Sheltered All transects 1,705 -0.5 -3.0 1.7 90 9 1

Demarcation Bay 273 -0.5 -1.6 1.7 93 7 0

Demarcation Bay to Kongakut River Delta 218 -0.2 -1.0 0.4 78 22 0

Egaksrak Lagoon 162 -0.3 -1.5 0.3 86 12 2

Aichilik-Egaksrak River Delta to Pokok Bay 632 -0.6 -2.6 0.8 96 3 1

Pokok Lagoon to Jago River Delta 420 -0.5 -3.0 1.6 87 12 0

Exposed All transects 1,968 -1.4 -13.5 5.5 82 18 0

Mainland coast All transects 386 -1.4 -3.6 0.5 99 1 0

Border to Demarcation Bay 184 -1.4 -2.4 -0.4 100 0 0

Angun Lagoon to Pokok Bay 22 -0.7 -3.5 0.5 77 23 0

Pokok Bay to Pokok Lagoon 180 -1.4 -3.6 -0.2 100 0 0

Barrier coast All transects 1,582 -1.4 -13.5 5.5 77 23 0

Demarcation Bay Spits 138 -4.8 13.5 5.3 86 14 0

Demarcation Bay to Siku Entrance (Icy Reef) 462 -0.5 -2.8 2.5 82 18 0

Siku Entrance to Pokok Bay 510 -1.0 -8.7 5 21 79 0

Pokok Lagoon to Jago Entrance 494 -1.6 -7.8 5.5 68 32 0

REGION 2: Jago River to Staines River (see fig. 16 for locations of subregions)

All transects 3,464 -1.1 -16.4 9.6 84 15 0

Sheltered All transects 1,749 -0.5 -4.5 1.9 85 14 1

Jago River Delta to Okpilak-Hulahula River 

Delta

901 -0.6 -4.5 1.5 84 16 0

Okpilak-Hulahula River Delta to Sadlerochit 

River

216 -0.5 -1.6 0.3 92 8 0

Sadlerochit River to Konganevik Point 188 -0.3 -2.3 0.5 72 27 2

Konganevik Point to Staines River 444 -0.5 -1.5 1.9 92 8 0

Exposed All transects 1,715 -1.6 -16.4 9.6 83 17 0

Jago River Delta to Okpilak-Hulahula River 

Delta

488 -1.9 -16.4 9.6 68 32 0

Okpilak-Hulahula River Delta to Sadlerochit 

River

54 -2.5 -4.3 -0.5 100 0 0

Sadlerochit River to Konganevik Point 647 -1.0 -13.2 2.0 88 12 0

Sadlerochit River to Konganevik Point – without spit at Collinson Point550 -0.5 -3.1 2.0 87 13 0

Konganevik Point to Staines River 526 -2.1 -7.3 1.9 89 11 0

 Mainland/Island All transects 849 -0.9 -5.4 1.0 91 9 0

Jago River Delta to Okpilak-Hulahula River 

Delta (Barter Island)

93 -1.3 -2.6 0.9 5 95 0

Sadlerochit River to Konganevik Point 545 -0.6 -2.7 1.0 11 89 0

Konganevik Point to Staines River 190 -1.4 -5.4 0.7 95 5 0

 Barrier/Spit All transects 866 -2.4 -16.4 9.6 75 25 0

Jago River Delta to Okpilak-Hulahula River 

Delta 

395 -2.0 -16.4 9.6 61 39 0

Okpilak-Hulahula Delta to Konganevik Point 91 -1.5 -4.3 2.0 82 18 0

Okpilak-Hulahula River Delta to Konganevik 

Point - without spit at Collinson Point

135 -3.0 -13.2 2.0 88 12 0

Konganevik Point to Staines River 336 -2.6 -7.3 1.9 85 15 0

[m/y, meters per year]
Historical Shoreline Change Analysis 23

Shoreline type Subregion Number of 

transects

Average of 

rates (m/yr)

Maximum rate (m/yr) Percent of transects

Erosion Accretion Eroding Accreting Not 

changing

All transects U.S.-Canadian border to Icy Cape 26,567 -1.4 -18.6 10.9 84 16 0

REGION 2: Jago River to Staines River (see fig. 16 for locations of subregions)—Continued

Barter Island All transects 512 -0.5 -3.0 4.0 80 20 0

Exposed tundra-bluff coast 93 -1.3 -2.6 0.9 95 5 0

Exposed spits 62 -0.1 -2.8 3.2 48 52 0

Sheltered coast 357 -0.3 -3.0 3.4 81 18 0

REGION 3: Staines River to Sagavanirktok River (see fig. 23 for locations of subregions)

All transects 2,162 -1.5 -16.8 6.7 89 11 0

Sheltered All transects 1,439 -0.8 -4.4 2.7 93 6 0

Staines River to Point Gordon 560 -0.8 -4.4 1.4 93 7 0

Point Gordon to Sagavanirktok River 879 -0.8 -3.6 2.7 94 6 0

Exposed All transects 723 -3.0 -16.8 6.7 81 19 0

Flaxman Island 210 -2.3 -10.4 1.9 83 17 0

Maguire Islands 169 -1.8 -13.7 6.7 66 34 0

Stockton Islands 143 -4.6 -11.2 6.0 85 15 0

McClure Islands 93 -6.5 -16.8 3.5 92 8 0

Tigvariak Island and adjacent barrier island 108 -1.1 -7.0 2.8 86 14 0

Tigvariak Islands All Transects 236 -0.7 -7.0 2.8 88 12 0

Exposed tundra-bluff coast 48 -0.5 -1.5 0.9 83 17 0

Exposed spits 60 -1.5 -7.0 2.8 88 12 0

Sheltered coast 128 -0.4 -2.2 0.2 89 10 0

REGION 4: Sagavanirktok River to Colville River (see fig. 31 for locations of subregions)

All transects 2,973 -1.1 -14.7 7.0 85 15 0

Sheltered All transects 1,918 -0.8 -4.2 1.2 95 5 0

Heald Point to Point McIntyre 484 -0.8 -2.5 1.1 97 3 0

Point McIntyre to Kuparuk River Delta 180 -0.6 -3.7 0.9 96 4 0

Kuparuk River Delta to Milne Point 529 -0.7 -2.8 1.2 94 6 0

Milne Point to Oliktok Point 389 -1.1 -4.2 1.2 90 9 1

Oliktok Point to Colville River Delta 336 -0.8 -1.9 0.7 98 2 0

Exposed All transects 1,055 -1.6 -14.7 7.0 66 34 0

Cross Island 70 -4.7 -14.4 4.0 81 19 0

Midway Islands (Reindeer only) 44 -6.6 -10.0 -2.4 100 0 0

Stump Island to Thetis Island 941 -1.1 -14.7 7.0 63 37 0

Stump, Egg, and East Long Islands 213 -1.8 -9.2 7.0 72 28 0

West Long Island to Leavitt Island 536 -0.7 -14.7 4.1 56 44 0

Spy Islands 101 -1.4 -4.0 4.3 82 18 0

Thetis Island 93 -1.8 -6.6 4.1 65 35 0

REGION 5: Colville River to Cape Halkett (see fig. 38 for locations of subregions)

Exposed All transects 1,989 -1.1 -9.6 5.0 92 8 0

Tingmeachsoivik River to Kalikpik River 454 -0.7 -4.7 1.1 93 6 1

Tingmeachsoivik River to Kogru River 1,136 -0.5 -4.7 3.8 90 9 1

Kalikpik River to Atigaru Point 419 -0.2 -1.6 3.8 81 17 1

Atigaru Point to Kogru River 260 -0.8 -3.1 0.1 98 2 0

Kogru River to Cape Halkett 856 -1.7 -9.6 5.0 94 6 0

Kogru River to Garry Creek 413 -1.2 -5.6 1.9 97 3 0

Garry Creek to embayment 248 -2.7 -9.6 -0.3 100 0 0

Embayment to Cape Halkett 195 -1.7 -3.7 5.0 82 18 0

Table 5. Shoreline change rates for north coast of Alaska regions and subregions.—Continued

[m/y, meters per year]
24 National Assessment of Shoreline Change—Historical Shoreline Changes along the North Coast of Alaska

Shoreline type Subregion Number of 

transects

Average of 

rates (m/yr)

Maximum rate (m/yr) Percent of transects

Erosion Accretion Eroding Accreting Not 

changing

All transects U.S.-Canadian border to Icy Cape 26,567 -1.4 -18.6 10.9 84 16 0

REGION 6: Cape Halkett to Drew Point (see fig. 43 for locations of subregions)

All transects 1,545 -6.3 -18.6 10.9 90 10 0

Sheltered Pogik Bay 202 -0.5 -5.7 10.9 62 38 0

Pogik Island 124 -0.3 -4.3 6.9 72 28 0

Exposed All transects 1,343 -7.1 -18.6 7.3 94 6 0

Mainland coast 1,264 -7.0 -18.6 7.3 94 6 0

Barrier island 79 -8.8 -12.9 -5.6 100 0 0

REGION 7: Drew Point to Dease Inlet (see fig. 48 for locations of subregions)

All transects 1,315 -2.4 -16.4 3.4 92 8 0

Sheltered All transects 457 -3.2 -16.4 0.6 96 4 0

Sinclair River to Tangent Point 244 -1.3 -10.3 0.6 93 7 0

Tangent Point to Black Head 213 -5.5 -16.4 -0.4 100 0 0

Exposed All transects 858 -1.9 -6.8 3.4 89 11 0

Drew Point to Ikpikpuk River Delta 349 -1.5 -4.1 1.7 93 7 0

Cape Simpson to Kulgurak Island 509 -2.1 -6.8 3.4 89 11 0

Mainland coast 603 -1.9 -4.6 3.4 91 9 0

Barrier coast 255 -1.9 -6.8 3.4 89 11 0

REGION 8: Dease Inlet to Barrow (see fig. 53 for locations of subregions)

All transects 2,228 -2.5 -17.9 7.0 90 10 0

Sheltered All transects 1,406 -2.1 -9.9 4.9 95 5 0

Exposed All transects 822 -3.2 -17.9 7.0 82 18 0

Barrier island All transects 588 -3.9 -17.9 4.1 80 20 0

Igalik Island to Sanigaruak Pass 82 -5.6 -17.9 2.7 80 20 0

Sanigaruak Pass to Ekilukruak Entrance 228 -3.3 -13.2 4.1 76 23 0

Ekilukruak Entrance to Eluitkak Pass 278 -3.9 -10.5 3.6 82 18 0

Barrier spit All transects 234 -1.3 -3.1 7.0 89 11 0

Plover Point to Point Barrow 107 -2.2 -3.0 -0.3 100 0 0

Point Barrow to Barrow Peninsula 126 -0.6 -3.0 7.0 79 21 0

REGION 9: Barrow to Peard Bay (see fig. 60 for locations of subregions)

Exposed All Transects 1,779 -0.3 -1.2 0.7 86 14 1

Barrow to Nulavik 840 -0.2 -1.1 0.7 71 28 1

Nulavik to Peard Bay 939 -0.4 -1.2 0.3 99 1 0

REGION 10: Peard Bay to Icy Cape (see fig. 64 for locations of subregions)

All transects 5,439 -0.3 -8.5 8.0 71 29 1

Sheltered All transects 2,323 -0.3 -2.2 2.0 77 23 0

Peard Bay 856 -0.3 -2.2 1.7 87 13 0

Kilmantavi to Icy Cape 1,467 -0.3 -2.1 2.0 71 28 0

6 kilometers west of Nivat Point to Icy Cape 715 -0.6 -2.1 1.7 94 6 0

Exposed All transects 3,116 -0.4 -8.5 8.0 66 33 1

Tachinosok Inlet to Atanik 717 -0.4 -5.2 2.9 62 37 0

Point Franklin to Atanik 445 0.0 -2.7 2.9 49 51 1

Atanik to Wainwright Inlet 774 0.0 -3.9 4.1 50 49 1

Wainwright Inlet to Kilmantavi 372 0.1 -0.9 5.3 50 49 1

Kilmantavi to Icy Cape Pass 1,253 -0.8 -8.5 8.0 83 17 0

Mainland coast 716 0.0 -3.9 4.1 53 46 1

Barrier islands and spits 2,079 -0.5 -8.5 8.0 74 26 0

Barrier beaches 321 0.0 0.9 1.0 43 56 1

Table 5. Shoreline change rates for north coast of Alaska regions and subregions.—Continued

[m/y, meters per year]
Historical Shoreline Change Analysis 25

(1) U.S.-Canadian Border to Jago River

Introduction

The coast of Region 1 extends approximately 105 km 

between the U.S.-Canadian border and the Jago River Delta 

along the northern coast of ANWR (figs. 5 and 10). In contrast 

to the rest of the U.S. Beaufort Sea coast, which largely 

trends west to east and faces north, the coastline of Region 1 

generally faces northeast and trends northwest to southeast. 

The only development along this stretch of coast is the former 

Demarcation Bay Intermediate DEW Line Site at Nuvagapak 

Point. The site was closed in 1963, buildings were removed 

in 2000, and only the gravel pad and runway of the former 

airstrip remain. There are no permanent villages in this region.

This coastal reach is dominated by an extended chain of 

low-lying (<3 m high), unvegetated to poorly vegetated barrier 

islands that front narrow (<3 km wide) lagoons, embayments, 

and three large river deltas (Kongakut, Aichilik-Egaksrak, and 

Jago) (figs. 10 and 11). The sheltered mainland-lagoon coast is 

characterized by low bluffs (<3 m high, except in Demarcation 

Bay where they reach as high as 8 m), low-lying tundra, and 

numerous rivers, creeks, drainages, and deltas. Narrow (<20 m 

wide) beaches are common, although not pervasive, at the base 

of the bluffs. The mainland coast is exposed directly to the open 

ocean at only three locations: (1) east of Demarcation Bay, where 

low-lying tundra, tapped thermokarst lakes, and moderately high 

(<5 m) coastal bluffs continue to the U.S.-Canadian border; (2) a 

relatively short (<900 m) section of low-lying (<2 m) tundra on 

a narrow peninsula between Angun Lagoon and Pokok Bay; and 

(3) an approximately 9 km long stretch between Pokok Bay and 

Pokok Lagoon, where coastal bluffs reach as high as 15 m. Sand 

and gravel beaches front the mainland coast at all three locations.

The coastal plain between Demarcation Bay and the 

U.S.-Canadian border and between Pokok Bay and the 

Jago River is dominated by large thermokarst lakes. On the 

intervening coastal plain between Pokok Bay and Demarcation 

Bay, however, thermokarst lakes are rare and the coastal 

plain comprises alluvial fan, floodplain, and delta deposits 

associated with the numerous rivers draining the interior 

Brooks Range.

143°0'W 142°30'W 142°0'W 141°30'W 141°0'W

70°10'N 70°0'N 69°50'N 69°40'N

EXPLANATION

NAD83_UTM_Zone_7 Base image: LANDSATmosaic ns124_mss

0 5 10 KILOMETERS

0 5 10 MILES

Icy Reef

Pokok Bay

Jago Spit

John

River

Angun River

Angun Point Siksik River

Pokok

Lagoon

Griffin Point

Tapkaurak Point

Nuvagapak Point

(former DEW site)

Demarcation

 Bay

Demarcation 

Point Pingokraluk Lagoon

Jago Entrance

U.S.-Canadian Border

Jago River

Delta

Angun Lagoon

Siku Entrance

Humphery Point

Aichilik-Egaksrak 

River Delta Egaksrak Lagoon

Beaufort Lagoon

Tapkaurak Lagoon

Sikrelurak River

Oruktalik Lagoon

Egaksrak Entrance

Oruktalik Entrance

Kimikpaurauk River

Kongakut 

River Delta

Tapkaurak Spit

Beaufort Sea

Arctic National Wildlife Refuge

Kagiluak Creek

Siku Lagoon

Angun Entrance

Nuvagapak Entrance

Turner River

Tapkaurak Entrance

Exposed Barrier Island

Exposed Barrier Spit

Exposed Mainland

Sheltered Mainland

Figure 10. Map showing color-coded shoreline types within Region 1, U.S.-Canadian border to Jago River, north coast of Alaska.
26 National Assessment of Shoreline Change—Historical Shoreline Changes along the North Coast of Alaska

Figure 11. Aerial 

photograph characteristic 

of Region 1, U.S.-Canadian 

border to Jago River, north 

coast of Alaska, near Siku 

Entrance and Egaksrak 

Lagoon where a narrow 

lagoon separates a low-lying, 

unvegetated barrier island 

along the open coast from 

the low-lying, tundra coast 

on the landward side of the 

lagoon. Brooks Range is 

visible in the background. 

View looking south. 

(Photograph from 2006; Gibbs 

and Richmond, 2009.) 

Shoreline change rates for Region 1 were determined using 

1947 T-sheets and 2003 QuickBirdTM satellite imagery (table 2; 

fig. 4). The region is predominantly erosional (86 percent of 

transects) with combined shoreline change rates for both the 

exposed open-ocean and sheltered mainland-lagoon shorelines 

averaging -1.0 m/yr and ranging between -13.5 and +5.5 m/yr 

(fig. 12; table 5). The average shoreline change rate for exposed 

open-ocean shorelines (barrier island, spit, and mainland 

coasts) is almost 50 percent higher (-1.4 m/yr) as the regional 

average, whereas the average rate for sheltered mainland-lagoon 

shorelines is nearly one-half (-0.5 m/yr) the regional average 

(table 5).

Sheltered Mainland-Lagoon Shoreline Change

The sheltered mainland coast of Region 1 is predominantly 

erosional (90 percent of transects) with shoreline change rates 

averaging -0.5 m/yr and ranging between -3.0 and +1.7 m/yr 

(figs. 12 and 13). Average rates are some of the lowest in the study 

area and near the limit of our uncertainty estimates on individual 

transects (±0.3 m/yr). The highest rates of erosion are associated 

with the erosion of the headland at Nuvagapak Point and the loss 

of a pond west of Pokok Lagoon. The highest rates of accretion 

are associated with extension of a spit near Kagiluak Creek in 

Demarcation Bay and near the Jago River Delta.

Exposed Open-Ocean Shoreline Change

The exposed open-ocean coast of Region 1, which 

includes barrier islands, spits and mainland coast, is 

predominantly erosional (82 percent of transects) with 

shoreline change rates averaging -1.4 m/yr and ranging 

between -13.5 and +5.5 m/yr (figs. 12 and 14). The DSAS 

rate calculations do not account for the considerable 

accretion and extension of spits and barrier islands—for 

example, near Demarcation Point, Pokok Bay, Tapkaurak 

Point, and Jago Spit—because of non-overlapping 

shorelines. The highest rates of erosion in the region were 

measured on the barrier spits fronting Demarcation Bay that 

migrated landward up to 700 m between 1947 and 2003. 

Accretion rates were highest near Oruktalik Lagoon, where 

a barrier spit migrated west from Griffin Point to close the 

Oruktalik Entrance channel (fig. 15).

No significant differences in average erosion rates by 

shoreline type were observed (for example, barrier islands, 

spits, and mainland coastal types all average -1.4 m/yr); 

however, considerable differences were observed spatially, 

with higher rates of erosion and accretion associated with 

the formation and closure of inlets and the migration and 

rotation of the ends of barrier islands and spits, particularly 

fronting Demarcation Bay (table 5). The remainder of the 

open-coast shoreline experienced little net change during the 

study period. For example, most of the 30 km long Icy Reef 

barrier island fronting the Kongakut River Delta between 

Siku Entrance and Demarcation Bay changed by less than 

40 m in 56 years, although there was considerable change 

at both ends (fig. 12). Shoreline change rates were also 

generally higher west of Pokok Lagoon, which may reflect 

the formation of numerous breaches, landward migration of 

the barrier islands, and/or inlet filling.
Historical Shoreline Change Analysis 27

143°0'W 142°30'W 142°0'W 141°30'W 141°0'W

70°10'N 70°0'N 69°50'N 69°40'N

EXPLANATION

NAD83_UTM_Zone_7 Base image: LANDSATmosaic ns124_mss

0 5 10 KILOMETERS

0 5 10 MILES

Icy Reef

Pokok Bay

Jago Spit

John

River

Angun River

Angun Point Siksik River

Pokok

Lagoon

Griffin Point

Tapkaurak Point

Nuvagapak Point

(former DEW site)

Demarcation

 Bay

Demarcation 

Point Pingokraluk Lagoon

Jago Entrance

U.S.-Canadian Border

Jago River

Delta

Angun Lagoon

Siku Entrance

Humphery Point

Aichilik-Egaksrak 

River Delta Egaksrak Lagoon

Beaufort Lagoon

Tapkaurak Lagoon

Sikrelurak River

Oruktalik Lagoon

Egaksrak Entrance

Oruktalik Entrance

Kimikpaurauk River

Kongakut 

River Delta

Tapkaurak Spit

Beaufort Sea

Arctic National Wildlife Refuge

Kagiluak Creek

Siku Lagoon

Angun Entrance

Nuvagapak Entrance

Turner River

Tapkaurak Entrance Shoreline Change Rates (m/yr)

-13.5 to -5.0

 -5.0 to -2.0

 -2.0 to -0.3

 -0.3 to +0.3

 +0.3 to +2.0

 +2.0 to +5.0

 +5.0 to +5.5

Figure 12. Map showing color-coded shoreline change rates in Region 1, U.S.-Canadian border to Jago River, north coast of Alaska. 

Width of line represents shoreline change envelope, or total shoreline change over analysis period, and distance between historical 

shorelines.
28 National Assessment of Shoreline Change—Historical Shoreline Changes along the North Coast of Alaska

Figure 13. Top: Graph of shoreline change rates for sheltered mainland-lagoon coast of Region 1, U.S.-Canadian border to Jago River, 

north coast of Alaska. Gray bar is shoreline change rate uncertainty (±0.3 m/yr) for individual transects. Bottom: Map of coast of Region 

1 indicating distances measured alongshore.

Pokok Bay

Jago Spit Icy Reef

Kongakut 

River Delta Tapkaurak

Point

Nuvagapak Point

Egaksrak

Lagoon

Demarcation

Bay

Beaufort Lagoon

$

NAD 1983 UTM 7 

120 90

100

80

70

60 50

40 30

20

10

0

10

10

0 5

0 5

Distance alongshore (kilometers)

Rate of change (meters per year)

Accretion Erosion

 140 130 120 110 100 90 80 70 60 -5 -2.5 0 2.5 5  50 40 30 20 10 0

130

Kagiluak Creek

Pokok Bay

KILOMETERS

MILES

Beaufort Lagoon Demarcation Bay

U.S. - Canadian

Border

Egaksrak

Lagoon

Kagiluak

Creek

Kongacut River Delta

Nuvagapak Point Egaksrak-Aichilik River Delta

Pokok Lagoon

Niguanak River

Turner River

Turner River

Angun Point

Angun Point

Jago River

Delta

Tapkaurak Point

110

Jago

River Delta Egaksrak-Aichilik

River Delta

Pokok

Lagoon
Historical Shoreline Change Analysis 29

Figure 14. Top: Graph of shoreline change rates for exposed open-ocean coast of Region 1, U.S.-Canadian border to Jago River, north 

coast of Alaska. Gray bar is shoreline change rate uncertainty (±0.3 m/yr) for individual transects. Bottom: Map of coast of Region 1 

indicating distances alongshore.

Jago Spit Siku Lagoon

Griffin Point

Humphery Point

Tapkaurak 

Spit

Nuvagapak Point Egaksrak Lagoon Demarcation Bay

Beaufort Lagoon

Demarcation Point

$

NAD 1983 UTM 7 

110 90 100 80 70

60 50 40 30

20

10

0

10

10

0 5

0 5

Distance alongshore (kilometers)

Rate of change (meters per year)

Accretion Erosion

 -15 -10 -5 0 5 10 15

 110 100 90 80 70 60 50 40 30 20 10 0

Humphrey Point

Demarcation Point

Jago Spit

KILOMETERS

MILES

Pokok Bay

U.S. - Canadian

Border

Demarcation Bay

Icy Reef

Icy Reef

Angun EntranceNuvagapak Entrance

Siku Entrance

Oruktalik Entrance

Pokok

Lagoon

Tapkaurak

Spit

Egaksrak Entrance

Griffin Point

Kongakut 

River Delta Jago

River Delta
30 National Assessment of Shoreline Change—Historical Shoreline Changes along the North Coast of Alaska

EXPLANATION

Historical Shorelines

1947

2003

1

0 1 KILOMETER

0 MILE

John River

Pokok Creek

Pokok Lagoon

Griffin Point

Niguanak River

Tapkaurak Point

Oruktalik Lagoon

Oruktalik Entrance

143°W 142°55'W 142°50'W 142°45'W

70°6'N 70°4'N 70°2'N

Background image QuickBird satellite imagery

EXPLANATION

Shoreline Change Rates

-13.5 to -5.0

 -5.0 to -2.0

-2.0 to -0.3

-0.3 to +0.3

+0.3 to +2.0

+2.0 to +5.0

+5.0 to +5.5

0 1 KILOMETER

0 1 MILE

John River

Pokok Creek

Pokok Lagoon

Griffin Point

Niguanak River

Tapkaurak Point

Oruktalik Lagoon

Oruktalik Entrance

143°W 142°55'W 142°50'W 142°45'W

70°6'N 70°4'N 70°2'N

Figure 15. Maps showing examples of shoreline change at Oruktalik Lagoon, north coast of Alaska, where barrier 

migration resulted in the closure of Oruktalik Entrance between 1947 and 2003.
Historical Shoreline Change Analysis 31

146°W 145°30'W 145°W 144°30'W 144°W 143°30'W

70°20'N 70°N 69°50'N

UTM zone 6 UTM zone 7

NAD83_UTM_Zone_7 Base image: LANDSATmosaic ns124_mss

70°10'N

Exposed Barrier Island

Exposed Barrier Spit

Exposed Island

Exposed Mainland

Sheltered Mainland

EXPLANATION

0 5 10 KILOMETERS

0 5 10 MILES

Kaktovik

Jago

Delta

Jago River

Camden Bay

Marsh Creek

Jago

Lagoon Arey

Lagoon

Arey Island

Simpson

Cove Okpilak River

Canning River

Barter Island

Hulahula River

Anderson

Point

Kaktovik

Lagoon

Tamayariak River Konganevik Point

Sadlerochit River

Carter

Creek

Bernard

Spit Staines

River

Manning

Peninsula Collinson

Point

Katakturuk River

Kajutakrok Creek

Kuvritovik

Entrance

Okpilak-Hulahula

RiverDelta

Beaufort Sea

Brownlow Point

Figure 16. Map showing color-coded shoreline types within Region 2, Jago River to Staines River, north coast of Alaska.

(2) Jago River to Staines River

Introduction

Region 2 extends approximately 110 km along the ANWR 

coast between the Jago and Staines Rivers (fig. 16). The reach 

most notably includes Barter Island, where the village of Kaktovik 

(with a 2010 census population of 239; State of Alaska, 2015), 

the Barter Island airport, the former DEW Line Main Site, and 

the currently (2014) active North Warning System Long Range 

Radar Site (NWS-LRRS) are located. The Barter Island DEW 

site was de-activated in 1989 and upgraded to a NWS-LRRS in 

1990 (fig. 17A). The Brownlow Point DEW Line Intermediate site 

(also known as Collinson Point, Kangigivik Point, Agilguagruk, 

Camden Bay, and Nuvubaq in Inupiat) was also located in this 

region, about 50 km southwest of Kaktovik, on the eastern 

shore of Simpson Cove at Camden Bay. The site was closed and 

abandoned in 1963 and demolition of buildings and remediation 

occurred around 2000. A gravel runway and building pads remain.

The coast of Region 2 includes barrier islands, spits, and 

both exposed and sheltered mainland-lagoon coast (fig. 16). The 

mainland is segmented by five large river and delta complexes 

(Okpilak-Hulahula, Sadlerochit, Katakturuk, and CanningTamayariak and Staines) and many smaller creeks and drainages. 

The coastline generally trends E-W, includes the arcuate Camden 

Bay, and crosses two UTM zones (6 and 7).

The mainland coast is predominantly low-lying (<2 m 

high) except where higher coastal bluffs occur between Jago 

River and Barter Island, near Kajutakrok Creek, between the 

Sadlerochit River and Marsh Creek, in central Simpson Cove, 

and Konganevik and Brownlow Points. Numerous, large, tapped 

and untapped thermokarst lakes are common on both the coastal 

plain and shoreline near Arey Lagoon and west of Konganevik 

Point. In contrast, the coastal plain and shoreline near Jago 

Lagoon, most of Kaktovik Lagoon, and between the OkpilakHulahula River Delta and Konganevik Point is characterized by 

few thermokarst lakes, wide braided river channels and flood 

plains separated by low to high tundra plateaus and deeply 

incised gullies.
32 National Assessment of Shoreline Change—Historical Shoreline Changes along the North Coast of Alaska

Figure 17. Aerial photographs showing typical examples of the coast of Region 2, Jago River to Staines River, north coast of Alaska. 

A, View of the Barter Island airstrip to the west. Village of Kaktovik and white radar dome of the Barter Island Long Range Radar Station 

are visible in the upper left of the photograph. Low-lying Barter Island airstrip provides primary access to Native village of Kaktovik 

and to Radar Station. Airstrip is flooded almost annually when water levels are elevated during the passage of large storms. B, Coast 

between Anderson Point and Marsh Creek showing relatively wide beaches, ice-wedge polygons, and thaw slumps in the coastal 

tundra, and high bluffs in the background; view to the south. Note the beach material encroaching landward over the tundra surface 

and the lack of large thermokarst lakes along this coast. C, Low bluffs at the coast between Konganevik Point and Canning River. Note 

the large thermokarst lakes in the background; view to south. D, Low-lying barrier coast near Canning River. Note the narrow lagoon 

and mainland coast with numerous thermokarst lakes. (All photographs from 2006; Gibbs and Richmond, 2009.)

Barrier spits and islands discontinuously front much 

of the mainland coast of Region 2 except between the 

Sadlerochit River and Konganevik Point where the coastal 

plain is relatively steeper and higher than to the east or west. 

Extensive and well-formed barrier spits and islands front Jago, 

Kaktovik, and Arey Lagoons and also extend east and west 

on Barter Island and Brownlow Point. Narrow, discontinuous 

barrier spits and islands front the Okpilak-Hulahula River 

Delta and continue west to the Sadlerochit River and the 

spit at Anderson Point, west of Marsh Creek to Collinson 

Point, and between Konganevik Point and the Canning River 

Delta. The Okpilak-Hulahula delta complex is also fronted 

by numerous low-relief, likely intertidal, shoals. These shoals 

appear to be highly variable between datasets and are therefore 

probably active sites of erosion and deposition.

Shoreline change rates in Region 2 were determined using 

1947 T-sheets and 2003 QuickbirdTM satellite imagery (table 2; 

fig. 4). The coast is predominantly erosional (84 percent of 

transects) with combined shoreline change rates for both the 

exposed open-ocean and sheltered mainland-lagoon shorelines 

averaging -1.1 m/yr and ranging between -16.4 and +9.6 m/

yr. Average shoreline change rates along exposed open-ocean 

coasts (-1.6 m/yr) high) are more than three times higher than 

along sheltered mainland-lagoon coasts (-0.5 m/yr). Shoreline 

change rates along the barrier coasts are more than twice as high 

compared to exposed mainland and island coasts (-2.4 and -0.9 

m/yr, respectively) (fig. 18, table 5). Coastal geomorphology, 

shoreline change rates, and patterns of change within Region 2 

vary considerably and are separated into several subregions in the 

sections that follow.
Historical Shoreline Change Analysis 33

Figure 18. Map showing color-coded shoreline change rates in Region 2, U.S.-Canadian border to Jago River, north coast of Alaska. 

Width of line represents shoreline change envelope, or total shoreline change over analysis period, and distance between historical 

shorelines.

146°W 145°30'W 145°W 144°30'W 144°W 143°30'W

70°20'N 70°N 69°50'N

UTM zone 6 UTM zone 7

NAD83_UTM_Zone_7 Base image: LANDSATmosaic ns124_mss

70°10'N

Shoreline Change Rates (m/yr)

-16.4 to -5.0

-5.0 to -2.0

-2.0 to -0.3

-0.3 to +0.3

+0.3 to +2.0

+2.0 to +5.0

+5.0 to +9.6

EXPLANATION

0 5 10 KILOMETERS

0 5 10 MILES

Kaktovik

Jago

Delta

Jago River

Camden Bay

Marsh Creek

Jago

Lagoon Arey

Lagoon

Arey Island

Simpson

Cove Okpilak River

Canning River

Barter Island

Hulahula River

Anderson

Point

Kaktovik

Lagoon

Tamayariak River Konganevik Point

Sadlerochit River

Carter

Creek

Bernard

Spit Staines

River

Manning

Peninsula Collinson

Point

Katakturuk River

Kajutakrok Creek

Kuvritovik

Entrance

Okpilak-Hulahula

RiverDelta

Beaufort Sea

Brownlow Point

Sheltered Mainland-Lagoon Shoreline Change

Jago River Delta to Okpilak-Hulahula River Delta

The mainland coast between the Jago River Delta and 

the Okpilak-Hulahula River Delta is sheltered by Bernard 

Spit, Barter Island, and Arey Island, and is markedly different 

east and west of Barter Island. East of Barter Island the 

mainland coast of Jago Lagoon and the eastern two-thirds 

of Kaktovik Lagoon is characterized by moderately high 

tundra bluffs (about 2–4 m high) fronted by narrow (<25 m) 

beaches. In contrast, the coast of western Kaktovik and Arey 

Lagoons is predominantly low tundra bluffs (<2 m high) and 

lower-lying wet-sedge marsh and tapped thermokarst lake 

deposits fronted discontinuously by narrow beaches (<20 m 

wide). The Manning Peninsula, a narrow strip of land that 

extends northward from the coast and separates Jago and 

Kaktovik Lagoons, comprises narrow, unvegetated barrier 

spits and a high tundra island with ~3-m high coastal bluffs 

fronted by beaches except on the northeast side. The sheltered 

mainland-lagoon coast of Region 2 between the Jago River 

Delta and Okpilak-Hulahula River Deltas is predominantly 

erosional (84 percent of transects) with an average shoreline 

change rate of -0.6 m/yr and range of -4.5 to +1.5 m/yr. The 

only noteworthy accretion was measured on the west side of 

the Manning peninsula (figs. 18 and 19; table 5).

Okpilak-Hulahula River Delta to Sadlerochit River

The mainland coast between the Okpilak-Hulahula 

River Delta and the Sadlerochit River is sheltered by a 

discontinuous chain of low-lying barrier islands and shoals. 

The mainland-lagoon coast here is typically low-lying (<2 m) 

with discontinuous, moderately wide beaches ( <50 m wide) 

except near Kajutakrok Creek, where coastal bluffs reach up to 

5-m high and beaches are generally continuous but narrower 

(<20 m wide). The sheltered mainland-lagoon coast of Region 

2 between the Okpilak-Hulahula River Delta and Sadlerochit 

River is predominantly erosional (92 percent of transects), 

averaging -0.5 m/yr and ranging between -1.6 and +0.3 m/yr 

(figs. 18 and 19; table 5).
34 National Assessment of Shoreline Change—Historical Shoreline Changes along the North Coast of Alaska

Figure 19. Top: Graph of shoreline change rates for sheltered mainland-lagoon coast of Region 2, Jago River to Staines River, north 

coast of Alaska. Gray bar is shoreline change rate uncertainty (±0.3 m/yr) for individual transects. Bottom: Map of coast of Region 2 

indicating distances measured alongshore.

100

110

120

Kaktovik

Camden Bay

Jago

Arey Lagoon

Lagoon

Arey Island

Carter Creek

Staines River

Barter Island

Konganevik Point

$ 10 KILOMETERS

10 MILES

Distance alongshore (kilometers)

Rate of change (meters per year)

Accretion Erosion

 150 140 130 120 110 100 90 80 70 60 -5 -2.5 0 2.5 5 50 40 30 20 10 0

0 5

0 5

0

10

20 30

40

50

60

130

90

NAD 1983 UTM 6 

140

Brownlow Point

70

120

Jago

Lagoon

Arey Lagoon

Konganevik Point

Manning Point

Kaktovik

Lagoon

Okpilak-Hulahula River Delta

Sadlerochit River

Okpilak-Hulahula

River Delta

Marsh Creek

Simpson

Katakturuk Cove

River Delta

Collinson Point

Collinson Point

Canning

River Delta

Camden Bay

Staines RiverCanning River DeltaSimpson CoveMarsh Creek

Brownlow Point

Sadlerochit River

Barter Island

Sadlerochit River to Konganevik Point

Between the Sadlerochit River and Konganevik Point, the 

mainland coast is sheltered by discontinuous barrier spits and 

islands only near Anderson Point, fronting Simpson Cove, and 

the embayment east of Konganevik Point. The coast here is 

largely low lying (<2 m high), except between the Sadlerochit 

River and Marsh Creek, where bluffs reach up to 15 m high. 

Beaches are common west of Sadlerochit River, except near 

the Katakturuk River, and range in width between about 20 

and 70 m. In some locations, sand and gravel, presumably 

derived from the numerous shallow stream channels and 

gullies in the area, appear to be encroaching on the lowlying tundra landscape (fig. 17B). The sheltered mainlandlagoon coast of Region 2 between the Sadlerochit River and 

Konganevik Point is predominantly erosional (72 percent 

of transects) and shoreline change rates are extremely low, 

averaging -0.3 m/yr and ranging between -2.3 and +0.5 m/yr. 

(figs. 18 and 19; table 5).

Konganevik Point to Staines River 

Between Konganevik Point and the Staines River, the 

coast and coastal plain are quite different than to the east, 

primarily due to the predominance of numerous, large, 

tapped and untapped thermokarst lakes west of Konganevik 

Point (fig. 17C). The coast along this stretch is generally less 

than 2-m high except for isolated bluffs at Konganevik and 

Brownlow Points that reach 4-m high. The shoreline along this 

stretch of coast consists of low tundra bluffs and low-lying 

tapped thermokarst lakes. Fronting beaches are narrow (<15 m 

wide), when present. Low-lying, unvegetated barrier spits and 

islands extending east and west from Brownlow Point shelter 

much of the mainland along this stretch of coast 

(fig. 16). The sheltered mainland-lagoon coast of Region 

2 between the Konganevik Point and Staines River is predominantly erosional (92 percent of transects) with shoreline 

change rates averaging -0.5 and ranging from -1.5 to +1.9 m/

yr (figs. 18 and 19; table 5).
Historical Shoreline Change Analysis 35

Exposed Open-Ocean Shoreline Change

Exposed open-ocean shoreline types in Region 2 include 

island (Barter Island), barrier island, barrier spit, and mainland 

coast (fig. 16).

Jago River Delta to Okpilak-Hulahula River Delta

The exposed open-ocean coast between the Jago and 

Okpilak-Hulahula River Deltas comprises Bernard Spit, 

Barter Island, and Arey Island. Bernard Spit is a chain of 

three, low-lying (<2 m high), barrier islands extending 

west from the entrance to Jago Lagoon. The islands are 

unvegetated except discontinuous mats of vegetation in 

topographic lows and isolated higher vegetation near the 

western end of the island.

Bernard Spit is mapped on the 1947 T-sheet as a single, 

continuous island over 7-km long. Between 1947 and 2003, 

the island segmented into three separate islands. The eastern 

part of the island extended eastward into Jago Entrance 

channel and migrated approximately 400 m landward, the 

western end extended approximately 500 m to the west and 

prograded about 275 m seaward, while the central portion 

of the island remained relatively stable. Barter Island is a 

high tundra island with large, recurved sand and gravel spits 

extending to the east and west on the Beaufort sea coast of 

the island. The eastern spit is partially sheltered from the 

open ocean by Bernard Spit. Coastal bluffs reach up to 10-m 

high near the center of the island and the fronting beaches 

are discontinuous and typically narrow. The exposed openocean coast of Barter Island where shoreline change rates 

were calculated stretches approximately 8 km from the 

Kaktovik Airport to the west end of the Barter Island spit. 

Between 1947 and 2003, the coast of Barter Island was 

predominantly erosional except for accretion and extension 

of the spits at both the eastern and western ends of the 

island. Arey Island extends about 11 km between Kuvritovik 

Entrance and the Okpilak-Hulahula River Delta. The Arey 

Island and Lagoon system has experienced a complex 

history of shoreline change with multiple segmentation 

and island migration episodes (Li Erikson, U.S. Geological 

Survey, written commun., 2014). The 1947 T-sheets show 

Arey Island as one continuous barrier island. By 2003, 

the relatively lower and narrower eastern portion of the 

island segmented into multiple islands and migrated to the 

southwest by as much as 900 m. The apex of island eroded 

and migrated to the southwest and the western portion of the 

island remained mostly stable to slightly accretional.

The exposed open-ocean coast of Region 2 between 

the Jago River Delta and the Okpilak-Hulahula River Delta 

is erosional (68 percent of transects) with an average rate 

of shoreline change of -1.9 m/yr and range of -16.5 to 

+9.6 m/yr. The highest rates of both erosion and accretion 

within Region 2 were measured within this subsection at 

Arey Island and Bernard Spit, respectively (figs. 18 and 

20; table 5). Because of the loss of land and/or migration 

beyond a common footprint (i.e., where only one shoreline 

is present), some of the erosion and accretion of both 

Bernard Spit and Arey Island is not accounted for in the 

DSAS analysis.

In order to maintain consistency with other National 

Assessment of Shoreline Change products that evaluate 

rates of shoreline change only along exposed open-ocean 

coastlines, average rates of shoreline change for Region 2 

include only rates calculated along the exposed open-ocean 

coast of Barter Island (fig. 16). Because Barter Island is 

one of the few population centers on the North Slope, 

however, shorelines, baselines, transects, and rates of 

change are included in the GIS database (Gibbs and others, 

2015), and summarized in table 5 and fig. 21.

Okpilak-Hulahula River Delta to Sadlerochit River

Between the Okpilak-Hulahula River Delta and 

the Sadlerochit River, the exposed open-ocean coast is 

marked by a discontinuous chain of extremely low-lying 

(<1-m high), narrow (<100 m wide), and unvegetated 

barrier islands and shoals. Considerably more islands 

are apparent in the 2003 imagery than were mapped on 

the 1947 T-sheets, although extensive intertidal-subtidal 

shoals are outlined on the T-sheets (fig. 22). The emergent 

barrier islands appear to have eroded and migrated 

landward on average 143 m (range: 30-243 m) between 

1947 and 2003. Shoreline change rates were calculated 

using only emergent island areas and not the intertidal 

shoals. Shoreline change rates calculated for this section 

of coast are 100 percent erosional, with shoreline change 

rates averaging -2.5 m/yr and ranging between -4.3 and 

-0.5 m/yr (figs. 18 and 20; table 5), however, the apparent 

accretion and extension of the barrier islands that occurred 

between 1947 and 2003 is not included in the DSAS 

calculated rates because the islands migrated beyond their 

1947 footprint.

Sadlerochit River to Konganevik Point

Between the Sadlerochit River and Konganevik Point, 

the coast is exposed mainland except where spits and 

barrier islands exist near Anderson Point, fronting Simpson 

Cove, and fronting the embayment east of Konganevik 

Point. Little change to the spit at Anderson Point occurred 

between 1947 and 2003 aside from the formation of a 

narrow channel. In contrast, the spit fronting Simpson 

Cove, which in 1947 extended nearly 3 km west of Marsh 

Creek to Collinson Point, migrated on average 350 m 

onshore, eroding the former location of Collinson Point, 

and creating a new, detached island to the west. The barrier 

island fronting the embayment east of Konganevik Point 

as mapped in the 1947 T-sheets deteriorated to a narrow, 

low-lying bar, whereas the spit on the east side of the 

embayment accreted and extended further west across the 

embayment.
36 National Assessment of Shoreline Change—Historical Shoreline Changes along the North Coast of Alaska

100

110

120

Camden Bay

Jago

Lagoon

Arey Lagoon

Arey Island

Carter Creek

Bernard

Spit

Staines River

Barter

Brownlow Point Island Marsh Creek

Konganevik

Point

$ 10 KILOMETERS

10 MILES

Distance alongshore (kilometers)

Rate of change (meters per year)

Accretion Erosion

 140 130 120 110 100 90 80 70 60 -20 -15 -10 -5 0 5 10 15 20 50 40 30 20 10 0

Collinson Point

Canning River

0 5

0 5

10

20

30

40

50

60 70

80

90

100

110

120

NAD 1983 UTM 6 

0

Barter

Island

130

Konganevik Point

Arey Island

Bernard Spit

Okpilak-Hulahula

River Delta

Sadlerochit River

Simpson

Cove

Katakturuk 

River Delta

Collinson Point

Sadlerochit River

Marsh Creek

Katakturuk River Delta

Anderson Point

Okpilak-Hulahula River Delta

Canning River Delta

Kaktovik

Lagoon

Figure 20. Graph of shoreline change rates for the exposed open-ocean coast of Region 2, Jago River to Staines River, north coast of 

Alaska. Gray bar is shoreline change rate uncertainty (±0.3 m/yr) for individual transects. Bottom: Map of coast of Region 2 indicating 

distances measured alongshore.

The exposed open-ocean coast of Region 2 between 

Sadlerochit River and Konganevik Point is predominantly 

erosional (88 percent of transects) and rates of shoreline 

change average -1.0 and range between -13.2 to +2.0 m/yr. 

The barrier spit fronting Simpson Cove near Collinson Point, 

however, is by far the most dynamic feature along this stretch 

of coast and dominates the calculated shoreline change rate 

averages. Average rates calculated for this stretch are reduced 

by one-half, to -0.5 m/yr, when the erosion of the spit is 

excluded (figs. 18 and 20, table 5).

Konganevik Point to the Staines River 

The exposed open-ocean coast between Konganevik 

and the Staines River is predominantly low-lying, 

unvegetated barrier islands and spits and low-lying to 

moderately high exposed mainland coast near Konganevik 

and Brownlow Points (fig. 16). The barrier islands and 

spits along this reach are extremely low lying (<1.5-m 

high), narrow (<100-m wide), and unvegetated (fig. 17D). 

The exposed open-ocean coast of Region 2 between 

Konganevik Point and the Staines River is predominantly 

erosional (89 percent of transects) and shoreline change 

rates average -2.1 and range from -7.3 to +1.9 m/yr. The 

highest erosion rates are associated with the erosion 

and landward migration of the barrier spits and islands, 

particularly around the Tamayariak and Canning River 

Deltas (figs. 18 and 20). Average shoreline change rates 

are nearly twice as high on the barrier island-spit coasts 

compared to the exposed mainland coasts (-2.6 and 

-1.4 m/yr, respectively [table 5]).
Historical Shoreline Change Analysis 37

Figure 21. Map showing color-coded shoreline change rates for Barter Island and adjacent areas, Region 2, Jago River to Staines 

River, north coast of Alaska. Width of line represents shoreline change envelope, or total shoreline change over analysis period, and 

distance between historical shorelines.

Kaktovik

Kaktovik Lagoon

Manning

Point

Barter Island

Bernard Harbor

Kaktovik Lagoon

Bernard Spit

Arey Lagoon

143°44'W 143°40'W 143°36'W 143°32'W

70°8'N 70°6'N

EXPLANATION

Shoreline Change Rate (m/yr)

-16.5 to -5.0

-5.0 to -2.0

-2.0 to -0.3

-0.3 to +0.3

+0.3 to +2.0

+2.0 to +5.0

+5.0 to +9.6

Shoreline Position

1947

2003

Background image 2003 QuickBird

0 0.5 1 KILOMETERS

0 0.5 1 MILES

Figure 22. Map of 1947 T-sheet data overlain on 2003 QuickBirdTM satellite image showing barrier islands offshore of OkpilakHulahula River Delta and Sadlerochit River in Region 2, Jago River to Staines River, north coast of Alaska. Note the much smaller 

extent of barrier islands (solid line) and intertidal shoals (dashed line) mapped in 1947 compared to the islands and shoals apparent 

in the 2003 imagery.

144°30'W 144°20'W

70°2'N 70°1'N

3 0 0.5 1 KILOMETERS

0 0.5 1 MILES
38 National Assessment of Shoreline Change—Historical Shoreline Changes along the North Coast of Alaska

147°30'W 147°0'W 146°30'W 146°0'W

70°30'N 70°20'N 70°10'N

Background image courtesy UAF-GINA (http://alaskamapped.org/bdl); includes material © CNES 2011, Distribution Spot Image S.A., France, SICORP, USA, all rights reserved.

Exposed Barrier Island

Exposed Barrier Spit

Exposed Island

Exposed Mainland

Sheltered Mainland

EXPLANATION

0 5 10 KILOMETERS

0 5 10 MILES

Lion Point

Pole

Island

Point

Hopson

Point

Gordon

Bullen

Point Point Thomson

Mikkelsen Bay

Karluk Island

Alaska

Island

Reliance Point

Narwhal Island

Flaxman Island

Duchess

Island

Shaviovik River

McClure Islands

Tigvariak

Island

Newport Entrance

Stockton Islands

Foggy Island Bay Challenge Entrance

Mary Sachs Entrance

Kadleroshilik River

Point

Sweeney

Maguire Islands

Jeanette Island

Challenge

Island

Belvedere

Island

North Star

Island

Sagavanirktok

River

Staines River

Flaxman Island 

DEW Site

Figure 23. Map showing color-coded shoreline types within Region 3. Staines River to Sagavanirktok River, north coast of Alaska.

(3) Staines River to Sagavanirktok River

Introduction

The coast of Region 3 extends approximately 70 km 

between the Staines and the Sagavanirktok River Deltas (fig. 23) 

and generally trends E-W. Coastal development in the region 

includes oil and gas related infrastructure and remnants of the 

Flaxman Island (also known as Bullen Point) Auxiliary DEW 

site, deactivated in 1971, and the North Warning System Short 

Range Radar Station that operated from 1994 until 2007 when it 

was closed and site remediation occurred (fig. 24A). There are 

no permanent villages in this region.

The mainland coast of Region 3 is sheltered by a chain 

of barrier islands that increase in distance from the mainland 

coast from east to west. The mainland coast is segmented by the 

Shaviovik and Kadleroshilik Rivers and several small, unnamed 

rivers. Mikkelsen Bay and Foggy Island Bay are two large 

embayments separated by Tigvariak Island and the Shaviovik 

River Delta. Between the Staines River and Point Gordon, where 

the barrier islands are relatively close to shore, the coastline is 

irregular and more crenulated than to the west. The coastal plain in 

this region is generally low-lying (<3 m high; fig. 24B) although 

discontinuous bluffs up to 5 m high are present west of Point 

Gordon. Barrier spits, cuspate headlands, and baymouth bars and 

beaches fronting embayments are pervasive along the mainland 

coast. Narrow beaches, 10-50 m wide, are found throughout 

the area and are generally more common and wider east of the 

Shaviovik River. Thermokarst lakes are common on the coastal 

plain and are generally elongated in an E-W direction east of 

the Shaviovik River; west of the iver the thermokarst lakes are 

generally larger and elongated in a NW-SE orientation.
Historical Shoreline Change Analysis 39

Figure 24. Aerial photographs showing typical examples of the coast of Region 3, Staines River to Sagavanirktok River, north coast of 

Alaska. A, Former site of Flaxman Island/Bullen Point Distant Early Warning (DEW) and Short Range Radar Station; view to south west. B,

Low-lying mainland coast near Point Hopson. View to east. C, Bluffs and tapped thermokarst lake on Flaxman Island. D, Narwhal Island. 

Note ice push ridges on coast and wood wrack on the topographically higher, central part of the island. (All photographs from 2006; 

Gibbs and Richmond, 2009).

The barrier island coast of Region 3 is an approximately 

65 km long barrier chain that includes Flaxman Island, the 

Maguire Islands (North Star, Duchess, Alaska, and Challenge 

Islands), the Stockton Islands (Belvedere and Pole Islands), 

Tigvariak Islands (Tigvariak Island and an adjacent unnamed 

barrier island), and McClure Islands (Karluk, Jeanette, and 

Narwhal Islands). With the exception of the Tigvariak Islands 

the barrier islands increase in distance from the mainland coast 

from about 2 km at Flaxman and Maguire Islands to more 

than 21 km at Narwhal Island. Portions of Flaxman Island 

and Tigvariak Island are slightly elevated tundra remnant 

islands, whereas the other barrier islands are low-lying, largely 

unvegetated sand and gravel islands with multiple ridges and 

well-developed recurved spits at their ends. Debris wrack lines 

are common on the higher portions of the unvegetated islands. 

Interior shallow water bodies, both connected and unconnected 

to the sea, are common.

Shoreline change rates were determined using 1947 

T-sheets and a combination of 1997 and 2001 vector 

shorelines, 2003 QuickBirdTM satellite imagery, and 2006 and 

2007 orthorectified aerial photography (table 2; fig. 4). There 

is an approximately 2 km gap in the 2000 era imagery just 

west of the Staines River that includes part of the mainland 

coast and no rates were calculated for that area. Region 3 

is predominantly erosional (89 percent of transects) with 

combined shoreline change rates for both the mainland 

and barrier island coasts averaging -1.5 m/yr and ranging 

between -16.8 to +6.7 m/yr (fig. 25; table 5). Average 

shoreline change rates along the exposed open-ocean coast 

are more than three times as high compare to the sheltered 

mainland-lagoon coast (-3.0 and -0.8 m/yr, respectively), 

although much of the change to the barrier islands is 

not accounted for in the DSAS results due to the lack of 

overlapping shorelines.
40 National Assessment of Shoreline Change—Historical Shoreline Changes along the North Coast of Alaska

147°30'W 147°0'W 146°30'W 146°0'W

70°30'N 70°20'N 70°10'N

Background image courtesy UAF-GINA (http://alaskamapped.org/bdl); includes material © CNES 2011, Distribution Spot Image S.A., France, SICORP, USA, all rights reserved.

Shoreline Change Rates (m/yr)

-16.8 to -5.0

-5.0 to -2.0

-2.0 to -0.3

-0.3 to +0.3

+0.3 to +2.0

+2.0 to +5.0

+5.0 to +6.7

EXPLANATION

0 5 10 KILOMETERS

0 5 10 MILES

Lion Point

Pole

Island

Point

Hopson

Point

Gordon

Bullen

Point Point Thomson

Mikkelsen Bay

Karluk Island

Alaska

Island

Reliance Point

Narwhal Island

Flaxman Island

Duchess

Island

Shaviovik River

McClure Islands

Tigvariak

Island

Newport Entrance

Stockton Islands

Foggy Island Bay Challenge Entrance

Mary Sachs Entrance

Kadleroshilik River

Point

Sweeney

Maguire Islands

Jeanette Island

Challenge

Island

Belvedere

Island

North Star

Island

Sagavanirktok

River

Staines River

Flaxman Island 

DEW Site

Figure 25. Map showing color-coded shoreline change rates in Region 3, Staines River to Sagavanirktok River, north coast of Alaska. 

Width of line represents shoreline change envelope, or total shoreline change over analysis period, and distance between historical 

shorelines.
Historical Shoreline Change Analysis 41

Point Gordon Staines River

Point Sweeney

Flaxman Island

Shaviovik 

River Delta

McClure Islands

Tigvariak Island

Stockton Islands

Foggy Island Bay

Kadleroshilik 

River Delta

Sagavanirktok River

$

NAD 1983 UTM 6 

10 KILOMETERS

10 MILES

0 5

0 5

0

10

20 30

40

50

60

80 70

100 90

Distance alongshore (kilometers)

Rate of change (meters per year)

Accretion Erosion

 100 90 80 70 60 50 40 30 20 10 0

Staines River

Bullen Point

Kadleroshilik River DeltaShaviovik River Delta

Foggy Island Bay

Bullen Point

Point Thomson Point Thomson

Point Sweeney

Maguire Islands

Point Gordon

Mikkelsen Bay

Mikkelsen Bay

Sagavanirktok River

-5 5 2.5 0 -2.5

Figure 26. Top: Graph of shoreline change rates for the sheltered mainland-lagoon coast of Region 3, Staines River to Sagavanirktok 

River, north coast of Alaska. Gray bar is shoreline change rate uncertainty (±0.3 m/yr) for individual transects. Bottom: Map of coast of 

Region 3 indicating distances measured alongshore.

Sheltered Mainland-Lagoon Shoreline Change

The sheltered mainland-lagoon coast of Region 3 is 

predominantly erosional (93 percent of transects) with shoreline 

change rates averaging -0.8 m/yr and ranging between -4.4 and 

+2.7 m/yr (figs. 25 and 26). The highest rates of erosion along the 

mainland coast are associated with the migration and degradation 

of barrier spits near Point Thomson. Similar loss of barrier spits 

elsewhere in the region (for example, at Bullen Point) is not 

accounted for in the DSAS analysis because of the complete loss 

of the spits during the study period. On the west side of Mikkelsen 

Bay, erosion has resulted in the near total loss of a prominent 

headland (fig. 27). Despite the increase shoreline complexity 

and crenulation between the Staines River and Point Gordon, 

there seems to be no significant change in shoreline change rates 

associated with distance from the offshore barrier islands or 

shoreline morphology along the mainland coast (table 5).

Exposed Open-Ocean Shoreline Change

The exposed open-ocean shorelines in Region 3 are 

dominantly erosional (81 percent of transects) with shoreline 

change rates averaging -3.0 m/yr and ranging between -16.8 and 

+6.7 m/yr (figs. 25 and 28). The barrier islands show a complex 

and dynamic pattern of change, with many islands showing a 

clockwise-rotational pattern of change, with the western ends 

of the islands remaining relatively stable, prograding northward 

and/or extending to the west/southwest and the eastern portions 

eroding and/or migrating considerably landward from their 1947 

position (fig. 29). Much of this change is not accounted for in the 

DSAS analysis because of the lack of overlapping shorelines. 

Between 1947 and 1991/2006 the total barrier island area, not 

including the Tigvariak Islands, increased by 381,754 m2 (table 6). 

A detailed description of changes in island morphology and rates 

of shoreline change for the barrier islands in Region 3 follows.
42 National Assessment of Shoreline Change—Historical Shoreline Changes along the North Coast of Alaska

146°52'W 146°50'W

70°11'30"N 70°11'N 70°10'30"N 70°10'N

Background image 2006 BPXA Orthophotgraph and 1947 NOS T-Sheet

EXPLANATION

Historical Shorelines

1947

2006

0 0.25 0.5 KILOMETERS

0 0.25 0.5 MILES

147°12'W 147°10'W

70°10'30"N 70°10'N 70°9'30"N Background image 2006 BPXA Orthophotgraph and 1947 NOS T-Sheet

EXPLANATION

Historical Shorelines

1947

2006

0 0.25 0.5 KILOMETERS

0 0.25 0.5 MILES

A B

Mikkelson Bay

* 18 ft high bluff

Figure 27. Maps showing examples of shoreline change along mainland coast of Region 3, Staines River to Sagavanirktok River, 

north coast of Alaska. A, Nearly complete loss of barrier spit between Bullen Point and Savakvik Point. B, Almost 0.25 kilometers of 

shoreline erosion and loss of a headland (and “18 ft high bluff”) on the west side of Mikkelson Bay.

Table 6. Total barrier island area in Region 3, Staines River to Sagavanirktok 

River, north coast of Alaska, for each era and total change during analysis 

period, in square meters.

Island name 1940s 2000s 2000s–1940s

Flaxman Island 3,287,368 2,911,841 -375,526

Maguire Islands 632,727 1,203,616 570,890

Stockton Islands 779,673 1,014,997 235,324

McClure Islands 618,489 569,556 -48,933

Tigvariak Islands 3,834,609 3,645,970 -188,638

Total with Tigvariak Islands 9,152,865 9,345,981 193,116

Total without Tigvariak Islands 5,318,256 5,700,010 381,754
Historical Shoreline Change Analysis 43

Point Gordon

Dinkum Sands

Staines River

Point Sweeney

Challenge, Alaska Islands

Narwhal Island

Flaxman Island

Duchess, North Star

Islands

Shaviovik 

River Delta

McClure Islands

Tigvariak Island

Stockton Islands

Foggy Island Bay

Kadleroshilik River

Sagavanirktok River

$

NAD 1983 UTM 6 

10 KILOMETERS

10 MILES

0 5

0 5

0

10 20 30

50

70

90

Distance alongshore (kilometers)

Rate of change (meters per year)

Accretion Erosion

 100 90 80 70 60 50 40 30 20 10 0

Tigvariak Island Stockton Islands Flaxman Island

Narwhal Island

McClure Islands

Maguire Islands

Pole

Island Belvedere

Island

Belvedere Island

Pole Island

Sagavanirktok River

Mary Sachs Entrance

Challenge Entrance

Newport Entrance

Jeanette, Karluk

Islands

Bullen Point

Mikkelsen Bay

Maguire Islands

Newport Entrance

Jeanette, Karluk

Islands

Challenge EntranceMary Sachs Entrance

Alaska IslandDuchess IslandNorth Star Island

15 10 5 0 -5 -10 -15

Figure 28. Top: Graph of shoreline change rates for exposed open-ocean coast of Region 3, Staines River to Sagavanirktok River, north 

coast of Alaska. Gray bar is shoreline change rate uncertainty (±0.3 m/yr) for individual transects. Bottom: Map of coast of Region 3 

indicating distances measured alongshore.
44 National Assessment of Shoreline Change—Historical Shoreline Changes along the North Coast of Alaska

Lion Point

Pole Island

Point Hopson

Point Gordon

Staines River

Point Thomson

Karluk Island

Reliance Point

Flaxman Island

DuchessNorthStar Islands

McClure Islands

Tigvariak Island

Stockton Islands Newport Entrance

Foggy Island Bay

ChallengeAlaska Islands Challenge Entrance

Mary Sachs Entrance

Bullen Point

Point Sweeney

Narwhal

Island

Maguire Islands

Jeanette

Island

Belvedere Island

147°30'W 147°W 146°30'W 146°W

70°20'N 70°15'N

EXPLANATION

200x

1947

5 Kilometers 3 0 5

Miles

0

147°30'W 147°20'W

70°24'N 70°22'N

70°24'N

Karluk

Island

Narwhal Island

McClure Islands

Jeanette Island

EXPLANATION

200x

1947

0 1

Kilometers

3 0 1

Miles

Pole Island

Stockton Islands

Belvedere Island

147°W 146°50'W

70°18'N 70°16'N

EXPLANATION

200x

1947

0 1

Kilometers

3

0 1

Miles

Point Hopson

Alaska Island

Duchess Island

Maguire Islands

North Star IslandMary Sachs Entrance

Challenge Entrance

Challenge Island

146°40'W 146°30'W 146°20'W

70°14'N 70°12'N

EXPLANATION

200x

1947

0 1

Kilometers

3

0 1

Miles

Flaxman Island

146°10'W 146°W

70°12'N 70°10'N

EXPLANATION

200x

1947

0 1

Kilometers 3 0 1

Miles

A

B

D

C

E

Background images courtesy UAF-GINA (http://alaskamapped.org/bdl); includes material © CNES 2011, Distribution Spot Image S.A., France, SICORP, USA, all rights reserved.

Figure 29. Detailed maps of barrier islands in Region 3, Staines River to Sagavanirktok River, north coast of Alaska. Note rotation 

from north for figures A and B. 

Flaxman Island

Flaxman Island, the easternmost island in the barrier chain, 

was mapped as a single, 11 km long island on 1947 T-sheets. 

By 2001, the island was apparently breached and segmented 

into multiple islands (fig. 29E). The eastern 3.5 km of Flaxman 

Island is a well-vegetated, remnant tundra island with a low-lying, 

recurved spit at the extreme eastern end. Bluffs along the tundra 

coast reach over 6 m high in the east and decrease in height to 

the west. Beaches fronting the bluffs are rare and narrow (<5 m 

wide) when present. Thermokarst lakes and high-center polygons 

are common (fig. 24C). At least two artificial ponds and a gravel 

airstrip are visible in the 2006 aerial photography (Gibbs and 

Richmond, 2009). The western 8.5 km of the island chain consists 

of several low-lying (<1.5 m high), unvegetated, narrow spits 

and barrier islands, generally less than 50 m wide. At the western 

end, multiple beach ridges are separated by shallow ponds 

and lagoons. Between 1947 and 2001, the island experienced 

considerable erosion, averaging 150 m retreat along the remnant 

tundra coastline and 180 m landward migration of the low-lying 

barriers. The western quarter of the island prograded on average 

50 m seaward and extended about 1.5 km to the west. DSAS 

generated shoreline change rates indicate that the open-ocean coast 

of Flaxman Island is dominantly erosional (83 percent of transects) 

averaging -2.3 m/yr and ranging from -10.4 to +1.9 m/yr (table5); 

however, the rate calculations do not account for much of the 

accretion and extension of the island beyond the 1947 footprint. 

The total island area decreased by 375,526 m2 (table 6).
Historical Shoreline Change Analysis 45

Maguire Islands

The Maguire Islands, bound by Mary Sachs Entrance 

on the east and Challenge Entrance on the west, is an 

approximately 15 km long barrier chain including North 

Star, Duchess, Alaska, and Challenge Islands and numerous 

small, unnamed islands. The islands are low-lying (<2 m 

high), unvegetated, and narrow. The Maguire Island chain 

shows a complex pattern of change between 1947 and 

2001, including erosion, accretion, and extension of the 

islands to the east and west (fig. 29D). DSAS calculated 

shoreline change rates indicate that the open-ocean coast of 

the Maguire Islands is erosional (66 percent of transects) 

averaging -1.8 m/yr and ranging from -13.7 to +6.7 m/yr 

(table 5); however, the calculations do not account for much 

of the accretion and extension of the islands due to the lack 

of overlapping shorelines. The total island area increased by 

570,890 m2 (table 6).

Stockton Islands

The Stockton Islands, between Challenge Entrance on the 

east and Newport Entrance on the west, are an approximately 

8 km long barrier chain including Belvedere and Pole Islands 

and numerous unnamed islands and shoals. The islands are lowlying (<2 m high) and mostly unvegetated except for low-lying 

vegetation in topographic lows, and sparse higher vegetation 

near the central, stable part of Pole Island. Between 1947 and 

1997, the Stockton Islands nearly completely migrated landward 

of their 1947 position, with only the central/eastern end of Pole 

Island sharing a similar footprint (fig. 29C). Belvedere Island 

migrated on average 402 m landward, while Pole Island migrated 

landward on average 165 m, but also extended nearly 600 m 

to the east. By 1997, Belvedere and Pole Islands had merged 

into one nearly continuous, 8 km long island, separated by two 

narrow passes. The numerous small islands and shoals south 

of Belvedere Island and within Challenge Entrance share no 

overlapping footprints suggesting the islands migrated landward 

and/or eroded completely and reformed in a new location 

hundreds of meters landward of their 1947 location. Shoreline 

change rates were not calculated for these discontinuous small 

islands and shoals, however, their areas are included in the 

overall area calculation. DSAS calculated shoreline change rates 

indicate that the open-ocean coast of the Stockton Islands is 

dominantly erosional (85 percent of transects) averaging 

-4.6 m/yr and ranging from -11.2 to +6.0 m/yr (table 5); 

however, the calculations do not account for much of the 

accretion and extension of the islands beyond the 1947 footprint. 

The total island area increased by 235,324 m2 (table 6).

McClure Islands

The McClure Islands, the westernmost islands in Region 

3, include Karluk, Jeanette, and Narwhal Islands and several 

unnamed islands between Karluk and Jeanette. By 1997, the 

islands had migrated landward of their 1947 footprint to occupy 

an entirely new footprint, except the western end of Narwhal 

Island which remained generally stable and accreted to the 

west (fig. 29B). Narwhal Island, mapped as one island in 1947, 

segmented into 2 separate islands, and rotated counter-clockwise, 

with the eastern part of the island migrating landward on average 

285 m and extending 675 m to the southwest, and the western 

part of the island remaining stable, prograding, or extending 

about 350 m to the northwest. Jeanette, Karluk, and the unnamed 

islands migrated on average 675 m to the southwest. DSAS 

calculated shoreline change rates indicate that the open-ocean 

coast of the McClure Islands is dominantly erosional (92 percent 

of transects) averaging -6.5 m/yr and ranging from -16.8 to 

+3.5 m/yr; however, the calculations do not account for much of 

the accretion and extension of the islands beyond their original 

footprint, nor the loss of many of the smaller islands between 

Jeanette and Karluk Islands. The total island area decreased by 

48,933 m2 (table 6) between 1947 and 1997.

Tigvariak Islands

The Tigvariak Islands, located just off the mouth of 

the Shaviovik River, include a large tundra remnant island 

with a recurved barrier spit extending about 1.5 km eastward 

to Reliance Point and a detached 2 km long barrier island 

extending west to Lion Point. The barrier spit and island are 

low-lying (<1.5 m high) and generally less than 50 m wide, 

although wider on the east and west ends, respectively. They 

are mostly unvegetated except for low-lying vegetation in 

topographic lows on the western side of the barrier island. The 

larger Tigvariak Island reaches up to 5 m high in the center of 

the island, but is generally less than 3 m high and fronted by 

narrow sand and gravel beaches. An abandoned gravel pad 

is present on the northeast side of the island. The barrier spit 

and open-ocean coast of the tundra island have experienced 

relatively little shoreline change between 1947 and 2006, 

however, the detached barrier island shows a shoreline change 

pattern similar to the barriers offshore, with considerable erosion 

on the east side of the island and deposition, progradation, 

and extension of the western shore (figs. 25 and 28). In order 

to maintain consistency with other National Assessment of 

Shoreline Change products that evaluate rates of shoreline 

change only along exposed open-ocean coastlines, average 

rates of shoreline change for Region 3 include only rates 

calculated along the exposed open-ocean coast of the Tigvariak 

Islands (figs. 23 and 25). Because Tigvariak Island is a major 

geomorphic feature along north coast of Alaska, however, 

shorelines, baselines, transects, and rates of change are included 

in the GIS data base (Gibbs and others, 2015, and historical 

changes are summarized in tables 5 and 6 and figure 30.

The exposed open-ocean coast of the Tigvariak Islands 

are dominantly erosional (86 percent of transects) with an 

average shoreline change rate of -1.1 m/yr and range of 

-7.0 to +2.8 m/yr (table 5). Similar to the other islands in 

this region, the calculations do not account for much of the 

accretion and extension of the islands beyond their original 

footprint (fig. 30; table 5). The total island area decreased by 

188,638 m2 between 1947 and 2006 (table 6).
46 National Assessment of Shoreline Change—Historical Shoreline Changes along the North Coast of Alaska

Lion Point

Reliance

Point

Shaviovik River

Tigvariak Island

147°20'W 147°16'W 147°12'W 147°8'W

70°14'N 70°12'N

EXPLANATION

Shoreline Change Rate (m/yr)

-16.8 to -5.0

-5.0 to -2.0

-2.0 to -0.3

-0.3 to +0.3

+0.3 to +2.0

+2.0 to +5.0

+5.0 to +6.7

Shoreline Position

1940s

2000s

0 0.5 1 KILOMETERS

0 0.5 1 MILES

Background orthoimagery courtesy BP Alaska

Figure 30. Map showing shoreline change rates for the Tigvariak Islands, Region 3, Staines River to Sagavanirktok River, north 

coast of Alaska. Length of line represents shoreline change envelope, or total shoreline change over analysis period, and distance 

between historical shorelines.
Historical Shoreline Change Analysis 47

Figure 31. Map showing color-coded shoreline types within Region 4, Sagavanirktok River to Colville River, north coast of Alaska.

150°30'W 150°W 149°30'W 149°W 148°30'W 148°W 70°40'N 70°30'N 70°20'N

UTM zone 5 UTM zone 6

EXPLANATION

NAD83_UTM_Zone_6 Base image: LANDSATmosaic ns124_mss

0 5 10 KILOMETERS

0 5 10 MILES

Exposed Barrier Island

Exposed Barrier Spit

Exposed Island

Exposed Mainland

Sheltered Mainland

Sagavanirktok River

Gull Island

Argo

Island

Kuparuk River

Point Storkersen

Heald Point

Stump Island

Return Islands

Leavitt Island

Colville

River Delta

Bodfish Island

Midway Islands

Bertoncini Island

Gwydyr Bay

Fawn Creek

Egg Island Back Point

Spy Islands

Prudhoe

Bay

Milne Point

Long Island

Cross Island

Thetis Island Pingok Island

Oliktok

Point

Kalubik

Creek

Jones Islands

Cottle Island

Beechey Point

Simpson Lagoon

Point

McIntyre

Kavearak Point

Ugnuravik

River

Bartlett Island

Sakonowyak

River

Putuligayuk River

 Kuparuk

River Delta

Sagavanirktok

River Delta

Endicott

Causeway

West

Dock 

Prudhoe

Dock 

Reindeer

Island

Beaufort Sea

west east

(4) Sagavanirktok River to Colville River 

Introduction

Region 4 extends approximately 100 km between the 

Sagavanirktok and Colville River Deltas and includes both 

exposed open/barrier coast and sheltered mainland/lagoon coast 

(fig. 31). There is considerable oil and gas related development 

in the region, notably near Oliktok Point and Prudhoe Bay, the 

Prudhoe Dock, and the West Dock causeway which leads to 

the artificial Endicott Island. There are two DEW sites along 

this coast, the former Intermediate DEW site at Point McIntyre, 

which closed in 1963, and the former Auxiliary DEW site and 

current North Warning System Long Range Radar site at Oliktok 

Point. Local fish camps and/or non-oil and gas related structures 

exist near Beechey Point, Milne Point and Oliktok Point. The 

unincorporated community of Deadhorse is located about 12 km 

south of Prudhoe Bay at the end of the James W. Dalton Highway, 

a supply road built to support the Prudhoe Bay oilfields and TransAlaska Pipeline System and the only road connecting the North 

Slope to the rest of Alaska. Development in Deadhorse includes 

the Deadhorse/Prudhoe Bay Airport and numerous support 

facilities for the workers and companies that operate the nearby oil 

fields.

Region 4 is characterized by a chain of barrier islands 

fronting a low- to moderately-high tundra mainland coast. The 

mainland coast extends approximately 95 km from Heald Point, at 

the western side of the Sagavanirktok River Delta, to the eastern 

side of the Colville River Delta. It is segmented by the Kuparuk 

River and Delta, several rivers (Putuligayuk, Sakonowyak, 

Ugnuravik), creeks (Fawn Creek and Kalubik), three unnamed 

rivers between Beechey and Milne Points, Prudhoe Dock, and the 

West Dock causeway. The coast of Prudhoe Bay, between Heald 

Point and Point McIntyre, is somewhat exposed to open-ocean 

energy conditions, although Cross and Reindeer-Midway Islands, 

located about 15 km offshore, and the West Dock causeway, may 

dampen some incident wave energy. Between Point McIntyre 

and the Colville River, the mainland coast is separated from the 

barrier island chain by Gwydyr Bay and Simpson Lagoon. The 

mainland coast is predominantly low- to moderately-high bluffs 

(<3 m high) and low-lying landscape (<2 m high) associated 
48 National Assessment of Shoreline Change—Historical Shoreline Changes along the North Coast of Alaska

with tapped thermokarst lakes and adjacent rivers, creeks, and 

drainages. Relatively higher bluffs (up to 5 m high) are found only 

near Heald Point on the eastern coast of Prudhoe Bay. Beaches 

are generally narrow, when present, but reach up to 30 m wide at 

several locations.

The barrier island coast of Region 4 includes Cross Island 

and the Midway Islands (Argo and Reindeer) located 15–20 km 

north of Prudhoe Bay and an approximately 65 km long, nearly 

continuous barrier island chain that stretches between Stump 

Island and Thetis Island. The island chain trends southeastnorthwest and increases in distance from the mainland from 

east to west, from about 1 km near Stump Island to more 

than 9 km at Thetis Island. Most of the islands are lowlying and unvegetated to sparsely-vegetated, except for the 

remnant-tundra portions of the Jones Islands (Cottle, Bodfish, 

Bertoncini, and Pingok Islands) which are well-vegetated and 

up to 5 m high.

Shoreline change rates were determined using 1947 

T-sheets and a combination of 1997 vector shorelines 

Figure 32. Map showing color-coded shoreline change rates in Region 4, Sagavanirktok River to Colville River, north coast of 

Alaska. Width of line represents shoreline change envelope, or total shoreline change over analysis period, and distance between 

historical shorelines.

(Reindeer/Midway Islands) and 2004, 2006, or 2007 

orthorectified aerial photography (table 2; fig. 4). The region 

crosses two UTM zones (5 and 6). Region 4 is predominantly 

erosional (85 percent of transects) with combined shoreline 

change rates for both the sheltered mainland and exposed openocean barrier island coasts averaging -1.1 m/yr and ranging 

between -14.7 to +7.0 m/yr (fig. 32; table 5). Average rates of 

shoreline change for the mainland coast are half of the barrier 

island coast (-0.8 and -1.6 m/yr, respectively). The highest 

erosion and accretion rates are associated with the migration of 

barrier islands and associated formation and infilling of inlets, 

although much of the change to the barrier island coast is not 

accounted for in the DSAS analysis because of island migration 

beyond the original island footprint. The total surface area of 

the barrier islands decreased by 113,245 m2 between 1947 and 

2007, largely due to the considerable loss of land at Pingok 

Island (table 7). A detailed discussion of the geomorphology 

and shoreline change history for the mainland and barrier 

coasts follows.

150°30'W 150°W 149°30'W 149°W 148°30'W 148°W 70°40'N 70°30'N 70°20'N

UTM zone 5 UTM zone 6

EXPLANATION

NAD83_UTM_Zone_6 Base image: LANDSATmosaic ns124_mss

0 5 10 KILOMETERS

0 5 10 MILES

Shoreline Change Rates (m/yr)

-14.7 to -5.0

-5.0 to -2.0

-2.0 to -0.3

-0.3 to +0.3

+0.3 to +2.0

+2.0 to +5.0

+5.0 to +7.0

Sagavanirktok River

Gull Island

Argo

Island

Kuparuk River

Point Storkersen

Heald Point

Stump Island

Return Islands

Leavitt Island

Colville

River Delta

Bodfish Island

Midway Islands

Bertoncini Island

Gwydyr Bay

Fawn Creek

Egg Island Back Point

Spy Islands

Prudhoe

Bay

Milne Point

Long Island

Cross Island

Thetis Island Pingok Island

Oliktok

Point

Kalubik

Creek

Jones Islands

Cottle Island

Beechey Point

Simpson Lagoon

Point

McIntyre

Kavearak Point

Ugnuravik

River

Bartlett Island

Sakonowyak

River

Putuligayuk River

 Kuparuk

River Delta

Sagavanirktok

River Delta

Endicott

Causeway

West

Dock 

Prudhoe

Dock 

Reindeer

Island

Beaufort Sea

west east
Historical Shoreline Change Analysis 49

Table 7. Total barrier island area in Region 4, Sagavanirktok River to Colville River, north 

coast of Alaska, for each era and total change during analysis period, in square meters.

Island 1940s 2000s 2000s–1940s

Cross Island 622,868 634,507 11,639

Midway (Argo) Islands 35,115 0 -35,115

Midway (Reindeer) Islands 156,010 352,294 196,284

Stump Island 310,055 526,115 216,060

Egg Islands 133,226 102,494 -30,732

East Long Island 323,676 364,676 41,000

West Long Island 659,793 2,742,875 2,083,082

Cottle Island 928,741 0 -928,741

Bodfish Island 521,437 0 -521,437

Bertoncini Island 155,788 0 -155,788

Pingok Island 4,531,796 2,922,684 -1,609,112

Leavitt Island 0 426,882 426,882

Spy Islands 479,330 664,580 185,250

Thetis Island 523,600 531,084 7,484

TOTAL 9,381,435 9,268,190 -113,245

Sheltered Mainland-Lagoon Shoreline Change

The mainland coast of Region 4 is predominantly erosional 

(95 percent of transects), with an average shoreline change rate of 

-0.8 and range between -4.2 and +1.2 m/yr (table 5). The highest 

erosion rates are associated with inundation and loss of low-lying 

land between Milne and Oliktok Points. Notable rates of accretion 

were measured at Heald Point, Prudhoe Dock, and between Milne 

and Oliktok Points, where hardened shorelines were constructed 

to protect or support oil and gas related infrastructure, and on the 

northeastern facing sides of the headlands at Milne and Kavearak 

Points. Lower accretion rates, less than 0.3 m/yr, were measured 

at McIntyre, Beechey and Oliktok Points. Overall, shoreline 

change rates along the mainland coast were relatively consistent 

throughout Region 4 and there is no apparent differences in 

shoreline change rates that can be related to the presence or 

absence of barrier islands, nor their distance offshore of the 

mainland (table 5, fig. 33).

Heald Point to Point McIntyre (Prudhoe Bay)

The coastline of eastern Prudhoe Bay, from Heald Point to 

the Putuligayuk River, is predominantly low-lying coast (<2m) 

with higher bluffs (<5m) near Heald Point. There are relatively 

continuous but narrow (<10 m) beaches between Heald Point to 

about 4 km east of Putuligayuk River, where the land is low-lying 

(<1.5 m high) and fronted discontinuously with very narrow 

(<5 m wide) beaches. Along this low-lying stretch, brown, saltkilled tundra indicative of marine inundation is common. From 

the Putuligayuk River to Point McIntyre, the western Prudhoe 

Bay coastline is predominantly low bluffs (<2 m high) fronted by 

discontinuous, narrow beaches (<5m wide). In some places, the 

gravel pads associated with oil and gas infrastructure is less than 

10 m from the actively eroding shoreline (fig. 34A). Low-lying, 

relatively wide beaches and barrier spits (~30 m wide) comprise 

the coast between West Dock and Point McIntyre (fig. 34B). 

Shoreline change rates along the mainland coast of Prudhoe 

Bay, between Heald Point and Point McIntyre, are dominantly 

erosional (97 percent of transects) with rates averaging -0.8 m/yr 

and ranging from -2.5 to +1.1 m/yr (table 5). The only significant 

accretion (greater than +0.3 m/yr) was measured at Heald 

Point and is associated with the artificially hardened shoreline 

associated with the oil and gas development.

Point McIntyre to Kuparuk River Delta

Between Point McIntyre and the Kuparuk River Delta 

the coast is low-lying (<1.5 m high) with low bluffs fronted by 

narrow (<10 m wide) beaches east of Fawn Creek (fig. 34C) and 

low to moderately-high bluffs (2–3 m high) with relatively wide 

(10–30 m wide) beaches between Fawn Creek and the Kuparuk 

Delta. Shoreline change rates along the mainland coast between 

Point McIntyre and the Kuparuk River Delta are dominantly 

erosional (96 percent of transects) with rates averaging -0.6 m/yr 

and ranging from -3.7 to +0.9 m/yr (figs. 32 and 33; table 5).

Kuparuk River Delta to Milne Point

From the west side of the Kuparuk River Delta to Milne 

Point, the coast is characterized by low-lying bluffs (<3 m) fronted 

by narrow beaches (<10 m wide) and scattered pocket beaches. 

Shoreline change rates along the mainland coast between the 
50 National Assessment of Shoreline Change—Historical Shoreline Changes along the North Coast of Alaska

Figure 33. Top: Graph of shoreline change rates for sheltered mainland-lagoon coast of Region 4, Sagavanirktok River to the Colville 

River, north coast of Alaska. Gray bar is shoreline change rate uncertainty (±0.3 m/yr) for individual transects. Bottom: Map of coast of 

Region 4 indicating distances measured alongshore.

Prudhoe

 Bay

Thetis Island

Oliktok Point

Beechey

Point Point 

McIntyre

Ugnuravik River

Bartlett Island

$

NAD 1983 UTM 6 

10 KILOMETERS

10 MILES

0 5

0 5

0

10

20

30 40

70

50

60

80

90

100

110

Distance alongshore (kilometers)

Rate of change (meters per year)

Accretion Erosion

 110 100 90 80 70 60 50 -5 -2.5 0 2.5 5 40 30 20 10 0 Kuparuk River Delta

Beechey

Point

Oliktok Point

Point McIntyre

Colville River Delta

Milne

Point

Kavearak

Point

Milne Point

Prudhoe Bay

Midway Islands

Cross Island

Jones Islands

Kabulik Creek

Spy Islands

Kuparuk 

River Delta

Putuligayuk

River

Sagavanirktok

River Delta

Colville 

River Delta

Heald Point

Putuligayuk River

West Dock

Fawn Creek

Sakonowyak River

Kevearak Point

Gwydyr

Bay

Simpson Lagoon

Return Islands
Historical Shoreline Change Analysis 51

Figure 34. Aerial photographs showing typical examples of mainland coast of Region 4, Sagavanirktok River to Colville River, north 

coast of Alaska. A, Low-lying, Prudhoe Bay coastline; view to east. Note salt-killed (brown) tundra, thermokarst lakes, gravel pad, and 

oil and gas infrastructure located adjacent to shoreline. B, View from Point McIntyre east toward West Dock causeway. C, Low bluffs 

and perched beaches near Fawn Creek. Note large amount of wood debris on tundra surface indicating inundation or flooding extents. 

Large white container in foreground contains oil spill response supplies. D, The Oliktok Point Distant Early Warning (DEW) station. Note 

shore protection structures fronting the station. (All photographs from 2006; Gibbs and Richmond, 2009).

Kuparuk River Delta and Milne Point are dominantly erosional 

(94 percent of transects) with rates averaging -0.7 m/yr and 

ranging from -2.8 to +1.2 m/yr (table 5). The highest rates of 

shoreline change along this stretch of coast are associated with 

erosion of a deteriorating headland and former thermokarst lake 

near the Kuparuk River and erosion of the western side of the 

unnamed headland between Beechey and Kavearak Point. All 

four headlands along this section of coast show erosion on the 

northwest facing side and beach accretion on the northeastern 

facing sides (figs. 32 and 33).

Milne Point to Oliktok Point

The highest erosion rates along the mainland shoreline of 

Region 4 were measured between Milne Point and Oliktok Point. 

The coast is dominantly erosional (90 percent of transects) with 

shoreline change rates averaging -1.1 m/yr and ranging from -4.2 

to +1.2 m/yr (table 5). This section of coast is characterized by low 

bluffs (<2 m high) with narrow (<10 m wide) beach and low-lying 

(<1.5 m), tapped thermokarst lake shorelines. Similar to the coastal 

reach between Kuparuk River Delta and Milne Point, erosion rates 

are relatively higher on the northwest-facing side of the headlands 

compared to the northeast-facing sides (figs. 32 and 33). Simpson 

Lagoon is relatively wider and the fronting barrier islands (Leavitt 

and Spy Islands) somewhat further offshore and less continuous 

than to the east. An oil and gas facility on the headland between 

Milne and Oliktok Points shows net accretion, although this may 

be the result of emplacement of a gravel pad and shore protection 

structures (fig. 34D).

Oliktok Point to Colville River Delta

The mainland coast between Oliktok Point and the Colville 

River Delta trends NE-SW and is characterized by low to 

moderately-high bluffs (<3 m high) segmented by drainages and 

fronted by relatively wide, continuous beaches (10–30 m wide). 
52 National Assessment of Shoreline Change—Historical Shoreline Changes along the North Coast of Alaska

Thetis Island is located about 9 km offshore to the northwest. 

Shoreline change rates along this section are dominantly erosional 

(98 percent of transects) with rates averaging -0.8 m/yr and ranging 

from -1.9 to +0.7 m/yr (table 5). Erosion rates are relatively 

uniform along this section of coast regardless of whether the back 

beach is relatively high tundra bluffs or low-lying land associated 

with thermokarst lakes and drainages.

Exposed Open-Ocean Shoreline Change

The exposed open-ocean coast of Region 4, comprised 

entirely of barrier islands, is predominantly erosional (66 percent 

of transects), averaging -1.6 m/yr and ranging between -14.7 and 

+7.0 m/yr (figs. 32 and 35; table 5). The highest rates of erosion 

are associated with the formation of inlets, particularly on the 

east and west ends of Pingok Island, and the southwesterly or 

landward migration of the islands, particularly Reindeer, Long, 

Stump, and Thetis Islands. The total barrier island area decreased 

by 113,245 m2 during the study period, although individual 

islands show considerably different patterns of change (table 7). 

Differences in the geology and morphology of the barrier islands 

within Region 4 result in a complex pattern of shoreline changes 

that are discussed in detail below.

Cross Island

Cross Island, the easternmost island in the region, is lowlying (<2 m high) except for a 5-m high gravel pad built on the 

northwestern end of the island, and ranges in width between 50 

and 300 m. The island is a popular location for whaling activities 

and there are also several cabins and structures located on the 

northwest end of the island. The island is mostly unvegetated 

except for some low-lying vegetation in the topographic lows 

on the northwest part of the island (figs. 36A and 36B). Between 

1947 and 2006, Cross Island merged from two separate islands 

(Bartlett and Cross) into one continuous island, nearly 5 km 

in length, and increased in area by 11,639 m2 (table 7). The 

Long Island Thetis Island

Pingok Island

Oliktok 

Point

Beechey

Point

Midway Islands

Bartlett Island

$

NAD 1983 UTM 6 

10 KILOMETERS

10 MILES

0

0 5

0 20

40

50 60

70 80

90

100

Distance alongshore (kilometers)

Rate of change (meters per year)

Accretion Erosion

 110 100 90 80 70 60 50 -15 -10 -5 0 5 10 15 40 30 20 10 0

Midway

 Islands

Thetis Island Pingok Island

5

Long Island

Stump Island

Milne

Point

Kabulik Creek

Spy Islands

Spy Islands

Jones Islands

Jones Islands

Cottle Island

Cottle Island

Stump Island

Egg Island

Egg Island

Cross Island

Cross Island

Bartlett Island

Prudhoe

 Bay

Point 

McIntyre

Kuparuk 

River Delta

Putuligayuk

River

Sagavanirktok

River Delta

Colville 

River Delta

Leavitt Island

Leavitt

Island

Gwydyr Bay

Simpson Lagoon

Reindeer

Island Argo

Island Return Islands

Return Islands

west east

Figure 35. Top: Graph of shoreline change rates for exposed open-ocean coast of Region 4, Sagavanirktok River to Colville River, north 

coast of Alaska. Gray bar is shoreline change rate uncertainty (±0.3 m/yr) for individual transects. Bottom: Map of coast of Region 4 

indicating distances measured alongshore.
Historical Shoreline Change Analysis 53

Figure 36. Aerial photographs showing typical examples of the barrier island coast of Region 4, Sagavanirktok River to Colville River, 

north coast of Alaska. A, Bowhead whale bones at Cross Island. Note vegetation in low-lying areas, wood wrack, and steep scarp 

fronting open-ocean coastline. B, Cross Island, showing low-lying vegetation in back-barrier environment. C, Pingok Island, a remnant 

tundra island, with drained thermokarst lakes and thaw slump deposits on rapidly eroding eastern end of island. D, Spy Islands. Note 

well-defined scarp, wood debris on higher parts of island, and vegetation only in topographic lows. (All photographs from 2006; Gibbs 

and Richmond, 2009).

northwestern part of Cross Island prograded about 200 m to the 

north and extended about 250 m to the west while the southern 

end extended nearly 2 km to the south west and migrated 

landward approximately 400 m to the southwest. The open-ocean 

shorelines of Cross Island are erosional (81 percent of transects) 

with shoreline change rates between 1947 and 2006 averaging 

-4.7 m/yr and ranging from -14.4 to +4.0 m/yr (table 5), although 

the DSAS analysis does not account for the total accretion of land 

associated with the progradation and extension of the island.

Midway Islands

The Midway Islands, including Argo and Reindeer Islands, 

are low-lying (<1 m high), predominantly unvegetated islands 

with little wood wrack or debris deposits. A shoreline was not 

delineated for Argo Island in the 1997 dataset used in this area, 

and thus, shoreline change rates could not be determined for 

the island. An island was photographed in 2006 by Gibbs and 

Richmond (2009) about 700 m southwest Argo Island’s 1947 

footprint, suggesting the island does exist, but has migrated 

further than the extent of existing datasets. The Midway Islands, 

mapped as a single Reindeer Island in 1947, migrated up to 

up to 500 m (mean 329 m) to the southwest, extended about 

1 km to the west, split into two islands (Reindeer and Argo), 

and increased in area by 161,168 m2 (table 7). There is only a 

very small area of overlapping area of Reindeer Island in the 

1947 and 2006 island footprints. The open-ocean shorelines of 

Reindeer Island are entirely erosional (100 percent of transects) 

with shoreline change rates averaging -6.6 m/yr and ranging 

from -10.0 to -2.4 m/yr (table 5), although the DSAS analysis 

does not account for the accretion of land associated with the 

westward extension of the island.

Stump, Egg, and Eastern Long Islands

Between Stump Island and the eastern part of Long Island 

where the orientation of the coast changes from northwestsoutheast to east-west, the barrier islands are narrow (< 100 m 

wide), low lying (<2 m high), and unvegetated. Between 1947 

and 2007, Stump Island extended nearly 2 km to the northwest, 
54 National Assessment of Shoreline Change—Historical Shoreline Changes along the North Coast of Alaska

about 900 km to the southeast, and the central portion of the island 

migrated 150 m to the southwest. During the same time period, the 

Egg Islands segmented into numerous smaller islands, extended 

about 600 km to the west and migrated as much as 554 m to the 

southwest. The eastern part of Long Island segmented into at least 

four separate islands and portions migrated landward over 500 

m. Some of the loss of the Egg Islands likely is responsible for a 

portion of the westward extension of Stump Island and eastward 

extension of Long Island. Shoreline change rates for this eastern 

part of the barrier chain average -1.8 m/yr and range between -9.2 

and +7.0 m/yr (table 5), although DSAS rates do not include the 

extension of Stump nor eastern Long Island nor the loss of most 

of the Egg Islands (fig. 37B). The total area of Stump, Egg, and 

eastern Long Island increased by 226,328 m2 between 1947 and 

2007 (table 7).

West Long Island to Leavitt Island

From the eastern part of Long Island where the orientation of 

the coast changes from northwest-southeast to east-west to Leavitt 

Island, the barrier islands show a much more stable to accretionary 

shoreline change pattern during the study period compared to the 

islands to the east and west in Region 4 (fig. 37C). Long, Cottle, 

Bodfish, and Bertoncini Islands, mapped as four discrete islands 

on the 1947 T-sheets, merged into a single, 22 km long island 

connected by low-lying, narrow, barrier spits by 2004. Pingok 

Island, mapped as a 13 km long island in 1947, was breached at 

both ends, forming inlets resulting in considerable erosion and 

loss of land on the eastern end of Pingok Island and the formation 

of Leavitt Island in the west. The former Cottle, Bodfish, and 

Bertoncini Islands are recognizable as remnant tundra islands that 

are relatively wide (>100 m) and reach nearly 5 m high. These are 

well-vegetated and the shoreline is typified by low bluffs fronted 

by beaches. The barriers between the remnant tundra islands and 

west of Bertoncini Island are generally narrow (<100 m) and lowlying (<2 m), except along western Long Island where the seaward 

beach berms reach up to 3 m high and the maximum width of 

the island is about 300 m. These barrier islands are unvegetated, 

except along the historically stable areas of the island chain 

where some low-lying vegetation and wood debris deposits were 

observed. Pingok Island is a relatively large (8 km long in 2004), 

well-vegetated, tundra remnant island with a narrow, unvegetated, 

recurved western end. The eastern quarter of the island is 

characterized by high bluffs (up to 5 m high) fronted by narrow 

to no beach deposits, and tapped thermokarst lake shorelines (fig. 

36C). The western three-quarters of the island includes low to high 

bluffs (generally less than 3 m) fronted by relatively wide beach 

deposits (up to 100 m wide). The eastern and western portions of 

Pingok Island experienced considerable erosion between 1947 

and 2004 while the central portion remained stable or accreted. 

In contrast to many of the other barrier islands in the study area, 

Pingok Island also experienced extensive erosion along the lagoon 

coast. In the 2004 imagery, Leavitt Island is just over 4 km long 

and recurved at both ends. The island is low-lying (<2 m), narrow 

(<200 m), and mostly unvegetated. The position and width of 

the central portion of the island remained relatively stable during 

the study period, whereas the west end of the island extended 

westward about 1.5 km and the eastern end migrated over 200 m 

landward in response to the formation of the inlet between Leavitt 

and Pingok Island. Some low-lying vegetation and wood debris 

were observed in the stable, central portion of the island.

Aside from the accretion of new land between Long, Cottle, 

Bodfish and Bertoncini Islands, the westward extension of 

Bertoncini Island and Leavitt Islands, and the erosion associated 

with the formation of the inlets bounding Pingok Island, 

the barrier island chain from western Long Island to Leavitt 

Island experienced little change in shoreline position or barrier 

morphology between 1947 and 2004, with generally less than 

100 m of change in shoreline position. Shoreline change rates 

along the exposed open-ocean coast of the barrier islands between 

western Long Island and Leavitt Island average -0.7 m/yr and 

range from -14.7 to +4.1 m/yr (table 5), although much of the 

accretion of land is not accounted for in the DSAS analysis due to 

the lack of overlapping shorelines. The total island area between 

western Long Island and Leavitt Island decreased by 705,114 m2

between 1947 and 2007, primarily as a result of the considerable 

loss of Pingok Island land area (table 7).

Spy Islands

The Spy Islands (two islands in 2004) are approximately 

7 km long and low-lying, less than 2 m high. The islands are 

unvegetated except for low-lying vegetation near the stable and 

accreting area at the eastern and western extents of the island, 

where wood debris is also present (fig. 36D). The island varies 

in width between 15 and 350 m, and is widest on the western 

end. Between 1947 and 2004, the Spy Islands (one island in 

1947) segmented into two islands, extended about 1200 m to the 

southwest and 270 m to the southeast. The central portion of the 

island migrated 224 m landward (to the southwest) and the western 

end accreted approximately 245 m. Shoreline change rates for the 

open-ocean coast of the Spy Islands average -1.4 m/yr and range 

from -4.0 to +4.3 m/yr (table 5), although the DSAS rates do not 

account for the extension of the island to the west. The total island 

area increased by 185,250 m2 between 1947 and 2007 table 7).

Thetis Island

Thetis Island is approximately 6 km long and low-lying, 

generally less than 2 m high, although a gravel pad at the western 

end increases the maximum island elevation to approximately 

3 m high. The island is unvegetated and varies in width between 

25 and 275 m and is widest on the western end. Between 1947 

and 2004, the two Thetis Islands mapped in 1947 merged into a 

single island. The island extended 800 m to the west and 730 m 

to south. The northwest portion of the island migrated landward 

nearly 800 m and the southeastern portion of the island extended 

nearly 300 to the northeast. Shoreline change rates for the 

open-ocean coast of Thetis Island average -1.8 m/yr and range 

from -6.6 to +4.1 m/yr (table 5), although the DSAS rates do not 

account for the extension of the island to the west and south. The 

total island area increased by 7,484 m2 between 1947 and 2007 

(table 7).
Historical Shoreline Change Analysis 55

Figure 37. Detailed maps showing shoreline change to the barrier island chain in Region 4, Sagavanirktok River to Colville River, 

north coast of Alaska. A, All barrier islands in Region 4 showing the change in island footprint between 1947 and 2006/2007. B, Stump 

Island to west Long Island. C, West Long Island to Leavitt Island. Note deviation from north of the maps in figures B and C.

Stump Island

Thetis Island

Kalubik Creek Return Islands

Reindeer Island

Point Storkersen

Bertoncini Island

150°W 149°30'W 149°W 148°30'W 148°W

70°35'N 70°30'N 70°25'N

Gwydyr Bay

Fawn Creek

Egg Island

Back Point

Spy Islands

Milne Point

Long Island

Argo Island

Cross Island

Pingok Island

Oliktok Point

Kuparuk River

Jones Islands

Cottle Island

Beechey Point

Simpson Lagoon

Point McIntyre

Midway Islands

Leavitt Island

Kavearak Point

Bodfish Island

Ugnuravik River

Bartlett Island

Sakonowyak River

Kuparuk River Delta

west east

EXPLANATION

200x

1947

0 5

Kilometers

0 5 3 Miles

Gwydyr Bay

Fawn Creek

Egg Island

Back Point

Long Island

Stump Island

Kuparuk River

Return Islands

Point McIntyre

Sakonowyak River

Point Storkersen

west east 

149°0'W 148°40'W

70°28'N 70°30'N

EXPLANATION

2007

1947

0 5

Kilometers

3

0 5

Miles

Bertoncini Island

149°40'W 149°20'W 149°W

70°34'N 70°36'N 70°32'N

Gwydyr Bay Back Point

Milne Point

Long Island

Pingok Island

Jones Islands

Cottle Island

Beechey Point

Simpson Lagoon Return Islands

Leavitt Island

Kavearak Point

Bodfish Island

EXPLANATION

2007

1947

0 5

Kilometers

3

0 5

Miles

west east

Background orthoimagery courtesy BP Alaska and ConocoPhillips

Background orthoimagery courtesy BP Alaska and ConocoPhillips

Base image: LANDSATmosaic ns124_mss

B

C

A
56 National Assessment of Shoreline Change—Historical Shoreline Changes along the North Coast of Alaska

(5) Colville River to Cape Halkett

Introduction

Region 5 extends approximately 100 km along the west 

coast of Harrison Bay between the Tingmeachsiovik River on 

the western side of the Colville River Delta and Cape Halkett. 

The region is part of both the NPR-A and TLSA. The coast 

is undeveloped aside from the Kogru Intermediate DEW site, 

which closed in 1963 and was located on the Kogru River and 

about 2 km inland from the open coast. There are no permanent 

villages.

The coast of Region 5 faces northeast, trends northeast 

to southwest, and is relatively sheltered from dominant wave 

energy from the northwest. Several, small remnant tundra islands 

are present south of Atigaru Point, south of Garry Creek, and 

the larger Eskimo Islands near the mouth of the Kogru River. 

The remaining mainland coast is segmented by two large rivers 

(Kalikpik and Kogru), Garry Creek, and a large embayment about 

half-way between Garry Creek and Cape Halkett (fig. 38). The 

coastal plain is dominated by thermokarst lakes, but is markedly 

different north and south of the Kogru River, with relatively small 

thermokarst lakes south of the Kogru River and larger, elongated 

(northwest-southeast) lakes north of the Kogru River. InSAR 

elevation data shows a distinct change in the regional coastal 

slope around the Kogru River, where south of the river, elevations 

reach up to 15 m within 4 km of the coast compared to a distance 

greater than 8 km to the north (fig. 39). Beaches along this section 

of coast are primarily associated with tapped thermokarst lakes 

and more rarely fronting tundra bluffs, where they are typically 

narrow (<10 m wide), when present.

Shoreline change rates were calculated using 1947 

T-sheets and 2002 DOQQ imagery (table 2; fig. 4). Shoreline 

change rates were not calculated for the remnant tundra 

islands. All rates presented are for the exposed, open-ocean, 

mainland coast. The coast of Region 5 is predominantly 

erosional (92 percent of transects) and has some of the lowest 

rates of shoreline change in the study area, with shoreline 

Figure 38. Map showing color-coded shoreline types within Region 5, Colville River to Cape Halkett, north coast of Alaska.

152°30'W 152°W 151°30'W 151°W

70°40'N 70°30'N

Background image USGS DOQQ (http://earthexplorer.usgs.gov)

EXPLANATION

0 5 10 KILOMETERS

0 5 10MILES

Exposed Barrier Island

Exposed Barrier Spit

Exposed Island

Exposed Mainland

Sheltered Mainland

Kogru River

Garry Creek

Harrison Bay

Cape Halkett

Atigaru Point

Saktuina Point

Kalikpik River

Tingmeachsiovik

River

Eskimo Islands

Colville

River Delta

Kogru 

DEW site

Beaufort Sea

embayment
Historical Shoreline Change Analysis 57

Figure 39. Coastal elevation map derived from Interferometric Synthetic Aperture Radar data for parts of Regions 5–9, Colville River 

to Icy Cape, north coast of Alaska. Note distinct differences in elevation of coastal plain north and south of Kogru River and along 

Chukchi Sea coast.

159°W 158°W 157°W 156°W 155°W 154°W 153°W 152°W 151°W 150°W

71°40'N 71°20'N 71°N 70°40'N 70°20'N

EXPLANATION

Elevation (meters)

< 0

0 - 2

2 - 3

3 - 5

5 - 10

10 - 20

20 - 30

30 - 40

40 - 50

50 - 100

0 20 KILOMETERS

0 20 MILES

Pt. Barrow

Peard Bay

Dease

Inlet

Elson Lagoon

Colville 

Kogru River River Delta

Harrison Bay

Cape

Halkett

Drew

Smith Point

Bay

Teshekpuk Lake

change rates averaging -1.1 m/yr and ranging from -9.6 

to +5.0 m/yr (figs. 40 and 41; table 5). Erosion rates are 

generally higher west of Atigaru Point with highest erosion 

rates associated with an eroded spit about 5 km north of 

Garry Creek (figs. 40 and 41). There are only a few areas of 

significant accretion in the region, including the spit at the 

embayment between Garry Creek and Cape Halkett, just east 

of Garry Creek, at the Kalikpik River, and individual transects 

between the Tingmeachsiovik River and Atigaru Point.

Shoreline morphology, geology, and patterns of shoreline 

change are considerably different north and south of the Kogru 

River. Whereas both sections are predominantly erosional, average 

erosion rates are over 3 times higher north of the Kogru River 

compared to south (-1.7 and -0.5 m/yr, respectively; table 5). The 

bluffs between the Tingmeachsiovik River and the Kogru River 

appear in aerial photographs to be sandier (lighter color) and no 

visible ice was observed in the bluffs, suggesting a low ice content, 

which may be partly responsible for the observed lower erosion 

rates.

Exposed Open-Ocean Shoreline Change

Tingmeachsiovik River to Kalikpik River

At the southeastern boundary of Region 5, between the 

Tingmeachsiovik and Kalikpik Rivers, the coast is dominated 

by low-lying, vegetated marsh with no beaches, that transitions 

to moderately-high to high bluffs (3–10 m high) fronted by 

narrow beaches (< 10 m wide) approaching the Kalikpik River 

(figs. 42A and 42B). Shoreline change rates for this stretch 

are predominantly erosional (93 percent of transects; average, 

-0.7 m/yr; range, -4.7 to +1.1 m/yr) (table 5), with the highest 

rates measured in the low-lying marsh areas adjacent to the 

Tingmeachsiovik River.

Kalikpik River to Atigaru Point

From the Kalikpik River to Atigaru Point the coast is 

dominantly low-lying tundra bluffs, generally less than 2 m high, 

but reaching up to 6 m high in places. Beaches are rare, except 

fronting the higher bluffs. The coastline here trends southwest 

to northeast, and is sheltered from nearly all incident wave 

energy, however, for this analysis it is still considered open-ocean 

mainland coast because there are no protective barrier islands. 

The reach is erosional (81 percent of transects) with an average 

shoreline change rate of -0.2 m/yr (range, -1.6 to +3.8 m/yr) 

(table 5), which is below the analytical uncertainty on individual 

transects. This reach has some of the lowest shoreline change rates 

measured in the study area.

Atigaru Point to Kogru River

Between Atigaru Point and the Kogru River, the coast is 

dominated by high bluffs (<5 m high) fronted by relatively 

wide beaches (10–20 m). In the 2002 imagery, the lowlying (2 m high) headland near Atigaru Point is separated 
58 National Assessment of Shoreline Change—Historical Shoreline Changes along the North Coast of Alaska

Figure 40. Map showing the color-coded shoreline change rates in Region 5, Colville River to Cape Halkett, north coast of Alaska. 

Width of line represents shoreline change envelope, or total shoreline change over analysis period, and distance between historical 

shorelines.

152°30'W 152°W 151°30'W 151°W

70°40'N 70°30'N

Background image USGS DOQQ (http://earthexplorer.usgs.gov)

EXPLANATION

0 5 10 KILOMETERS

0 5 10MILES

Shoreline Change Rates (m/yr)

-9.6 to -5.0

-5.0 to -2.0

-2.0 to -0.3

-0.3 to +0.3

+0.3 to +2.0

+2.0 to +5.0

+5.0 to +5.1

Kogru River

Garry Creek

Harrison Bay

Cape Halkett

Atigaru Point

Saktuina Point

Kalikpik River

Tingmeachsiovik

River

Eskimo Islands

Colville

River Delta

Kogru 

DEW site

Beaufort Sea

embayment
Historical Shoreline Change Analysis 59

Figure 41. Top: Graph of shoreline change rates for exposed open-ocean coast of Region 5, Colville River to Cape Halkett, north coast 

of Alaska. Gray bar is shoreline change rate uncertainty (±0.3 m/yr) for individual transects. Bottom: Map of coast of Region 5 indicating 

distances measured alongshore.

Garry Creek

Harrison Bay

Cape Halkett

Atigaru Point

Saktuina

Point

Kalikpik River

Eskimo Islands

Tingmeachsiovik

River $

NAD 1983 UTM 5 

10 KILOMETERS

10 MILES

0 5

0 5

0

10

20 30

40

50

70 60

80

90

100

110

Distance alongshore (kilometers)

Rate of change (meters per year)

Accretion Erosion

 110 100 90 80 70 60 50 -10 -5 0 5 10 40 30 20 10 0 Kalikpik River

Atigaru Point

Cape Halkett

Harrison Bay

Colville River

Delta

Saktuina Point

Kogru

River

Garry Creek Kogru River
60 National Assessment of Shoreline Change—Historical Shoreline Changes along the North Coast of Alaska

Figure 42. Aerial photographs showing typical examples of the coast of Region 5, Colville River to Cape Halkett, north coast of Alaska. 

A, Low lying marsh/tundra deposits near Tingmeachsiovik River. B, High bluffs (8 m high) near the Kalikpik River. C, Inundated tundra 

with an irregular pattern near Garry Creek. D, One of the few areas of deposition in Region 5, an accretional spit deposited on northern 

side of embayment between Garry Creek and Cape Halkett. This entire feature accreted since 1947. (Photographs A,B,C taken in 2006, 

and D taken in 2009; Gibbs and Richmond, 2009, 2010).

from the adjacent mainland by a narrow channel, but for 

this analysis it is still considered open-ocean mainland 

coast. The remnant tundra Eskimo Islands are just offshore 

the mouth of the Kogru River and provide some protection 

from incident wave energy to the adjacent mainland. This 

reach is dominantly erosional (98 percent of transects) with 

an average shoreline change rate of -0.8 m/yr and a range 

of -3.1 to +0.1 m/yr (table 5),with the highest erosion rates 

measured near Atigaru Point.

Kogru River to Cape Halkett

North of the Kogru River, from Saktuina Point to about 

5 km southwest of Garry Creek, the coast is characterized 

by relatively high bluffs (<5 m high) and narrow beaches 

(<10 m wide). Segregated ice layers can be seen in the bluff 

faces, in contrast to the bluffs to the south and east (Gibbs and 

Richmond, 2009, 2010). From about 5 km southwest of Garry 

Creek and continuing north to Cape Halkett, the coast comprises 

numerous low-lying (< 1 m), tapped thermokarst lakes, fronted 

by narrow beaches, and few moderately-high bluffs (<3m high). 

Discontinuous beaches fronting the bluffs are typical. There 

are well-developed ice-wedge polygons in the tundra at several 

places along this section of coast. North of Garry Creek, there 

is an interesting form of patterned tundra observed only in this 

area, very low lying (< ~2 m) inundated and irregular tundra 

surface intermittently fronted by narrow fine-grained beaches 

(fig. 42C). The reach is dominantly erosional (94 percent of 

transects) with an average shoreline change rate of -1.7 m/yr 

and a range of -9.6 to +5.0 m/yr (table 5).

The highest average (and total) erosion rates (100 percent 

of transects) in this region were measured in the section 

between Garry Creek and the embayment one-half way 

between Garry Creek and Cape Halkett (average, -2.7; range, 

-9.6 to -0.3 m/yr) associated with an eroded spit. The highest 

accretion rates (up to +5.0 m/yr) were measured between the 

embayment and Cape Halkett, associated with an accreted spit 

(table 5; figs. 41 and 42D).
Historical Shoreline Change Analysis 61

Figure 43. Map showing color-coded shoreline types within Region 6, Cape Halkett to Drew Point, north coast of Alaska.

(6) Cape Halkett to Drew Point 

Introduction

Region 6 extends approximately 70 km between Cape 

Halkett and Drew Point and includes some of the most rapidly 

eroding coastline in the world (Reimnitz and others, 1985, 

1988; Mars and Houseknecht, 2007; Jones and others, 2008, 

2009a and b). The coast is within the NPR-A and marks the 

seaward boundary of the Teshekpuk Lake Special Area. The 

region is undeveloped and uninhabited aside from the Lonely 

DEW site that was deactivated in 1990 and closed in 2007. 

Cleanup and site remediation is ongoing. There are also 

numerous oil and gas exploration wells along this coast that 

are threatened by coastal erosion.

This coastal stretch trends nearly east to west and includes 

primarily exposed mainland coast but also the sheltered mainland 

coast of Pogik Bay, an exposed barrier island fronting Pogik Bay, 

and a sheltered remnant tundra island between the two, hereafter 

referred to here as Pogik Island (fig. 43). The coastal plain along 

this stretch of coast is dominated by large, elongated thermokarst 

lakes, with much of the land surface affected by thermokarst 

lake processes (Hinkel and others, 2005). The coast is generally 

very low-lying (<3 m) except for several short segments of 

higher coastal bluffs between Cape Halkett and Pitt Point, and a 

relatively continuous stretch between McLeod and Drew Points, 

where coastal bluffs reach up to 6 m high (figs. 39, 44A and 44F). 

Coastline features also include unvegetated, recently tapped 

thermokarst lakes, vegetated former lake basins, and vegetated 

tundra uplands not affected by thermokarst lake activity (Jones and 

others, 2009a) (fig. 44). Much of the region is vulnerable to coastal 

inundation as evidenced by the presence of brown, salt-killed 

tundra and wood wrack deposited far inland (fig. 44D). Beach 

and barrier spit deposits are relatively common along this stretch 

of coast but tend to be low-lying and laterally discontinuous. 

There are many stretches of coast with actively eroding bluffs 

fronted by little or no beaches. Pogik Bay appears to be a remnant 

tapped thermokarst lake with both tundra and barrier islands at the 

entrance to the bay.

Shoreline change rates were calculated using 1947 

T-sheets and 2002 DOQQ imagery (table 2; fig. 4). Numerous 

small shoals and barrier islands present between Pogik Bay 

and Cape Halkett were not considered part of the primary 

EXPLANATION

Background image USGS DOQQ (htpp://earthexplorer.gov)

0 5 KILOMETERS

0 5 MILES

Exposed Barrier Island

Exposed Barrier Spit

Exposed Island

Exposed Mainland

Sheltered Mainland

Pogik

Bay

Pitt Point

Smith River

Drew Point

Boat Creek

Pogik Point Kokruagarok

McLeod Point

Cape

Halkett

Cameron Point

Avatanak Bight

Pogik

Island

Kolovik

Lonely DEW

154°W 153°30'W 153°W 152°30'W

71°N 70°50'N
62 National Assessment of Shoreline Change—Historical Shoreline Changes along the North Coast of Alaska

Figure 44. Aerial photographs showing typical examples of coast of Region 6, Cape Halkett to Drew Point, northern Alaska. A, 

Overview photograph of Drew Point showing about 6-m high bluffs, tundra upland and vegetated former lake basin, view to the east. 

B, Patterned ground near Cape Halkett, view to southwest. C, Recently tapped thermokarst lake west of Lonely, view to south. D, 

Degrading polygonal tundra showing evidence of inundation of low-lying ground including brown, salt-killed tundra and overwash of 

sediments, and wood debris just east of Cameron Point, view to south. E, Partially vegetated tapped lake, view to south. F, High bluffs 

near McLeod Point. Note high ice content in bluffs, themoerosional niche at base of bluffs, overhanging tundra, and lack of a fronting 

beach. (Photographs A,B,D,E,F taken in 2006, and C taken in 2009; from Gibbs and Richmond, 2009, 2010).
Historical Shoreline Change Analysis 63

shoreline and were excluded from the analysis. In order to 

maintain consistency in this study and evaluating only exposed 

open-ocean and sheltered mainland-lagoon shorelines, 

Pogik Island was also not included in average shoreline 

change rate calculations presented here, however, shorelines, 

baselines, and transects are included in the accompanying GIS 

report (Gibbs and others, 2015) and historical changes are 

summarized in table 5.

The coast of Region 6 is predominantly erosional (90 

percent of transects) with combined shoreline change rates for 

both the exposed open-ocean and sheltered shorelines averaging 

-6.3 m/yr. The maximum erosion (-18.6 m/yr) and accretion 

(+10.9 m/yr) rates within the entire study area were measured 

within Region 6 (fig. 45; table 5). The average shoreline change 

rate along exposed open-ocean shorelines (mainland coast and 

barrier island) is considerably higher (-7.1 m/yr) compared to 

the sheltered shorelines of Pogik Bay (-0.5 m/yr) or Pogik Island 

(-0.3 m/yr) (table 5).

Sheltered Coast Shoreline Change

The sheltered shorelines in Region 6 along the mainland 

coast of Pogik Bay are overall erosional (62 percent of 

transects) with shoreline change rates averaging -0.5 m/yr and 

ranging between -5.7 and +10.9 m/yr (table 5). The highest 

rates of accretion in the study area were measured on the 

northwest coast of Pogik Bay, where the shoreline prograded 

nearly 600 m between 1947 and 2002 (figs. 45 and 46).

Pogik Island eroded along both the north and south 

coasts of the central part of the island and the southeast tip 

remained relatively stable. The apparent accretion on the 

northeast side of the island may reflect true aggradation of 

the mudflats mapped in the 1947 T-sheets, but may also be 

a result of defining the boundary of intertidal to subtidal 

lands as supratidal deposits when digitizing the shoreline, 

which is certainly possible along this very low-lying coastal 

environment.

Figure 45. Map showing the color-coded shoreline change rates in Region 6, Cape Halkett to Drew Point, north coast of Alaska. 

Width of line represents shoreline change envelope, or total shoreline change over analysis period, and distance between historical 

shorelines.

EXPLANATION

Background image USGS DOQQ (htpp://earthexplorer.gov)

0 5 KILOMETERS

0 5 MILES

Shoreline Change Rates (m/yr)

-18.6 to -5.0

-5.0 to -2.0

-2.0 to -0.3

-0.3 to +0.3

+0.3 to +2.0

+2.0 to +5.0

+5.0 to +10.9

Pogik

Bay

Pitt Point

Smith River

Drew Point

Boat Creek

Pogik Point Kokruagarok

McLeod Point

Cape

Halkett

Cameron Point

Avatanak Bight

Pogik

Island

Kolovik

Lonely DEW

154°W 153°30'W 153°W 152°30'W

71°N 70°50'N
64 National Assessment of Shoreline Change—Historical Shoreline Changes along the North Coast of Alaska

Figure 46. Maps and graphs showing shoreline change rates for Pogik Bay and neighboring coastline within Region 6, Cape Halkett to 

Drew Point, northern Alaska. A, Map showing the color-coded shoreline change rates and shoreline change envelope, or total shoreline 

change over analysis period for exposed and sheltered coastlines. Accretion measured at northwest part of Pogik Bay (>10.5 m/yr) is 

the highest measured in the study area. B, Plot of shoreline change rates on Pogik Island, and C, within Pogik Bay. Gray bar is shoreline 

change rate uncertainty (±0.3 m/yr) for individual transects. D, Map of coast of Pogik Bay indicating distances measured alongshore in 

C and D.

NAD 1983 UTM 5 

Pogik Bay

Pogik Point

Pogik Island

$

0 1 2 KILOMETERS

0 1 2 MILES

0

2

4

0

2

4

6

6

8

10

Pogik Bay

Pogik Point

152°55'W 152°50'W 152°45'W

70°54'N 70°52'N

Pogik Island

EXPLANATION

Shoreline Change Rates (m/yr)

-15.2 to -5.0

-5.0 to -2.0

-2.0 to -0.3

-0.3 to +0.3

+0.3 to +2.0

+2.0 to +5.0

+5.0 to +10.9

Background image USGS DOQQ (http://earthexplorer.usgs.gov)

0 1 KILOMETER

0 1 MILE

Rate of change (meters per year)

 -15 -10 -5 0 5 10 15

Distance alongshore (kilometers)

Accretion Erosion

Pogik Bay

11 10 9 8 7 6 5 4 3 2 1 0

Distance alongshore (kilometers)

Accretion Erosion

 7 6 5 4 3 2 1 0

Rate of change (meters per year)

 -10 -5 0 5 10 

A Pogik Island

D

C

B
Historical Shoreline Change Analysis 65

Exposed Open-Ocean Shoreline Change

Open-ocean shorelines in Region 6 are predominantly 

erosional (94 percent of transects), with average shoreline 

change rates of -7.1 m/yr and a range of -18.6 to +7.3 m/yr 

(figs. 45 and 47; table 5). The highest erosion rates in the study 

area (>18 m/yr) were measured near Cameron Point, where 

over 1 km of land has eroded between 1947 and 2002. Much 

of the eroding land is low-lying and presumably composed 

mostly of ice-rich, fine-grained sediment so despite high 

erosion rates, little sediment is being added to the system to 

create a protective coastal buffer (beach). Only 6 percent of 

transects along the open-ocean coast are accretional and are 

limited to an area just north of Cape Halkett, where a spit has 

been accreting southeast into Harrison Bay, west of Cameron 

Point, near the abandoned site of Kolovik, and west of Drew 

Point, where a headland is accreting southeastward into Smith 

Bay. A remarkably stable section of coast between Lonely and 

Kolovik has only eroded on average about 65 m between 1947 

and 2002 (figs. 45 and 47).

The barrier fronting Pogik Bay migrated 300–700 m to the 

southwest and extended about 1 km to the west (average rate of 

change, -8.8 m/yr) (table 5). Nearby shoals, islands, and mudflats 

present in 1947 mostly disappeared by 2002.

140

Pogik

Bay

Pitt Point

Drew Point

Kokruagarok

McLeod 

Point

Cape Halkett

Cameron

Point Avatanak Bight

$

NAD 1983 UTM 5 

10 KILOMETERS

10 MILES

0 5

0 5

0

10

20 30 40

50

60 70

Distance alongshore (kilometers)

Rate of change (meters per year)

Accretion Erosion

 80 70 60 50 40 -20 -15 -10 -5 0 5 10 15 20 30 20 10 0

Cameron Point

Drew Point

Avatanak Bight

80

Kolovik

Kolovik

Barrier

Island

Pitt Point

McLeod 

Point

Cape Halkett

Lonely

Lonely

Figure 47. Top: Graph of shoreline change rates for exposed open-ocean coast of Region 6, Cape Halkett to Drew Point, north coast 

of Alaska. Gray bar is shoreline change rate uncertainty (±0.3 m/yr) for individual transects. Bottom: Map of coast of Region 6 indicating 

distances measured alongshore.
66 National Assessment of Shoreline Change—Historical Shoreline Changes along the North Coast of Alaska

(7) Drew Point to Dease Inlet

Introduction

Region 7 extends about 52 km between Drew Point and 

Dease Inlet and includes both exposed open-ocean mainland, 

barrier island and barrier spit shorelines and sheltered mainlandlagoon shorelines (fig. 48). It is included within the NPR-A and the 

Teshekpuk Lake Special Area. This stretch of coast is undeveloped 

and uninhabited aside from the Cape Simpson Industrial Port, an 

oilfield service camp owned and operated by Ukpeaġvik Iñupiat 

Corporation (UIC) at the former location of the Cape Simpson 

Intermediate DEW site, which was deactivated in 1963 (fig. 49A).

The exposed open-ocean coast of Region 7 includes an 

18 km section along the east side of Smith Bay between Drew 

Point and the Ikpikpuk River Delta and a 29 km stretch from 

about 1.4 km northwest of Cape Simpson to the west end of 

Kulgurak Island, as it was mapped in 1947; Kulgurak Island 

subsequently segmented into several individual islands, portions 

of which are included in Region 8 analysis. The Ikpikpuk and 

Piasuk Rivers and Deltas separate these two analysis sections 

on opposite sides of Smith Bay. The coastal plain in this area 

is characterized by low- to high-tundra with numerous, large, 

tapped and untapped thermokarst lakes (figs. 39 and 48).

The mainland-lagoon coast of Region 7 extends about 16 km 

along the shore of Fatigue Bay from approximately 1 km east of 

Sinclair River west to Tangent Point, then southwest about 12 km 

to Black Head on the eastern shore of Dease Inlet. The coast along 

this stretch is extremely low-lying, with many tapped thermokarst 

lakes and inundated tundra surfaces.

Shoreline change rates were determined from two datasets, 

1947 T-sheets and DOQQ imagery from 2002 (table 2; fig. 4). 

No historical T-sheets exist between the Piasuk River Delta 

and the section beginning 1.4 km north of Cape Simpson and 

thus no shoreline change rates were calculated for that section. 

Region 7 is dominantly erosional (92 percent of transects) with 

an average combined shoreline change rate for both exposed 

and sheltered shorelines of -2.4 m/yr and range of -16.4 to 

+3.4 m/yr (table 5). The highest accretion rates are associated 

with spit formation and infilling of inlets along the barrier 

island coast. Erosion rates are highest along the east coast of 

Dease Inlet, between Tangent Point and Black Head, likely 

a result of inundation and/or subsidence of this extremely 

155°30'W 155°W 154°30'W 154°W

71°10'N 71°N 70°50'N

EXPLANATION

0 5 10 KILOMETERS

0 5 10 MILES

Background image USGS DOQQ (http://earthexplorer.usgs.gov)

Exposed Barrier Island

Exposed Barrier Spit

Exposed Island

Exposed Mainland

Sheltered Mainland

Smith Bay

Drew Point

Boat Creek

Black

Head

Fatigue Bay

Piasuk River

Delta

Cape Simpson

Tangent Point

Sinclair

River

Mayoriak

River

Point

Poleakoon

Tulimanik Island

Ikpikpuk River Delta

Dease Inlet

Beaufort Sea

McKay Inlet

Kulgurak Island

Cape Simpson

DEW site/Industrial Port

Figure 48. Map showing color-coded shoreline change rates in Region 7, Drew Point to Dease Inlet, north coast of Alaska.
Historical Shoreline Change Analysis 67

Figure 49. Aerial photographs showing typical examples of coast of Region 7, Drew Point to Dease Inlet, north coast of Alaska. 

A, The Cape Simpson Industrial Port, an oil field service camp, at location of former Cape Simpson Distant Early Warning (DEW) 

station. B, Inundated tundra near Tangent Point, view to southeast. C, Shoreline along east coast of Smith Bay with low bluffs fronted 

by fine-grained beach. D, Coastal bluffs with no fronting beach on east coast of Smith Bay. E, Low-lying tundra with relatively wide 

fronting beach between Cape Simpson and Kulgurak Island. Note wood debris and brown color of the tundra, which indicates saltkilled vegetation owing to inundation. F, high bluffs (about 10 m) with no fronting beach between Cape Simpson and Kulgurak Island. 

(Photographs A, B, C, E, and F taken in 2006, and D taken in 2009; Gibbs and Richmond, 2009, 2010.)
68 National Assessment of Shoreline Change—Historical Shoreline Changes along the North Coast of Alaska

Figure 50. Map showing color-coded shoreline change rates in Region 7, Drew Point to Dease Inlet, north coast of Alaska. Width 

of line represents shoreline change envelope, or total shoreline change over analysis period, and distance between historical 

shorelines. Note change in scale from other figures.

low-lying coast (fig. 50). In contrast to other regions in the study 

area, average shoreline change rates in Region 7 are nearly 

twice as high along the sheltered mainland lagoon shorelines 

compared to exposed open-ocean shorelines (-3.2 and -1.9 m/yr, 

respectively) (table 5).

 Sheltered Mainland-Lagoon Shoreline Change

The sheltered mainland-lagoon coast of Region 7 is 

dominantly erosional (96 percent of transects) with average 

shoreline change rates of -3.2 m/yr and a range of -16.4 to 

+0.6 m/yr (fig. 51; table 5).

Sinclair River to Tangent Point

The lagoon coast of Fatigue Bay between the Sinclair 

River and Tangent Point is extremely low lying (<0.5m), 

predominantly inundated tundra with well-developed 

polygonal structure (fig. 49B). Low bluffs (<2 m high) outcrop 

only near Sinclair River. This section of coast is dominantly 

erosional (93 percent of transects); shoreline change rates 

average -1.3 m/yr and range from -10.3 to +0.6 m/yr (table 5). 

The highest erosion rates are along the eastern shore of a pond 

just west of the Sinclair River (figs. 50 and 51).

Tangent Point to Black Head

The complex coast along the east coast of Dease Inlet 

is a mixture of low-lying (<2 m high) tundra and tapped 

thermokarst lake bluffs fronted by a mud apron or narrow 

(likely intertidal) beach deposits (<20 m), shoals and spits 

fronting a large embayment (likely a former thermokarst lake), 

and low-lying mud flats and low tundra (<0. 5 m) near Tangent 

Point. This section of coast is erosional (100 percent of 

transects), with an average shoreline change rate of -5.5 m/yr 

and a range of -16.4 to -0.4 m/yr (table 5). The highest erosion 

155°30'W 155°W 154°30'W 154°W

71°10'N 71°N 70°50'N

EXPLANATION

0 5 10 KILOMETERS

0 5 10 MILES

Background image USGS DOQQ (http://earthexplorer.usgs.gov)

Shoreline Change Rates (m/yr)

-17.0 to -5.0

-5.0 to -2.0

-2.0 to -0.3

-0.3 to +0.3

+0.3 to +1.0

+1.0 to +2.0

+2.0 to +4.0

Smith Bay

Drew Point

Boat Creek

Black

Head

Fatigue Bay

Piasuk River

Delta

Cape Simpson

Tangent Point

Sinclair

River

Mayoriak

River

Point

Poleakoon

Tulimanik Island

Ikpikpuk River Delta

Dease Inlet

Beaufort Sea

McKay Inlet

Kulgurak Island

Cape Simpson

DEW site/Industrial Port
Historical Shoreline Change Analysis 69

Black Head

Fatigue Bay

Tangent Point

Sinclair River $

NAD 1983 UTM 5 

0 2.5 5 KILOMETERS

0 2.5 5 MILES

Distance alongshore (kilometers)

Rate of change (meters per year)

Accretion Erosion

 30 20 10 0 -20 -15 -10 -5 0 5 10 15 20

Tangent Point

30

20

10

0

Sinclair River

Dease Inlet

Black Head

Dease Inlet Fatigue Bay

McKay Inlet

McKay

Inlet

15

Tulimanik

Island

Kulgurak Island

Figure 51. Top: Graph of shoreline change rates for sheltered mainland-lagoon coast of Region 7, Sinclair River to Black Head, north 

coast of Alaska. Gray bar is shoreline change rate uncertainty (±0.3 m/yr) for individual transects. Bottom: Map of coast of Region 7 

indicating distances measured alongshore.

rates are associated with the inundation or erosion of the lowlying tundra just south of Tangent Point.

Exposed Open-Ocean Shoreline Change

The exposed open-ocean coast of Region 7 is 

dominantly erosional (89 percent of transects) with average 

shoreline change rates of -1.9 m/yr and a range of -6.8 to 

+3.4 m/yr (table 5). Average rates of shoreline change are 

somewhat lower on the northwest-facing, east side of Smith 

Bay compared to the northeast-facing section between Cape 

Simpson and Kulgurak Island (-1.5 compared to -2.1 m/yr, 

respectively), although there is no difference in average rates 

between mainland and barrier shorelines (each average

-1.9 m/yr) (figs. 50 and 52; table 5).

Drew Point to Ikpikpuk River Delta 

On the east side of Smith Bay, between Drew Point 

and the Ikpikpuk River Delta, tundra bluffs, typically 2–3 m 

high but reaching up to 7 m near Point Poleakoon, define the 

coastline. The bluffs are segmented by several small creeks, 

streams, and unnamed drainages. This section of coast 

trends NE-SW and faces northwest, from which occasional 

storm waves approach. This section of coast is dominantly 

erosional (93 percent of transects); shoreline change rates 

average -1.5 m/yr and range from -4.1 to +1.7 m/yr (table 5). 

Change rates are relatively lower between Drew Point and 

the large, unnamed drainage northeast of Point Poleakoon. 

Here the bluffs are fronted by relatively wide (<30 m) and 

continuous fine-grained beaches (fig. 49C). South of the 

drainage and along the relatively higher bluffs around Point 
70 National Assessment of Shoreline Change—Historical Shoreline Changes along the North Coast of Alaska

Smith Bay

Drew Point

Black Head

Dease Inlet

Fatigue Bay

Kurgorak Bay

Cape Simpson

Tangent Point

Sinclair

River

Point Poleakoon

$

NAD 1983 UTM 5 

10 KILOMETERS

10 MILES

0 5

0 5

0

10

20

30

40

50

60

70 Distance alongshore (kilometers)

Rate of change (meters per year)

Accretion Erosion

 80 70 60 50 40 30 20 10 0 -10 -5 0 5 10 

Ikpikpuk River

Delta

Piasuk River

Delta

Cape Simpson Drew Point

Piasuk River Delta Ikpikpuk River Delta

Smith Bay Fatigue Bay

Kulgurak

Island Tulimanik Island

Dease Inlet

Tulimanik

Island

Kulgurak Island

70 80

Figure 52. Top: Graph of shoreline change rates for exposed open-ocean coast of Region 7, Drew Point to Kulgurak Island, north coast 

of Alaska. Gray bar is shoreline change rate uncertainty (±0.3 m/yr) for individual transects. Bottom: Map of coast of Region 7 indicating 

distances measured alongshore.

Poleakoon, the beaches narrow (<5 m) and the bluffs appear 

in photographs to have a relatively higher ice content, and 

debris fans are common at their base (fig. 49D). Farther 

south, narrow beaches front lower bluffs and shoreline retreat 

change rates decrease toward Ikpikpuk River Delta.

Cape Simpson to Kulgurak Island

West of Smith Bay, between Cape Simpson and 

Kulgurak Island, the coast includes tundra bluffs 2–10 m 

high and very low-lying (~1 m high) tundra and unvegetated 

barrier spits, beaches and islands. Beaches occur along 

most of the coast, except fronting the highest bluffs in 

easternmost part of the region (figs. 49E and 49F). This 

section of coast is mostly erosional (89 percent of transects). 

Shoreline change rates average -2.1 m/yr and range from 

-6.8 to +3.4 m/yr (table 5). Accretion was measured at four 

locations: (1) at the eastern end of the section and associated 

with spit extension to the southeast; (2) associated with the 

formation of a barrier beach fronting a former embayment; 

(3) barrier migration and closure of McKay Inlet; and (4) the 

northwestern extension of Tulimanik Island and attachment 

with Kulgurak Island.
Historical Shoreline Change Analysis 71

(8) Dease Inlet to Barrow

Introduction

Region 8 stretches nearly 60 km from Dease Inlet to 

the Barrow Peninsula and includes exposed barrier spits and 

islands and sheltered mainland-lagoon shorelines (fig. 53). 

The region straddles two UTM zones (4 and 5) and is included 

within the NPR-A. The portion of the coast between Dease 

Inlet and Iko Bay is part of the TLSA. There are no villages 

or coastal infrastructure along this section of coast although 

primitive access roads have been established by off-road 

vehicle use on the spit between Barrow and Point Barrow. 

Point Barrow is also known for its numerous archeological 

sites.

Region 8 is characteristically low-lying, with coastal 

elevations generally less than 3 m, but locally as high as 

5 m, above sea level. The coastal reach is dominated by 

an extended chain of barrier islands, known as the Plover 

Islands, which are separated from the mainland coast by 

Elson Lagoon and Dease Inlet. The mainland coast includes 

tundra bluffs (3–5 m high), segmented by multiple sloughs, 

rivers, drainages, bays, and tapped (drained) thermokarst 

lakes (figs. 39 and 54). The tapped thermokarst lakes are 

more common along the shoreline east of the Mayoeak River. 

Beaches are rare along this coast and generally restricted to 

bay and rivermouth bars, pocket beaches between eroded 

bluff segments, and fronting tapped thermokarst lakes. Small, 

narrow beaches are also present adjacent to Barrow spit, near 

Tekegakrok Point, east of Mayoeak River, in Iko Bay, at Ross 

Point, at Tulageak Point, and fronting Kachiksuk Bluffs.

156°30'W 156°W 155°30'W 155°W

71°20'N 71°10'N

UTM zone 4 UTM zone 5

EXPLANATION

0 5 10 KILOMETERS

0 5 10MILES

Background image USGS DOQQ (http://earthexplorer.usgs.gov)

Exposed Barrier Island

Exposed Barrier Spit

Exposed Island

Exposed Mainland

Sheltered Mainland

Avak Bay

Avak Creek

Scott Point

Brant Point

Plover Point

Elson Lagoon

Tangent Point

Mayoeak River

Igalik Island

Doctor Island

Deadmans Island

Tekegakrok

Point

Tapkaluk

Islands

Dease Inlet

Beaufort Sea

Chukchi Sea

Barrow

Peninsula

Black

Head

Barrow spit

Iko

Bay Ross

Bay

Ross Point

Point

Barrow

Martin Island

Eluitkak Pass

Cooper Island

Tulageak

Point

Plover Islands

Christie Point

Sanigaruak Pass

Kulgurak Island

Crescent Island

Kachiksuk Bluffs Sanigaruak Island

North Salt

Lagoon

Ekilukruak Entrance

Plover Islands

Figure 53. Map showing color-coded shoreline types within Region 8, Dease Inlet to Barrow, north coast of Alaska.
72 National Assessment of Shoreline Change—Historical Shoreline Changes along the North Coast of Alaska

Figure 54. Aerial photographs showing typical examples of mainland coast of Region 8, Dease Inlet to Barrow, northern Alaska. A,

Tundra bluff fronted by scattered, pocket beaches along the mainland-lagoon coast of Elson Lagoon, view to northwest. B, Tapped 

thermokarst lake shoreline near Scott Point, view to south. C, Cuspate headland east of the Mayoeak River, view to southwest. D, 

Baymouth bar and eroding bluffs near Ikpik Slough, view to southeast. (Photographs A, C, and D taken in 2006, and B taken in 2009; 

Gibbs and Richmond, 2009, 2010).

The barrier coast of Region 8 includes the Plover Islands, 

a chain of barrier islands which extend northwest about 48 km 

between Igalik Island and Eluitkak Pass, and a barrier spit that 

extends about 5 km northwest between Plover Point and Point 

Barrow, then about 6 km southwest from Point Barrow to near 

North Salt Lagoon where the Barrow Peninsula and tundra coastal 

plain begin. The barriers are generally low lying (<2 m high) and 

narrow (<300 m wide), except near Point Barrow where shore 

parallel ridges reach up to 5 m high and the spit is nearly 900 km 

wide. The barriers are mostly unvegetated although discontinuous, 

low-lying vegetation is present in topographic lows along Barrow 

spit, at Point Barrow, and on portions of the barrier islands where 

little shoreline change has occurred since 1947 (for example, the 

west end of Cooper Island and central Tapkaluk Island (fig. 55).

Shoreline change rates for Region 8 were determined from 

two of three datasets, 1947 T-sheets and DOQQ imagery from 

2002 or 2005 (table 2; fig. 4). Region 8 is predominantly erosional 

(90 percent of transects) with combined shoreline change rates 

for both the exposed open-ocean and sheltered mainland-lagoon 

shorelines averaging -2.5 m/yr and ranging between -17.9 to +7.0 

m/yr (table 5). Average shoreline change rates along exposed 

open-ocean coasts (-3.2 m/yr) are just over 1.5 times higher 

compared to sheltered mainland-lagoon coasts (-2.1 m/yr) (fig. 56; 

table 5); however, much of the change to the barrier islands is not 

accounted for in the DSAS results due to the lack of overlapping 

shorelines.

Sheltered Mainland-Lagoon Shoreline Change

Shoreline change rates along the sheltered mainland/lagoon 

shoreline of Region 8 are predominantly erosional (95 percent 

of transects), averaging -2.1 m/yr and ranging between -9.9 and 
Historical Shoreline Change Analysis 73

Figure 55. Aerial photographs showing typical examples of barrier coast of Region 8, Dease Inlet to Barrow, northern Alaska. A. 

Cooper Island, a typical, low-lying barrier island within Region 8 located just east of Ekilukruak Entrance; view to southeast. In contrast 

to other barrier islands along coast, which are narrow, unvegetated, and experience high rates of coastal erosion, this part of Cooper 

Island has been relatively stable since 1947; it is relatively wider here and sparse vegetation can be seen in foreground of photograph. 

B, Igalik Island, a characteristic low-lying, unvegetated barrier island. Dease Inlet is on right and Kulgurak Island and Tangent Point 

are visible in the background; view to east. The island reformed in this location between 1947 and 2002. C, Linear ridges and low-lying 

vegetation at Point Barrow; view to south down Barrow spit. D. Point Barrow, showing the lobe of sediment deposited on the south side 

of the point between 1947 and 2005, view to northeast. (All photographs taken in 2006; Gibbs and Richmond, 2009).
74 National Assessment of Shoreline Change—Historical Shoreline Changes along the North Coast of Alaska

156°30'W 156°W 155°30'W 155°W

71°20'N 71°10'N

UTM zone 4 UTM zone 5

EXPLANATION

0 5 10 KILOMETERS

0 5 10MILES

Background image USGS DOQQ (http://earthexplorer.usgs.gov)

-17.9 to -5.0

-5.0 to -2.0

-2.0 to -0.3

-0.3 to +0.3

+0.3 to +2.0

+2.0 to +5.0

+5.0 to +7.0

Shoreline Change Rates (m/yr)

Avak Bay

Avak Creek

Scott Point

Brant Point

Plover Point

Elson Lagoon

Tangent Point

Mayoeak River

Igalik Island

Doctor Island

Deadmans Island

Tekegakrok

Point

Tapkaluk

Islands

Dease Inlet

Beaufort Sea

Chukchi Sea

Barrow

Peninsula

Black

Head

Barrow spit

Iko

Bay Ross

Bay

Ross Point

Point

Barrow

Martin Island

Eluitkak Pass

Cooper Island

Tulageak

Point

Plover Islands

Christie Point

Sanigaruak Pass

Kulgurak Island

Crescent Island

Kachiksuk Bluffs Sanigaruak Island

North Salt

Lagoon

Ekilukruak Entrance

Plover Islands

Figure 56. Map showing color-coded shoreline change rates in Region 8, Dease Inlet to Barrow, north coast of Alaska. Width of line 

represents shoreline change envelope, or total shoreline change over analysis period, and distance between historical shorelines.

+4.9 m/yr (figs. 56, 57; table 5). The highest erosion rates occur 

between Christie Point and Ross Point along a section of coast 

adjacent to Ekilukruak Entrance, a ~6+ km wide gap in the 

barrier island chain. Rates are relatively low between the Barrow 

Peninsula and Tekegakrok Point, except at the mouth of North 

Salt Lagoon, where the entrance channel widened and an offshore 

bar or delta disappeared between 1947 and 2005. Erosion rates 

generally increase from west to east across the region, with the 

highest erosion rates associated with Scott Point, Ross Point, and 

Christie Point, and lowest rates in Iko Bay and east of Christie 

Point. Shoreline accretion is very low along this section of coast, 

with only three areas showing >0.5 m/yr of accretion during the 

study period: north of North Salt Lagoon, west of Tekegakrok 

Point, a cuspate headland between Mayoeak River and Scott 

Point, and a spit west of Ross Point. The variation in shoreline 

change rates along the mainland lagoon coast is likely driven by 

the presence or absence of the protection from wave exposure 

offered by the off shore barrier islands.

Exposed Open-Ocean Shoreline Change

The barrier islands and spits within Region 8 show 

a dynamic and complex pattern of erosion and accretion 

between 1947 and 2002/2005. Some islands were overwashed, 

breached, and/or segmented into multiple smaller islands (for 

example, eastern Tapkaluk Islands), while others extended 

in length and/or melded into single island (for example, 

western Tapkaluk Islands). Many migrated, rotated, and 

reformed landward of their 1947 position. Because of the 

dynamic nature of these islands, the DSAS results give a 

somewhat incomplete summary of the change in the area, 

especially where new islands have formed or migrated into a 

location where no previous landform existed and there are no 

overlapping shorelines.

Shoreline change rates along the exposed open-ocean 

coast of Region 8 are predominantly erosional (82 percent of 

transects), averaging -3.2 m/yr and ranging between -17.9 and 
Historical Shoreline Change Analysis 75

Distance alongshore (kilometers)

Long-term rate of change (meters per year)

Accretion Erosion

 80 70 60 50 40 -10 -5 0 5 10  30 20 10 0

Christie Point

Ross Point

Scott Point

Ross Bay

Avak BayAvak Creek

Elson Lagoon

Tekegakrok

Point Ikpik Slough

Iko Bay

Mayoeak River

Brant Point

Dease Inlet

$

0 5 10 KILOMETERS

0 5 10 MILES

NAD 1983 UTM 4

0

10

20

40

50

60

North Salt Lake

Igalik Island

Doctor/Crescent/

Deadmans Islands

Eluitkak

Pass

Dease Inlet

Ekilukrauk

Entrance

Iko

Bay

Ross Bay

Ross

Point

Black Head

Scott Point

Brant Point

Point

Barrow

Plover Point

Elson Lagoon

Tangent Point

Martin Island

Cooper Island

Christie Point

Tekegakrok Point

Tapkaluk Islands

Sanigaruak Island

30 70

80

Figure 57. Top: Graph of shoreline change rates for sheltered mainland-lagoon coast of Region 8, Dease Inlet to Barrow, north coast 

of Alaska. Gray bar is shoreline change rate uncertainty (±0.3 m/yr) for individual transects. Bottom: Map of coast of Region 8, indicating 

distances measured alongshore.

+7.0 m/yr (figs. 56 and 58; table 5); however, because of the 

lack of overlapping shorelines, all changes to the barrier island 

shorelines are not accounted for in the DSAS analysis. Between 

1947 and 2005 the total barrier island area, and not including the 

spit between Plover Point and Barrow Peninsula, increased by 

1,022,534 m2 (table 8). Average shoreline change for the barrier 

islands between Igalik Island and Eluitkak Pass is three times 

higher than for the barrier spit between Plover Point and the 

Barrow Peninsula (-3.9 and -1.3 m/yr, respectively; table 5).There 

is an overall decrease in erosion rates from east to west, with 

the highest rates of shoreline change measured between Igalik 

and Cooper Islands. This analysis, however, does not take into 

considerable amounts of accretion and erosion observed for much 

of the Plover Islands, as described below.

Igalik Island to Sanigaruak Pass 

Marking the eastern extend of Region 8, the islands 

between Kulgurak Island and Sanigaruak Pass as mapped 

in 1947 included the ~3.5 km Igalik Island, the ~1 km long 

Sanigaruak Island, and five unnamed islands. By 2002, these 

islands had eroded and reformed as a continuous, nearly 4 km 

long island to the west of the former Igalik Island, along with 

numerous smaller islands and shoals located several hundred 

meters landward of the former island chain (fig. 59). The barrier 

islands are extremely low lying (<1.5 m high) and unvegetated. 

Average rates of shoreline change for the islands between 

Kulgurak Island and Sanigaruak Pass average -5.6 m/yr and 

range between -17.9 and +2.7 m/yr (table 5), although these rates 

do not include the considerable amounts of island accretion and 

erosion observed between 1947 and 2002. During the same time 

period, the total surface area of the Igalik and Sanigaruak Islands 

increased by 106,874 m2 (table 8).

Sanigaruak Pass to Ekilukruak Entrance

The reach between Sanigaruak Pass and the Ekilukruak 

Entrance includes Martin Island, Cooper Island, and several 
76 National Assessment of Shoreline Change—Historical Shoreline Changes along the North Coast of Alaska

Figure 58. Top: Graph of shoreline change rates for exposed open-ocean coast of Region 8, Dease Inlet to Barrow, northern Alaska. 

Gray bar is shoreline change rate uncertainty (±0.3 m/yr) for individual transects. Bottom: Map of coast of Region 8 indicating distances 

measured alongshore.

Distance alongshore (kilometers)

Rate of change (meters per year)

Accretion Erosion

 70 60 50 40 -20 -15 -10 -5 0 5 10 15 20 30 20 10 0

Point Barrow

Plover Point

Martin Island

Sanigaruak

Island

Ekilukrauk

Entrance

Sanigaruak Pass

Eluitkak Pass Tapkaluk Islands Cooper Island Igalik Island

Plover Islands

Kulgurak Island

$

0 5 10 KILOMETERS

0 5 10 MILES

NAD 1983 UTM 4

0

20 10

50 40 60

North Salt Lake

Igalik Island

Doctor/Crescent/

Deadmans Islands

Eluitkak

Pass

Dease Inlet

Ekilukrauk

Entrance

Iko

Bay

Ross Bay

Ross Point

Black Head

Scott Point

Brant Point

Point

Barrow

Plover Point

Elson Lagoon

Tangent Point

Martin Island

Cooper Island

Christie Point

Tekegakrok Point

Tapkaluk Islands

Sanigaruak Island

Table 8. Total barrier island area in Region 8, Dease Inlet to Barrow, north coast of Alaska, for each era 

and total change during analysis period, in square meters.

Island 1940s 2000s 2000s–1940s

Igalik Island 241,881 482,859 240,978

Sanigaruak Island 125,724 59,408 -66,316

Martin-Cooper Islands 1,777,350 2,153,391 376,042

Tapkaluk Island 996,898 1,768,424 771,526

Deadmans Island 188,041 334,831 146,790

Total 3,329,893 4,798,913 1,469,020
Historical Shoreline Change Analysis 77

155°40'W 155°30'W 155°20'W 155°10'W

71°14'N 71°12'N

Tangent Point

Martin Island

Igalik Island

Cooper Island

Tulageak Point

Christie Point

Sanigaruak Pass

Kachiksuk Bluffs

Sanigaruak Island

Kulgurak Island

EXPLANATION

2010

2005

1947 

0 1

Kilometers 3 0 1

Miles

156°20'W 156°10'W 156°W

71°22'N

EXPLANATION

2010

2005

1947 

0 1

Kilometers

3

0 1

Miles

Plover Point

Eluitkak Pass

Doctor/Crescent/Deadmans

Islands Tapkaluk Islands

Background image USGS DOQQ (http://earthexplorer.usgs.gov)

B

A

Figure 59. Detailed map showing shorelines of Plover Islands fronting Elson Lagoon for time periods 1947, 2005, and 2010. Note how 

barriers migrated landward and segmented into multiple islands. Lightest line is shoreline derived from 2010 lidar DEM; this shoreline, 

which was not used for DSAS analysis in this study, shows that between 2005 and 2010, Martin, Tapkaluk, and Doctor/Crescent/

Deadmans Islands reformed into a single continuous island.

unnamed smaller islands. 1947 T-sheets show a 5.7 km long 

Martin Island, 5.5 km long Cooper Island, and 3 smaller 

unnamed islands. By 2002, the central part of Martin Island 

had migrated over 600 m landward and segmented into several 

islands. The unnamed islands west of Sanigaruak Pass merged 

with the eastern part of Martin Island forming a ~3.5 km long 

island, and the inlet between Martin and Cooper Islands closed 

forming one continuous island. The central part of Cooper 

Island, one of the only vegetated landscapes within the Region 

8 barrier chain, remained relatively unchanged throughout the 

study period, although the western end of the island extended 

nearly 800 meters to the west (figs. 55 and 59). Average rates of 

shoreline change for the islands between Sanigaruak Pass and 

the Ekilukruak Entrance average -3.3 m/yr and range between 

-13.2 and +4.1 m/yr (table 5), although these rates do not include 

the considerable accretion associated with the closure of the inlet 

between Martin and Cooper Islands, nor the westward extension 

of Cooper Island. During the same time period, the total surface 

area of the Martin and Cooper Islands increased by 224,033 m2 

(table 8).

Ekilukruak Entrance to Eluitkak Pass

The reach between Ekilukruak Entrance and Eluitkak 

Pass includes the Tapkaluk Islands chain, and Deadmans, 

Crescent, and Doctor Islands. Between 1947 and 2002, the 

eastern part of the Tapkaluk Islands migrated ~500 m landward 

and extended southeast about 800 m into Ekilukruak Entrance 

while the western part of the island migrated on the order 

of 125 m landward and extended ~800 m to the northwest. 

Deadmans, Crescent, and Doctor Islands coalesced into one 

island separated by two small, ephemeral inlets. Average rates 

of shoreline change for the islands between Sanigaruak Pass 

and the Ekilukruak Entrance average -3.9 m/yr and range 

between -10.5 and +3.6 m/yr (table 5), although these rates 

do not include the considerable accretion associated with the 

northwestward and southeastward extension of the Tapkaluk 

Islands and coalescence of Deadmans, Crescent, and Doctors 

Islands. During the same time period, the total surface area of 

the Tapkaluk and the coalesced Doctors Islands increased by 

691,627 m2 (table 8).
78 National Assessment of Shoreline Change—Historical Shoreline Changes along the North Coast of Alaska

Plover Point to Barrow Peninsula

The barrier spit coast between Plover Point and the 

Barrow Peninsula shows a much less dynamic shoreline 

change history compared to the Plover Islands to the east. 

Between 1947 and 2005, the NE, Beaufort Sea-facing 

shoreline between Plover Point and Point Barrow, the 

migrated 75-200 m (average -2.2 m/yr) to the southwest, 

while maintaining a similar overall morphology. At Point 

Barrow, erosion has exposed and continues to threaten 

numerous ancient burial and archeological sites.

Along the NW, Chukchi Sea facing spit, the shoreline 

at Point Barrow shows both erosion (<200 m) and accretion 

(up to 400 m) as the tip appears to have migrated to the south. 

Southward from Point Barrow, shoreline change rates are 

initially accretional then transition to predominantly erosional 

(average, -0.6 m/yr). Erosion rates are highest about 2/3 of the 

way down the spit along the low-lying and narrow portion of 

the spit near the western extent of Region 8.

(9) Barrow to Peard Bay

Introduction

The coast of Region 9 extends from the northern extent 

of the tundra backed coast of the Barrow Peninsula near North 

Salt Lagoon nearly 90 km southwest to Tachinisok Inlet on the 

east side of Peard Bay (fig. 60). In contrast to the Beaufort Sea 

coast to the east, this coastal stretch generally faces northwest, 

trends southwest to northeast, and fronts the Chukchi Sea. 

The reach includes the village of Barrow, the largest city (with 

a 2010 census population of 4,346; State of Alaska, 2015) 

and economic center of the North Slope Borough, and marks 

the seaward boundary of the NPR-A. Much of the village of 

Barrow is fronted by a low berm or bluff (1–2 m high) seaward 

of the coastal road and in many locations coastal protection 

structures are present (fig. 61A). The reach is characterized by 

a low-lying coast (< 3 m high) northeast of the Wiley-Post-Will 

158°30'W 158°W 157°30'W 157°W 156°30'W

71°20'N 71°N

EXPLANATION

Background image courtesy UAF-GINA (http://alaskamapped.org/bdl); includes material © CNES 2011, Distribution Spot Image S.A., France, SICORP, USA, all rights reserved.

0 5 10 KILOMETERS

0 5 10 MILES

Exposed Barrier Island

Exposed Barrier Spit

Exposed Island

Exposed Mainland

Sheltered Mainland

Will Rogers and Wiley Post Memorial

Browerville

Barrow

Nulavik

Walakpa Bay

Skull Cliff

Elson Lagoon

Kikolik Creek

Singaruak Creek

Tachinisok Inlet

North Salt Lagoon

Peard

Bay

Nunavak Bay

Figure 60. Map showing color-coded shoreline types within Region 9, Barrow to Peard Bay, north coast of Alaska.
Historical Shoreline Change Analysis 79

Figure 61. Aerial photographs showing typical examples of coast of Region 9, Barrow to Peard Bay, north coast of Alaska. A, Town 

of Barrow, Alaska. Shore-protection structures are common and beaches are narrow along this low-lying coastal stretch. View to 

southeast. B, Highest bluffs in study area present within Region 9 at Skull Cliff, where they reach nearly 25 m high. Relatively resistant 

layer is present at base of bluffs, and beaches are rare along this section of coast. C, Nearly vertical bluff faces north of Skull Cliff. D, 

Faceted, sloping, and vegetated bluffs between the Walakpa River and Nunavak Bay, indicating differences in geology and erosional 

history. (Photographs A and C taken in 2006, and B and D taken in 2009; Gibbs and Richmond, 2009, 2010).

Rogers Memorial Airport where it transitions to coastal bluffs 

~5–25 m high segmented by numerous small creeks, drainages, 

and bays. No major rivers reach this section of coast although 

many smaller creeks and the large Walakpa Bay reach the coast. 

Bluff heights generally increase from north to south; the highest 

bluffs in the study area (~25 m high) are found near Skull Cliff 

(figs. 61A–D). Narrow (<40 m wide) sand and gravel beaches 

are common along this coast and are absent only fronting the 

high bluffs near Skull Cliff. Wider (<150 m) beaches and spits 

typically front the coastal creeks and bays.

Exposed Open-Ocean Shoreline Change

Shoreline change rates for Region 9 were determined 

from three data sets, 1947 T-sheets, DOQQ imagery from 

2005 and the 2010 lidar DEM (table 2; fig. 4). The region 

only includes exposed open-ocean shorelines (fig. 60). 

Shoreline change rates along this coast are the lowest in 

the study area, with maximum erosion and accretion rates 

of -1.2 m/yr and +0.7 m/yr, and respectively. The reach is 

predominantly erosional (86 percent of transects) with an 

average shoreline change rate of is -0.3 m/yr, which is at the 

limit of the analytical uncertainty on individual transects 

(fig. 62; table 5). Highest accretion rates (+0.7 m/yr) were 

measured between Walakpa River and Nunavak Bay. Highest 

erosion rates (-1.2 m/yr) were measured between Oyagatut 

Creek and Killi Creek. There is a relative increase in erosion 

rates about 2.5 km north of Nulavik where average rates 

nearly double from -0.2 m/yr to the north to -0.4 m/yr to the 

south (figs. 62 and 63; table 5).
80 National Assessment of Shoreline Change—Historical Shoreline Changes along the North Coast of Alaska

158°30'W 158°W 157°30'W 157°W 156°30'W

71°20'N 71°N

EXPLANATION

Background image courtesy UAF-GINA (http://alaskamapped.org/bdl); includes material © CNES 2011, Distribution Spot Image S.A., France, SICORP, USA, all rights reserved.

0 5 10 KILOMETERS

0 5 10 MILES

-1.2 to -1.0

-1.0 to -0.5

-0.5 to -0.3

-0.3 to +0.3

+0.3 to +0.5

+0.5 to +0.7

Shoreline Change Rates (m/yr)

Will Rogers and Wiley Post Memorial

Browerville

Barrow

Nulavik

Walakpa Bay

Skull Cliff

Elson Lagoon

Kikolik Creek

Singaruak Creek

Tachinisok Inlet

North Salt Lagoon

Peard

Bay

Nunavak Bay

Figure 62. Map showing color-coded shoreline change rates in Region 9, Barrow to Peard Bay, north coast of Alaska. Width of line 

represents shoreline change envelope, or total shoreline change over analysis period, and distance between historical shorelines. 

Note change in in rate legend compared to other shoreline change maps and relatively higher erosional rates south of Nulavik 

compared to north of Nulavik.
Historical Shoreline Change Analysis 81

Distance alongshore (kilometers)

Rate of change (meters per year)

Accretion Erosion

 -5 -2.5 0 2.5 5 90 80 70 60 50 40 30 20 10 0

Barrow

Kikolik Creek Walakpa Bay

Nulavik

0 10

20

30

40

50

70 60

80

90

Barrow

Nulavik

Walakpa Bay

Skull Cliff

Nunavak Bay

Killi Creek

Browerville

Brant Point

Walakpa River

Papigak Creek

Kunarak Creek Kikolik Creek

Nalimiut Point

Singaruak Creek

Tachinisok Inlet $

0 5 10 KILOMETERS

0 5 10 MILES

NAD 1983 UTM 4

Figure 63. Top: Graph of shoreline change rates for exposed open-ocean coast of Region 9, Barrow to Peard Bay, north coast of 

Alaska. Gray bar is total shoreline change rate uncertainty (±0.3 m/yr) for individual transects. Bottom: Map of coast of Region 9 

indicating distances measured alongshore.
82 National Assessment of Shoreline Change—Historical Shoreline Changes along the North Coast of Alaska

(10) Peard Bay to Icy Cape 

Introduction

The coast of Region 10 extends approximately 180 km 

southwest along the coast of the Chukchi Sea from the east end 

of Peard Bay to the western boundary of the study area at Icy 

Cape Pass (fig. 64). The Native Village of Wainwright, with 

556 residents (2010 census; State of Alaska, 2015), is the only 

population center and infrastructure development along this stretch 

of coast.

Region 10 includes exposed open-ocean and sheltered lagoon 

coasts. The coastal plain includes low to relatively high tundra 

with numerous, large, thermokarst lakes generally elongated in 

an NW-SE orientation. Two large estuaries, Wainwright Inlet and 

Kugrua Bay and, five large rivers (Kugrua River which drains 

into Kugrua and Peard Bays, and the Sinaruruk, Kuk, which feeds 

Wainwright Inlet, Nokotlek and Avak Rivers) segment the coast. 

Barrier spits and islands front the coast of Peard Bay and between 

Kilmantavi and Icy Cape Pass. Narrow barrier beaches connected 

to the mainland at both ends and enclosing lagoons, are present 

near Point Belcher and between the Kuk River and Kilmantavi.

Shoreline change rates for Region 10 were determined from 

several datasets, 1947 and 1949 T-sheets; 2010, 2011, and 2012 

lidar DEMs; and 2010 and 2011 SPOT5 satellite orthoimagery 

(table 2; fig. 4). Shoreline change rates for parts of the lagoon 

coast near Icy Cape were not included in the analysis because 

the shoreline could not accurately be delineated from the 2000s 

era data sources (fig. 65). Comparison of 2010 SPOT5 satellite 

imagery (http://www.alaskamapped.org; accessed November 22, 

2014) with shorelines derived from the 2011 lidar DEM shows 

this area is a very low-lying with a poorly defined shoreline which 

presents difficulties in deriving a lidar shoreline (fig. 65). Region 

10 is predominantly erosional (71 percent of transects) with 

combined shoreline change rates for both the exposed open-ocean 

and sheltered mainland-lagoon coasts averaging -0.3 m/yr, which 

is equal to the total shoreline change rate uncertainty at individual 

transects. Average rates of change for the sheltered mainlandlagoon coast compared to the exposed open-ocean coast are not 

Atanik

Icy Cape

Peard Bay

Kuk River

Wainwright

Kugrua Bay

Kilmantavi

Avak River

Avak Point

Walik Creek

Pingasagruk

Nivat Point

Kugrua River

Point Belcher

Point Franklin

Nokotlek Point

Sinaruruk River

Pingorarok Pass

Pingorarok Hill

Wainwright Inlet

Tachinisok Inlet

Akoliakatat Pass

Eluksingiak Point

Mitliktavik

Icy Cape Pass

Asiniak Point

Nokotlek River

Nalimiut Point

Seahorse Islands

162°W 161°30'W 161°W 160°30'W 160°W 159°30'W 159°W 158°30'W

71°N 70°40'N 70°20'N

EXPLANATION

Background image courtesy UAF-GINA (http://alaskamapped.org/bdl); includes material © CNES 2011, Distribution Spot Image S.A., France, SICORP, USA, all rights reserved.

0 5 10 KILOMETERS

0 5 10 MILES

Exposed Barrier Island

Exposed Barrier Spit

Exposed Mainland

Sheltered Mainland

Exposed Barrier Beach

Figure 64. Map showing color-coded shoreline types within Region 10, Peard Bay to Icy Cape, north coast of Alaska.
Historical Shoreline Change Analysis 83

161°54'W 161°52'W 161°50'W 70°18'N 70°16'N

1947

2011

EXPLANATION

Historical Shorelines

161°54'W 161°52'W 161°50'W

Elevation

(meters-E)

High : 32

Low : -3

0 0.5 1 Miles

0 0.5 1 Kilometers

A B

significantly different, (-0.3 and -0.4 m/yr, respectively), however, 

the overall range in rates along the mainland-lagoon coast (-2.2 

to +2.0 m/yr) is considerably lower compared to the open-ocean 

coast (-8.5 to +8.0 m/yr) (table 5). These higher rates along the 

open-ocean coast reflect erosion and accretion at the ends of 

barrier spits and islands associated with island breaching, infilling 

and inlet migration (figs. 66–68).

Sheltered Mainland-Lagoon Shoreline Change

The sheltered mainland-lagoon coast of Region 10 includes 

a ~40 km stretch within Peard Bay and a ~60 km stretch between 

Kilmantavi and Icy Cape Pass (fig. 64). The exposed mainland 

lagoon coast of Region 10 is predominantly erosional (77 percent 

of transects) with shoreline change rates averaging -0.3 m/yr, and 

ranging between -2.2 and +2.0 m/yr (table 5). The highest and 

lowest erosion rates along this stretch of coast are associated to the 

erosion and migration of barrier islands and their adjacent inlets 

(figs. 66 and 67; table 5).

Peard Bay

Within Peard Bay, the mainland coast is characterized by 

tundra bluffs varying between 3 and 8 m high except within 

Tachinisok Inlet and fronting the numerous small drainages and 

tapped thermokarst lakes near Kugrua Bay where no bluffs are 

present. Beaches are generally less than 25 m wide except along 

cuspate headlands, at Nalimuit Point, Walik Creek, Eluksingiak 

Point, and Asiniak Point where wider beaches occur (fig. 69A). 

The average rate of shoreline change for this coast is the same 

as the regional average of -0.3 m/yr but with a range between 

-2.2 and +1.7 m/yr (table 5). Relatively higher rates of change, 

both accretion and erosion, were measured near the headlands 

mentioned above.

Kilmantavi to Icy Cape 

The lagoon coast between Kilmantavi and Icy Cape is 

similar to the Peard Bay coast, although bluffs reach up to 12 m 

high near Pingorarok Hill. The coast between the Nokotlek 

Figure 65. Map showing historical shorelines plotted over A, 2010 satellite image, and B, 2011 Digital Elevation Model of Icy of the 

lagoon coast near Icy Cape. Low elevation and discontinuous remnant tundra islands precluded reasonable shoreline change rates 

from being determined for this area.
84 National Assessment of Shoreline Change—Historical Shoreline Changes along the North Coast of Alaska

Atanik

Icy Cape

Peard Bay

Kuk River

Wainwright

Kugrua Bay

Kilmantavi

Avak River

Avak Point

Walik Creek

Pingasagruk

Nivat Point

Kugrua River

Point Belcher

Point Franklin

Nokotlek Point

Sinaruruk River

Pingorarok Pass

Pingorarok Hill

Wainwright Inlet

Tachinisok Inlet

Akoliakatat Pass

Eluksingiak Point

Mitliktavik

Icy Cape Pass

Asiniak Point

Nokotlek River

Nalimiut Point

Seahorse Islands

162°W 161°30'W 161°W 160°30'W 160°W 159°30'W 159°W 158°30'W

71°N 70°40'N 70°20'N

EXPLANATION

Background image courtesy UAF-GINA (http://alaskamapped.org/bdl); includes material © CNES 2011, Distribution Spot Image S.A., France, SICORP, USA, all rights reserved.

0 5 10 KILOMETERS

0 5 10 MILES

Shoreline Change Rates (m/yr)

-8.5 to -5.0

-5.0 to -2.0

-2.0 to -0.3

-0.3 to +0.3

+0.3 to +2.0

+2.0 to +5.0

+5.0 to +8.0

Figure 66. Map showing color-coded shoreline change rates in Region 10, Peard Bay to Icy Cape, north coast of Alaska. Width of line 

represents shoreline change envelope, or total shoreline change over analysis period, and distance between historical shorelines.
Historical Shoreline Change Analysis 85

Icy Cape

Peard Bay

Wainwright

Kugrua Bay

Avak River

Nivat Point Walik Creek

Point Belcher

Asiniak Point Point Franklin

Nokotlek River

Nokotlek Point Pingorarok Hill

0

10

20

30

40

100

120

130 150

160

Distance alongshore (kilometers)

Rate of change (meters per year)

Accretion Erosion

 175 150 125 100 75 50 25 0

Peard Bay

Mitliktavik 

140

170

Nokotlek River

Avak River

Nokotlek Point

Kugrua Bay

Nalimiut

Point

Eluksingiak

Point

Eluksingiak Point

Asiniak Point

Wainwright Inlet/

Kuk River

Walik Creek

110

Avak Point

180

0 -4 -2 4 2

$

0 5 10 KILOMETERS

0 5 10 MILES

NAD 1983 UTM 4

Tachinisok

Inlet

Kilmantavi

Kilmantavi

Pingorarok

Pass

Akoliakatat

Pass

Kasegaluk Lagoon

Kasegaluk Lagoon

Figure 67. Top: Graph of shoreline change rates for sheltered mainland-lagoon coast of Region 10, Peard Bay to Icy Cape, north 

coast of Alaska. Gray bar is shoreline change rate uncertainty (±0.3 m/yr) for individual transects. Bottom: Map of coast of Region 10 

indicating distances measured alongshore.
86 National Assessment of Shoreline Change—Historical Shoreline Changes along the North Coast of Alaska

Akvat Ikpilgok

Icy Cape

Wainwright Inlet/ Peard Bay

Kuk River

Wainwright

Kugrua Bay Avak River

Tachinisok

Inlet

Point

Marsh Igklo River

Point Belcher

Avgumun Creek

Asiniak Point

Point Franklin

Nokotlek

Point

Atanik 

Pingasagruk 

Mitliktavik 0

10

20

30

40 50 60

80

90

70

Distance alongshore (kilometers)

Rate of change (meters per year)

Accretion Erosion

 160 140 120 100 80 60 40 20 0 -10 -5 0 5 10

100

110 130 120 140

170

Peard Bay

Atanik 

Wainwright Point Belcher

Icy Cape

150

160

Wainwright Inlet/

Kuk River

Seahorse

Islands

Point Franklin

Pingasagruk 

Point

Marsh

Kilmantavi

Kilmantavi

Pingorarok Pass

Pingorarok

Pass

Kasegaluk Lagoon

Kasegaluk Lagoon

Akoliakatat

Pass

Akoliakatat Pass

$

0 5 10 KILOMETERS

0 5 10 MILES

NAD 1983 UTM 4 Icy Cape Pass

Figure 68. Top: Graph of shoreline change rates for exposed open-ocean coast of Region 10, Peard Bay to Icy Cape, north coast of 

Alaska. Note high rates of erosion and accretion at inlets, and increase in erosion rates west of about kilometer 145. Gray bar is the 

shoreline change rate uncertainty (±0.3 m/yr) for individual transects. Bottom: Map of coast of Region 10 indicating distances measured 

alongshore.
Historical Shoreline Change Analysis 87

Figure 69. Aerial photographs showing typical examples of sheltered mainland-lagoon coast of Region 10, Peard Bay to Icy Cape, 

north coast of Alaska. A, Nalimiut Point, a cuspate headland on the mainland-lagoon coast of Peard Bay. Moderately-high tundra bluffs 

are visible in the background, view to southeast. B, Low to moderately high tundra bluffs near Nokotlek Point, view to the southeast. C, 

The low-lying coast near Avak Point with narrow beaches and numerous, large, thermokarst lakes on coastal plain, view to south. D, 

Low-lying coast near Icy Cape with inundated tundra and exposed mudflats. (All photographs taken in 2009; Gibbs and Richmond, 2010).

River and Icy Cape is lower-lying and the adjacent coastal plain 

comprises numerous and considerably larger thermokarst lakes. 

Beaches along this section are relatively narrow although several 

cuspate headlands are present such as Nokotlek Point and Nivat 

Points (fig. 69B). Shoreline change rates along this section of 

coast average -0.3 m/yr and range between -2.1 and +2.0 m/yr. 

Approximately 6 km west of Nivat Point, near Akoliakatat Pass, 

and continuing west toward Icy Cape the shoreline change trend 

becomes almost entirely erosional (94 percent of transects) and the 

average rate of shoreline change for this segment nearly doubles 

to -0.6 m/yr (figs. 66 and 67; table 5). In contrast to the coast to 

the east where >2 m high coastal bluffs are common, this section 

of coast is characterized by low-lying bluffs (<2 m) and numerous 

tapped thermokarst lakes (figs. 69C and 69D).

Exposed Open-Ocean Shoreline Change

The exposed open-ocean coast of Region 10 comprises 

barrier islands, barrier spits, barrier beaches, and tundra-bluff 

backed mainland beaches (fig. 64). Barrier islands include the 

Seahorse Islands, which mark the east side of Peard Bay, and a 

chain of islands starting between Kilmantavi and Mitliktavik and 

continuing west to the cuspate headland at Icy Cape and Icy Cape 

Pass. Barrier spits extend west from Tachinisok Inlet into Peard 

Bay, between Point Franklin and the abandoned site of Atanik, 

fronting Wainwright Inlet, and west from the abandoned site of 

Kilmantavi toward Mitliktavik. Barrier beaches front lagoons 

near Point Belcher and between Wainwright Inlet and Kilmantavi. 

Between Atanik and Kilmantavi the coast is predominantly 

mainland, high-tundra backed beaches.

The barrier islands, spits, and beaches in this region 

are low-lying (< ~2.5 m high), generally < 150 m wide, and 

mostly unvegetated to sparsely vegetated (figs. 70A–C). Wider, 

higher, and more well-vegetated areas are found near Icy Cape, 

Akoliakatat Pass, the spit south of Wainwright Inlet, Point Belcher 

and Pingasagruk, a pre-historical whaling village and Inupiat 

winter-house site (Reinhardt, 1993). The presence of welldeveloped vegetation on the barriers suggests historical stability 

and limited overwash of these locations relative to unvegetated 

portions of the barrier islands. Along the exposed, open-ocean 
88 National Assessment of Shoreline Change—Historical Shoreline Changes along the North Coast of Alaska

Figure 70. Aerial photographs showing typical examples of exposed open-coast shore types of Region 10, Peard Bay to Icy Cape, 

north coast of Alaska. A, Sparsely vegetated barrier spit near Point Franklin with coal deposits in the nearshore. B, Unvegetated barrier 

spit fronting a narrow lagoon between Kilmantavi and Mitliktavik. C, Densely vegetated, remnant tundra barrier island near Pingasagruk. 

D, Village of Wainwright fronted by shore protection structures. All views are to south. (All photographs taken in 2009; Gibbs and 

Richmond, 2010).

mainland coast between Atanik and Kilmantavi, beaches front 

bluffs, which reach up to 10 m high, and lagoons such as those 

near Point Belcher and southwest of Wainwright Inlet. The 

beaches are generally less than 100 m wide along this coast, but 

are relatively narrow fronting the village of Wainwright (<20 m), 

where shore protection structures are common (fig. 70D).

The exposed open-ocean coast of Region 10 is erosional 

(66 percent of transects, with shoreline change rates averaging 

-0.4 m/yr and ranging from -8.5 to +8.0 m/yr) (table 5). The 

barrier island and spits along the coast of Region 10 show little 

change over the study period (averaging -0.5 m/yr) except 

adjacent to inlets and are only slightly higher compared to the 

exposed mainland shorelines (0.0 m/yr) or the regional average 

(-0.3 m/yr). The coastal reach between Kilmantavi and Icy Cape 

Pass has a higher average rate of erosion (-0.8 m/yr) compared to 

other coastal segments in the region (figs. 66, 68; table 5). Many 

of the barrier islands and spits have migrated landward from their 

1940s location, but maintained a similar overall morphology and 

orientation. The spit between Point Franklin and Atanik shows a 

regular, alongshore pattern of alternating erosion and accretion, 

with up to 170 and 180 m of shoreline erosion and accretion, 

respectively, but an overall average rate of change of 0.0 m/

yr (table 5; fig. 71A). Patterns of inlet migration at Wainwright 

Inlet, Pingorarok Pass, and Icy Cape Pass, suggests a dominant 

easterly littoral transport direction along this section of coast 

(fig. 71). The spit at the southern shore of Wainwright Inlet 

accreted over 200 m and migrated nearly 400 m to the northeast, 

resulting in over 250 m of erosion the northeast bank of the inlet. 

The spit at Pingorarok Pass migrated over 1,300 km to the east 

and the inlet narrowed from 950 m in 1949 to less than 200 m in 

2011. The spit at Akoliakatat Pass migrated to the southwest and 

narrowed the inlet from 1,300 m in 1949 to about 600 m in 2011. 

Two inlets formed between 1949 and 2011, near Nokotlek Point 

and north of Mitliktavik. The spit west of Icy Cape Pass migrated 

nearly 1,500 m to the northeast narrowing the channel from 700 

to 180 m.
Historical Shoreline Change Analysis 89

Icy Cape

Icy Cape Pass

162°W 161°58'W 161°56'W 161°54'W 161°52'W 161°50'W

70°18'N 162° W

3

0 1 Miles

0 1 Kilometers

Nivat Point Nokotlek River

Nokotlek Point

Pingorarok Pass

Akoliakatat Pass

161°20'W 161°10'W 161°W 160°50'W

70°18'N 70°16'N

3

0 1 Miles

0 1 Kilometers

2

2

Kuk River Wainwright

160°10'W 160°5'W

70°35'N 160°10'W

70°37'N 70°39'N

3

0 1Miles

0 1Kilometers

Atanik

Pingasagruk

Asiniak Point

Point Franklin

159°20'W 159°10'W 159°W 158°50'W

70°52'0"N 70°50'0"N

3 0 1 2 Miles

0 1 2 Kilometers

EXPLANATION Shoreline Change Rates 

-8.5 to -5.0

-5.0 to -3.0

-3.0 to -0.3

-0.3 to +0.3

+0.3 to +3.0

+3.0 to +5.0

+5.0 to +8.0

Historical Shorelines

1940s

2010s

Background image courtesy UAF-GINA (http://alaskamapped.org/bdl); includes material © CNES 2011, Distribution Spot Image S.A., France, SICORP, USA, all rights reserved.

A

D

C

B

Figure 71. Detailed maps showing four examples of shoreline change patterns on barrier islands and spits within 

Region 10, Peard Bay to Icy Cape, north coast of Alaska, between 1947/49 and 2010/11. A, Regular, alternating patterns 

of shoreline erosion and accretion near Pingasagruk. B, Nearly 400 m of northeastward migration of Wainwright Inlet. 

C, Akoliakatat Pass migrated to the southwest and narrowed by nearly 700 m, an inlet formed in the barrier island near 

Nokotlek Point breached between 1949 and 2011, and Pingorarok Pass migrated more than 1,300 km to the east and the 

inlet narrowed by over 700 m. D, Spit west of Icy Cape Pass migrated nearly 1,500 m to northeast, narrowing the channel 

by over 500 m.
90 National Assessment of Shoreline Change—Historical Shoreline Changes along the North Coast of Alaska

Figure 72. Map showing color-coded shoreline change rates for the north coast of Alaska, U.S.-Canadian border to Icy Cape and 

the boundaries of the ten analysis areas discussed in this report (dashed boxes and numbers).

6 7

8

2 1

4

5

9

10

3

160°W 155°W 150°W 145°W 140°W

72°N

71°N

70°N

0 50KILOMETERS

0 50MILES

Shoreline Change Rates (m/yr)

-18.6 to -5.0

 -5.0 to -2.0

 -2.0 to -0.3

 -0.3 to + 0.3 +0.3 to + 2.0 +2.0 to + 5.0

 +5.0 to +10.9

EXPLANATION

Smith Bay

Point Barrow

Prudhoe Bay

Barter Island

Kaktovik

Demarcation

Bay

Harrison

Bay

Elson Lagoon

Peard Bay

Icy Cape

Drew Point

Camden Bay

Cape Halkett

Pogik

Bay Wainwright

BEAUFORT SEA

CHUKCHI SEA

ARCTIC NATIONAL WILDLIFE REFUGE

NATIONAL PETROLEUM RESERVE ALASKA

U.S.-Canadian border

Discussion and Additional 

Considerations 

The total length of coastline evaluated along the north 

coast of Alaska between the U.S.- Canadian border and Icy 

Cape is approximately 1650 km. Due to data gaps, typically 

around river deltas, or where historical data are lacking, the 

shoreline change analysis presented in this report covers 

approximately 80 percent of the coast. Shoreline change was 

found to be highly variable alongshore, with widely ranging 

rates of erosion and accretion common over short distances.

In order to maintain consistency with other NASC 

reports, the term erosion as used in this study indicates the 

measured landward movement or retreat of the shoreline. 

No distinction was made between physical erosion and land 

loss or shoreline retreat as a result of breaching of coastal 

lake shorelines or flooding of the coast due to sea-level rise 

and/or land subsidence; in this context erosion and retreat 

are interchangeable. Accretion as used in this study indicates 

the measured seaward progradation of the shoreline and, 

particularly in case of barrier islands and spits, may also 

represent the migration alongshore of a landscape feature. 

Where shoreline change rates were quantified, the 

average rate of shoreline change for the entire study area 

was -1.4 m/yr with a range between -18.6 and +10.9 m/yr 

(fig. 72). This rate is based on 26,567 individual transects of 

which 84 percent were determined to be eroding (table 9). 

The calculated uncertainty on all shoreline change rates is 

±0.3 m/yr. Average shoreline change rates along the Beaufort 

Sea coast, which represents 72 percent of the study area, is 

more than 5 times higher than along the Chukchi Sea coast 

(-1.7 and -0.3 m/yr, respectively).

The highest rates of both erosion and accretion in the study 

area were measured within Region 6, with rates of erosion greater 

than 18 m/yr between Cape Halkett and Pogik Bay and rates of 

accretion greater than 10.5 m/yr on the west side of Pogik Bay. 

The highest average rates of shoreline change (-6.3 m/yr) were 

measured within Region 6 and the lowest (-0.3 m/yr) along the 

Chukchi coast in Regions 9 and 10 (fig. 72).

Shoreline type and exposure is an important factor in 

observed shoreline change rates (table 9). Sheltered shorelines 

comprise 42 percent of all transects and 88 percent are erosional. 

Open-ocean exposed shorelines comprise 58 percent of all 

transects and 81 percent are erosional. Average shoreline change 

rates along exposed shorelines are twice as high (-1.8 m/yr) 

compared to sheltered shorelines (-0.9 m/yr). Barrier shoreline 

transects (including barrier islands, spits, and beaches) comprise 

29 percent of the total transects and 50 percent of all exposed 

shoreline transects. Average shoreline change rates on barrier 

shorelines are not significantly different than exposed mainland 

shorelines (-1.7 and -1.8 m/yr); however, mainland shorelines 

(sheltered and exposed) have the lowest percent of erosional 

transects (12 percent) of all shoreline types. As discussed in 

the regional descriptions above, considerable migration and 

translation in the position of the barrier islands and spits resulting 

in substantial erosion and accretion was observed over the study 

period. Because of the lack of corresponding shoreline positions, 

some of these changes could not be measured using the DSAS 

method of analysis, particularly in Regions 3, 4, and 8. In those 

regions, there was a nearly 10 percent net increase (1,737,529 m2) 

in total barrier island surface area during the study period.
Discussion and Additional Considerations 91

Table 9. Summary of shoreline change rates for study area and each region relative to shoreline type. 

Shoreline type Number of 

transects

Average of 

rates (m/yr)

Maximum rate (m/yr) Percent of transects Percent of 

study area Erosion Accretion Eroding Accreting

Study Area: U.S.-Canadian border to Icy Cape 

All transects 26,567 -1.4 -18.6 10.9 84 16 100

Beaufort Sea coast 19,222 -1.7 -18.6 10.9 88 12 72

Chukchi Sea coast 7,345 -0.3 -8.5 8.0 74 25 28

All sheltered shorelines 11,199 -0.9 -16.4 10.9 88 11 42

All exposed shorelines 15,368 -1.8 -18.6 9.6 81 19 58

All mainland shorelines 18677 -1.2 -18.6 10.9 12 88 70

Only exposed mainland 7,478 -1.8 -18.6 7.3 87 12 28

Only exposed barriers (island, spit, beach) 7,725 -1.7 -17.9 9.6 75 25 29

Only exposed islands 165 -1.0 -2.6 0.9 92 8 0

Region 1: U.S.-Canadian border to Jago River

All Transects 3,673 -1.0 -13.5 5.5 86 14 14

Sheltered shorelines 1,705 -0.5 -3.0 1.7 90 9 6

Exposed shorelines 1,968 -1.4 -13.5 5.5 82 18 7

Region 2: Jago River to Staines River

All Transects 3,464 -1.1 -16.5 9.6 84 15 13

Sheltered shorelines 1,749 -0.5 -4.5 1.9 85 14 7

Exposed shorelines 1,715 -1.6 -16.5 9.6 83 17 6

Region 3: Staines River to Sagavanirktok River 

All transects 2,162 -1.5 -16.8 6.7 89 11 8

Sheltered shorelines 1,439 -0.8 -4.4 2.7 93 6 5

Exposed shorelines 723 -3.0 -16.8 6.7 81 19 3

Region 4: Sagavanirktok River to Colville River 

All transects 2,973 -1.1 -14.7 7.0 85 15 11

Sheltered shorelines 1,918 -0.8 -4.2 1.2 95 5 7

Exposed shorelines 1,055 -1.6 -14.7 7.0 66 34 4

Region 5: Colville River to Cape Halkett

All transects (all exposed) 1,989 -1.1 -9.6 5.0 92 8 7

Region 6: Cape Halkett to Drew Point

All transects 1,545 -6.3 -18.6 10.9 90 10 6

Sheltered shorelines 202 -0.5 -5.7 10.9 62 38 1

Exposed shorelines 1,343 -7.1 -18.6 7.3 94 6 5

Region 7: Drew Point to Dease Inlet

All transects 1,315 -2.4 -16.4 3.4 92 8 5

Sheltered shorelines 457 -3.2 -16.4 0.6 96 4 2

Exposed shorelines 858 -1.9 -6.8 3.4 90 10 3

Region 8: Dease Inlet to Barrow

All transects 2,228 -2.5 -17.9 7.0 90 10 8

Sheltered shorelines 1,406 -2.1 -9.9 4.9 95 5 5

Exposed shorelines 822 -3.2 -17.9 7.0 82 18 3

Region 9: Barrow to Peard Bay

All transects (all exposed) 1,779 -0.3 -1.2 0.7 86 14 7

Region 10: Peard Bay to Icy Cape 

All transects 5,439 -0.3 -8.5 8.0 71 29 20

Sheltered shorelines 2,323 -0.3 -2.2 2.0 77 23 9

Exposed shorelines 3,116 -0.4 -8.5 8.0 66 33 12

[m/yr, meters per year]
92 National Assessment of Shoreline Change—Historical Shoreline Changes along the North Coast of Alaska

Influence of Human Activities

The influence of local human activities on the Arctic 

coast is relatively modest compared to the remainder of the 

U.S. coastline. Coastal development is limited to 3 villages 

(Barrow, Wainwright, and Kaktovik), 13 DEW radar sites and 

the extensive but spatially restricted infrastructure associated 

with oil and gas extraction activities. Seasonal fish camps 

and whaling villages are scattered along the coast and barge 

landing sites are common adjacent to the villages and oil and 

gas sites. Native Inupiat utilize the coast and nearshore waters 

extensively for subsistence hunting, fishing, and trapping.

Shore protection structures, primarily sand bags and 

rock-filled gabion revetments, discontinuously front the 

bluffs in the villages and at some oil and gas developments. 

Buildings and municipal infrastructure are located within 

several hundred meters of the coast and many primary roads, 

commonly artificially elevated, run along the coast behind 

the primary berms. Sand and gravel mining in the nearshore 

littoral environment around the villages, particularly Barrow 

and DEW sites was common practice historically, but has for 

the most part ended (Jorgenson, 2011).

The first large-scale development in the region began in 

the 1950s with the construction of the Distant Early Warning 

(DEW) Line system. Thirteen sites were built on the Arctic 

coast between Icy Cape and the U.S. Canadian border. Most 

sites were deactivated in the early to late 1960s, however, 

several sites were rebuilt as North Warning System sites 

(Wainwright, Barrow, Lonely, Oliktok, Flaxman Island, Barter 

Island). Only Barrow, Oliktok, and Barter Island are still 

active. The sites produced large amounts of hazardous waste. 

Several of the sites are now threatened by coastal erosion and 

clean-up and remediation are presently underway. The landfill 

at Barter Island was relocated landward in the late-2000s 

although some I-beams and structures previously emplaced to 

protect the old landfill remain in the nearshore environment. 

Remnant gravel pads and airstrips remain at most of the 

abandoned locations.

Coastal development associated with oil and gas activities 

started in the late 1960s with the discovery of the Prudhoe 

Bay fields in 1968. Numerous exploration wells drilled in the 

1970s are scattered across the landscape and are becoming 

increasingly vulnerable to coastal erosion. Several causeways 

and artificial islands have been constructed along the coast 

near Prudhoe Bay and gravel pads and roads supporting 

development facilities are widespread. Few of the production 

sites sit right on the coast, however where present, significant 

modification to the coasts and beaches have occurred.

The warming of the Arctic and decline in the extent of 

summer sea-ice is leading to an increase in both commercial 

and recreational shipping traffic in the region. Development of 

offshore oil and gas leases in the Chukchi and Beaufort Seas is 

also intensifying. The combination of these two activities may 

result in considerable coastal development along the Arctic 

coast in the near future.

Planned Updates 

During the course of this study, two additional regional 

shoreline data sets, circa-1979 Alaska High Altitude Photography 

and 2009–2012 high-resolution coastal lidar surveys, were 

identified. They are currently being processed and will be 

incorporated into the shoreline change data base and analysis and 

released as an update to this study when completed. The USGS 

typically to revises and update rates of shoreline change every 5 

to 10 years, or when new data sets are identified and acquired. 

Therefore, this report and associated data are a work in progress. 

The revision interval will depend on the availability of new 

shoreline data and technological advances. Continued monitoring 

of shoreline change is vital in the coming decades as the dynamics 

of the coastal environment that lead to beach erosion (for example, 

sea-level rise, storms, and waves) are likely to change with 

changing climate.

Acknowledgments

This report was made possible by the hard work and 

generous cooperation of many individuals. We thank Adam Bode 

of the National Oceanic and Atmospheric Administration (NOAA) 

for providing digital historical shorelines and scans of selected 

NOAA topographic sheets (T-sheets), and David Doyle (NOAA) 

for providing datum corrections so that T-sheets could be rectified 

before they were digitized by the U.S. Geological Survey. Karin 

Ohman, Ben Norris, Lynne Harden, and Brian Spear provided 

technical support. Bretwood Higman (Nuka Research and 

Planning), Jennifer Jenkins (U.S. Fish and Wildlife Service) and 

Tom Lorenson (USGS) provided reviews of an earlier version of 

this manuscript. Finally, we acknowledge Drs. Erk Reimnitz and 

Peter Barnes, formerly with the U.S. Geological Survey, for their 

pioneering efforts studying and mapping coastal change along 

Alaska’s Arctic coast.

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Publishing support provided by the U.S. Geological Survey

 Science Publishing Network, Tacoma Publishing Service Center

For more information concerning the research in this report, contact the

Director, Pacific Coastal and Marine Science Center 

U.S. Geological Survey 

Pacific Science Center 

400 Natural Bridges Drive 

Santa Cruz, CA 95060 

http://walrus.wr.usgs.gov/
Gibbs and Richmond—National Assessment of Shoreline Change— Historical Shoreline Change Along the North Coast of Alaska—Open-File Report 2015–1048

ISSN 2331-1258 (online)

http://dx.doi.org/10.3133/ofr20151048