The Alaska Earthquake 

March 27, 1964 

Effects on Communities 

Homer 

GEOLOGICAL SURVEY PROFESSIONAL PAPER 542-D 
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THE ALASKA EARTHQUAKE, MARCH 27, 1964: 

EFFECTS ON COMMUNITIES 

Effects of the Earthquake 

Of March 27, 1964 

In the Homer Area, Alaska 

By ROGER M. WALLER 

With a Section on 

BEACH CHANGES ON HOMER SPIT 

By KIRK W. STANLEY 

A description of the damage caused by landmass 

subsidence, earthflows, landslides, seiche waves, 

and submarine landslides resulting from the 

earthquake in the Homer area, Alaska 

GEOLOGICAL SURVEY PROFESSIONAL PAPER 542-D 
UNITED STATES DEPARTMENT OF THE INTERIOR 

STEWART L. UDALL, Secretary 

GEOLOGICAL SURVEY 

William T. Pecora, Director 

UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON 1966 

For sale by the Superintendent of Documents, U.S. Government Printing Office 

Washington, D.C. 20402 - Price 65 cents (paper cover) 
THE 

AI ... ASKA EARTHQUAKE 

SERIES 

The U.S. Geological Survey is publishing the results of 

investigations of the Alaska earthquake of March 27, 1964, 

in a series of six professional papers. P~ofessional Paper 

542 describes the effects of the earthquake on communities: 

Anchorage ( 542-A) , Whittier ( 542-B) , Valdez ( 542-C), 

Homer ( 542-D) ; other chapters are in preparation on 

Seward, Kodiak, and several smaller communities. Succeeding professional papers will describe the regional effects of 

the earthquake; the effects on the hydrologic regimen; the 

effects on transportation, communications, and utilities; and 

the history of the field investigations and reconstruction 

effort. 

CONTENTS 

Page Page Page 

Abstract _____________________ D1 Effects-Continued Beach changes-Continued 

Introduction __________________ 1 Hydrologic effects _________ D14 Subsidence and postearthPersonal observations __________ 3 Immediate effects _____ 15 quake changes __________ D22 

Effects of the earthquake _______ 5 Long-term effects _____ 16 Berm development and 

General effects and damages_ 5 

Ground water_ ________ 16 beach-face recession_ 23 

Quality of water_ _____ 18 Material supply and 

Geologic effects on the main- Seismic history and conclusions __ 18 transport_ __________ 24 land ___________________ 6 Beach changes on Homer Spit, by Shore protection works ____ 25 

Effects on Homer Spit _____ 7 Kirk W. Stanley _____________ 20 Tidal inlets _______________ 27 

Submarine landslide ___ 10 Introduction ______________ 20 Summary ________________ 27 

Subsidence ___________ 13 General setting ___________ 20 References cited ______________ 27 

ILLUSTRATIONS 

PLATE 

1. Map showing topographic and bathymetric features at end of Homer Spit ________________ In pocket 

1. Maps of Alaska showing 

Homer area ____________ _ 

2. Map of the Homer area ___ _ 

3. Damage to Inlet Inn HoteL_ 

4. Postearthquake erosion at 

Munson Point __________ _ 

5. Fracture pattern on bluff at 

Bluff Point _____________ _ 

6. Photomosaic of Homer Spit 

at high tide on August 8, 

1964 __________________ _ 

7. Preearthquake aerial photograph of Homer Spit ____ _ 

Page 

vi 

D2 

5 

6 

6 

9 

9 

FIGURES 

8. Land's End Hotel raised 

above high-tide leveL ___ _ 

9. Effects of high tide on Homer 

Spit_ __________________ _ 

10. Offshore profiles at end of 

Homer Spit ____________ _ 

11. Fathometer profiles off the 

end of Homer Spit ______ _ 

12. Profiles of Homer Spit showing differential subsidence_ 

13. Hydrographs of wells showing ground-water effects __ 

14. Index map of Homer Spit__ 

TABLES 

Page 

D9 

10 

11 

12 

13 

16 

20 

Page 

15. Map showing high-water line 

comparison_____________ D21 

16. Shoreline west of Homer 

Spit__ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 21 

17. Diagram of beach-face reces- sion__ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 22 

18. Postearthquake frontal berm__ 22 

19. Beach-face recession_______ 23 

20. Modified groin_ _ _ _ _ _ _ _ _ _ _ _ 24 

21. Erosion, lee side of groin____ 24 

22. Accretion, lee side of groin__ 25 

23. Beach protection_ _ _ _ _ _ _ _ _ _ 25 

24. Bar development at a tidal 

inlet entrance___________ 26 

Page 

1. Bench-mark altitudes____________________________________________________ D13 

2. Log of well 120 _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 14 

3. Summary of earthquake history near Homer________________________________ 19 

v 
VI 

INDEX MAP 

~ ope Ninilchik .·· 

HOMER 

Point Bede 

Elrzobet 

10 0 10 MILES 

59° ~---------L--------------------------------~L-------------------~ 

Base map from U.S. Army Map Service, 

1:1000,000 series; Anchorage, 1951-53 

and Kodiak, 1952 

1.-Maps of .Alaska showing Homer area. 
THE ALASKA EARTHQUAKE, MARCH 27, 1964: EFFECTS ON COMMUNITIES 

EFFECTS OF THE EARTHQUAKE OF MARCH 27, 1964, IN THE HOMER 

AREA, ALASKA 

The March 27, 1964, earthquake shook 

the Homer area for about 3 minutes. 

Land effects consisted of a 2- to 6-foot 

subsidence of the mainland and Homer 

Spit, one earthflow at the mouth of a 

canyon, several landslides on the 

Homer escarpment and along the sea 

bluffs, and minor fissuring of the 

ground, principally at the edges of bluffs 

and on Homer Spit. Hydrologic effects 

consisted of at least one and possibly 

t•wo submarine landslides at the end of 

the spit, seiche waves in Kachemak 

Bay, ice breakage on Beluga Lake, sanding of wells, and a temporary loss of 

water in some wells. 

Seismic damage to the community 

was light in comparison with that 

of other communities closer to the 

epicenter. One submarine landslide, 

however, took out most of the harbor 

breakwater. The greatest damage wa·s 

due to the subsidence of the spit, both 

tectonically ( 2-3 ft) and by differential 

compaction or lateral spreading (an 

additional 1-4 ft). Higher tides now 

flood much of the spit. The harbor and 

dock had to be replaced, and buildings 

on the end of the spit had to be elevated. 

Homer is located at the southern 

tip of the lowland part of the 

J(enai Peninsula in south-central 

Alaska (fig. 1). The lowland lies 

west of the J(enai Mountains ahd 

east of Cook Inlet. This paper 

deals with the earthquake effects 

in the general area along the shore 

of J(achemak Bay from Diamond 

Creek on the west to Fritz Creek, 

By Roger M. Waller 

ABSTRACT 

Protection works for other buildings 

and the highway were needed. These 

works included application of fill to 

raise the highway and parts of the spit 

above high tides. Reconstruction costs 

and disaster loans totaled about $2% 

million, but this amount includes added 

improvement costs over preexisting 

values. 

Homer Spit in particular and the 

Homer area in general rank as areas 

where precautions must be taken in selecting building sites. The hazards of 

landslides, earthflows, compaction and 

submarine slumping-all of which 

might be triggered by an earthquakeshould be considered in site selection. 

In plan, Homer Spit resembles a scimitar with its curving blade pointed seaward. It is about 4 miles long and as 

much as 1,500 feet wide. The spit is 

composed largely of gravel intermixed 

with some sand. 

After the earthquake and the resulting tectonic subsidence and compaction. 

much of the spit was below high-tide 

levels and consequently flooded periodically. The entire beach face has retreated. ~Iuch of the material eroded 

INTRODUCTION 

about 6 1niles east of Homer. 

Homer is about 160 miles southwest of the epicenter of the earthquake of March 1964. 

Immediate field observations 

were limited because the writer's 

primary assignment was to Anchorage. Early observations in 

the Homer area were made by 

U.S. Geological Survey colleagues 

from the beach has been redeposited to 

form a new storm or frontal berm, locally migrating around buildings and 

covering roads. Beach recession of 10-

15 feet is probably the overall average; 

maximum recession 1 year after the 

earthquake was 56 feet along one 

limited section of the distal end of the 

spit. 

Subsidence of the mainland has 

caused accelerated erosion of the 

beaches and headlands that have beenand are--source areas for the material 

deposited on Homer Spit. The resulting 

increased supply of gravel and sand 

probably will cause the spit to widen 

gradually on the Cook Inlet side. Similarly, the new frontal berm will probably grow to a height sufficient to prevent overtopping by all but the larger 

storm swashes. The nature of shore 

processes on the spit has not been materially altered by subsidence, but the 

rates of erosion and deposition have 

been accelerated. The lasting effect of 

subsidence (excluding flooding) will be 

enlargement of the beach on the Cook 

Inlet side and gradual wasting of the 

beach on the bay side of the spit. 

Reuben J(achadoorian and George 

Plafker. Special thanks are due 

to the numerous people at Homer 

who provided their observations 

of the earthquake and to Mr. Al 

Billings, project engineer, U.S. 

Army Corps of Engineers, Homer, 

who helped make the offshore 

fathometer traverses. 

D1 
R.14 W. R.13 W. 

11 

T. 

Gr-----------~~~----=-~----------~r-~~------r-----. 

S. 

EXPLANATION 

u 

D 

Vertical fault 

U, upthrown side; D, downthrown side 

0 49 

Well used for water-level observations 

'-. 

Landslide or earthflow 

Arrow shows direction of movement 

Observed 

~ 

sea wave 

Arrow shows direction of travel 

X 

Areas of accelerated erosion 

~ KACHEMAK 

COOK IN~ y 

1 0 1 MILE 

2.-Map of the Homer area showing slide areas, beach erosion points, and locations of wells. 

BAY 

N 

Boat 

t1 

~ 

> t-t 

> U1 

~ 

tr:l 

> l:d 

8 

E 

~ P1 

tr:l 

~ 

> l:d 

0 

p:: 

t,:) 

'-1 

1-' 

~ 

0) 

..... 
Most of the residents of the 

small town of Homer were settling 

down for the evening meal at 5 :36 

p.m. (Alaska standard time) on 

Good Friday, March 27, 1964. 

Several people were still out at the 

end of the Homer Spit which extends 4 miles into Kachemak Bay 

(fig. 2) . The weather was mild ; 

there was an overcast and nearfreezing temperatures and light 

snow was falling. A thin snow 

cover lay over most of the land. A 

high tide of 19.4 feet was ebbing 

to a low which would occur at 

about 7 :30 p.m. 

To some people the first indication of something happening was 

the loss of electric power, but most 

persons realized that there was an 

earthquake when they felt the initial shock at about 5 : 37 p.m. As 

the shock waves continued, they 

realized this was an exceptionally 

severe earthquake. Estimates of 

the length of time of earth movement ranged from 1 to 5 minutes. 

Mr. Ralph Cowles, the mayor of 

Homer, stated (Grantz and others, 

1964, p. 24) "that 'the total time 

of the tremor was from 2 to 2% 

minutes and that its motion was 

'wavy' and east-west." Mr. Paul 

Gardiner reported 2- to 3-foot 

ground waves moving east-west 

near the airport, and Mr. and Mrs. 

D. P. Lowcock sensed east-west 

motion on Munson Point. Many 

people stated, however, that the 

principal direction of movement 

was north-south and that the 

movement was so violent that 

standing unsupported was impossible. Mr. and Mrs. Albert Greer 

reported ground waves coming 

two at a time downhill from north 

to south. In general, the ground 

movement "\Vas reported to be a 

gradual buildup of a rolling motion to a peak intensity, then a lull, 

and then another buildup to a peak 

797-'974 Q-i66-3 

EFFECTS IN THE HOMER AREA 

PERSONAL OBSERVATIONS 

before suddenly stopping. Mrs. 

Leo Rhodes, Mr. and Mrs. Vic Nelson, and Mrs. Gus Weber remarked on the great silence thaJt:. 

prevailed during lulls in the earthquake, in contrast with the rumbling, cracking, and popping 

noises reported by Mr. Karl Baier, 

Mrs. Rhodes, the Nelsons, and 

others as prevalent during the 

violent-motion phases of the 

quake. 

The violence of earth movement 

was noted by several witnesses. 

Mr. Tex Sharp, in his apartment 

when the quake occurred and the 

power failed, tried to cross the 10 

feet from his apartlnent door to 

his place of business, the Waterfront Bar and Dining Establishment. He was unable to cross for 

about 4 minutes. 'Vhen the shaking stopped, he entered the bar, 

in his bare feet, and found his 

stock of bottled goods and glassware almost 'totally destroyed. On 

East Road near Fritz Creek, Mr. 

l{arl Baier was thrown to the 

ground and was unable to rise for 

some time. Near the airport, Mrs. 

Leo Rhodes and Mrs. Vic Nelson 

were unable to walk without support during the violent phases of 

the quake; Mr. and Mrs. D. P. 

Lowcock reported that they and 

their dog were thrown to the 

ground by the force of the motion 

on Munson Point. 

Animals, too, were affected. 

Dogs, sheep, and geese were 

thrown to the ground. Mrs. Gus 

Weber reported that two moose 

ran from the woods into a clearing 

where they "jumped, bucked up 

and down like horses, reared up 

on their hind legs and ran back 

and forth as the earth moved in 

a 11 directions." These experiences 

suggest that the quake had an inD3 

tensity of between VII and VIII 

on the Modified Mercalli scale. 

At the height of the quake, earth 

fissures formed and closed in many 

parts of Homer and the vicinity. 

Near the airport, according to 

J\{rs. Vic Nelson, the ground and 

snow cover "cracked like lightning," opening and closing. Mr. 

and Mrs. Albert Greer reported 

that fissures formed in the ground 

"with a cracking noise." Mr. 

Karl Baier saw a field crack in a 

checkerboard pattern and a 6-inch 

fissure traverse the ground and 

split a spruce tree. On Homer 

Spit, Mr. Glen Sewell (Grantz 

and others, 1964, p. 24) watched 

a fissure form on the oceanside of 

the spit and travel toward him. 

The ground split under his truck 

and between his legs, opening up 

to about 12 inches and allowing 

gravel to roll in. The fissure extended, splitting the concrete floor 

of the Porpoise Room. Paved 

roads were fissured in various 

places throughout the Homer area, 

but significant patterns and extensions of fissures into adjacent 

unpaved areas have not been 

recorded. 

Exceptional sea waves, both in 

Cook Inlet and in Kachemak Bay, 

were seen by various observers. 

Inasmuch as the waves were observed within 5-10 minutes after 

the quake, the waves clearly did 

not originate near the epicenter, 

160 miles distant. On the other 

hand, some reported waves apparently came in from the open ocean; 

hence it cannot be assumed that 

all of the waves were seiches although waves that traveled approximately at right angles to the 

shores of Cook Inlet 1nay have 

been seiches. Submarine slumping occurred off the tip of Homer 

Spit. The possibility of larger 
D4 

scale slumping or landsliding, or 

both, in uninhabited parts of Cook 

Inlet cannot be disregarded ; however, there is no direct evidence 

that such sliding and slumping 

occurred to cause the sea waves. 

In short, the origin of the waves 

remains unexpl,ained. The reported wave patterns are shown 

diagrammatically on figure 2. 

Eyewitnesses reported that 

wave heights and patterns were 

markedly different in Cook Inlet 

and in l{achemak Bay. For example, while returning to Homer 

:from the spit, shortly after the 

earthquake, Mr. Glen Sewell 

noticed a wave "rolling in from 

the ocean" about a mile offshore. 

Mr. and Mrs. D.P. Lowcock also 

saw a wave which probably was 

the same one seen by Mr. Sewell. 

After the ground motion stopped, 

the Lowcocks looked offshore and 

saw a wave "rolling in from Seldovia." It was perhaps a mile 

long, cresting, and alined approximately northwest to southeast. 

They also observed another wave 

coming directly northwestward 

toward them. It was shorter and 

did not appear as high, but it 

was cresting also. The two wave,g 

gave the appearance of an "inverted V," but they were not joined 

(fig. 2). 

The wave coming from the 

ocean was probably the same one 

observed also from downtown 

Homer. It reportedly (Mr. Velton Cason, oral commun., 1964) 

came in as a 9-foot swell about 5 

minutes after the beginning of the 

earthquake motion, and there was 

a withdrawal of water on the 

beach before it struck. 

Within Kachemak Bay, wave 

action developed also. Mrs. Fitzgerald, on East Road, reported 

that it looked as if "the land was 

being shoved under the bay" because of the curious breaking and 

surging of the waves on the tidal 

ALASKA EARTHQUAKE, MARCH 27, 1964 

flats. Her family had counted 

seven waves rolling in when their 

attention was diverted due to a 

"harder part of the shock." She 

reported that others counted 14 

waves in the bay. 

The U.S. Coast and Geodetic 

Survey ( 1964a, p. 82) reported 

from news excerpts that "Ten-foot 

waves at 2-minute intervals occurred at about the same time the 

ground shock was felt." This report agrees with Stanley's ( 1965) 

statement that the waves immediately after the earthquake were 

9 feet high in Cook Inlet and 4 feet 

high in K·achemak Bay. 

Evidently a series of waves was 

immediately generated in the bay. 

AU except one of the observed 

waves were parallel to the north 

shore. Probably the sa.me waves 

were noted by J. M. Moss (written 

commun., 1964) on the south shore 

at Peterson Bay (fig. 1) as the 

"Tide came and went for at least 

15 hrs." 

ICachadoorian ( unpub. data, 

Apr. 1, 1964) recorded a fisherman's report of an estimated 50-

foot wave seen after dark off the 

south tip of Kenai Peninsula (lat. 

59°07', long. 151 °35') ; the wave 

appeared to emit geysers or smoke. 

A 28-foot wave hit Perl Island, 35 

miles south of Seldovia (fig. 1) at 

8 :40 p.m. (H. D. Hess, written 

commun., 1964). Wave action in 

the general area was -also recorded 

by ~Tim Reardon, Alaska Departlnent of Fish and Game at Homer, 

in his radio log (written commun., 

1964) as follows: At 10 :25 p.m. 

I\1arch 27 Seldovia radio reported 

the "tide slmvly coming in." This 

rise was 3 hours before the high 

tide was due at 1 :39 a.m. At the 

same time the radio station at 

l{asitsna Bay (first bay east of 

Seldovia, fig. 1) reported that 

\Yater came in at 40 miles per hour. 

At 10:28 p.m. Seldovia radio reported "tide coming in :fast," and 

at 10:37 p.m. "water going back 

out." At 11 :15 p.m. Seldovia radio reported "harbor damaged," 

and at 11 :17 p.m. "water coming 

up fast, estimate 18 feet, going to 

higher ground." At 11 :21 p.m. 

Seldovia radio said "Water receding" and at 11 :55 p.m., "Water 

down to 12 feet, starting up." 

Meanwhile Perl Island radio reported a second wave (30 feet) at 

11 :40 p.m. At 1 :40 a.m. March 28 

Seldovia radio noted the "tide 

reached normal high, receding 

normally." Perl Island radio reported a third wave ( 30 feet) at 

2 :30 a.m. At 2 :48 a.m. Seldovia 

radio again reported "water up to 

25 feet and receding." 

These records of wave action 

suggest that a tsunami could have 

arrived about 10.:30 p.m. at Seldovia, a second at 11 :18 p.m. before the normal high tide arrived, 

and a third at 2 :48 a.m. after the 

high tide. Halibut Cove (wide 

bay almost due east of the end of 

Homer Spit, fig. 1) also reported 

a tide of 24 feet at 11 :35 p.m. 

which could have been the same 

one that hit Seldovia at 11 :18 p.m. 

If these wa.ves were tsunamis, 

Homer would have been hit by 

them also. 

There is some evidence that 

Homer did indeed experience 

tsunamis. A. G. Green reported 

(written commun., 1964) that a 

20-foot wave arrived about 9 :30 

p.m. at Homer. Mr. Jim Reardon 

reported (H. S. Thompson, oral 

commun., 1964) overwash at the 

base of the spit in the late evening. 

The Inlet Courier [Homer] (Mar. 

30, 1964) also reported that at the 

end of the Homer Spit "Water 

rose in surges beyond the normal 

tide heights and covered the floor 

in the new Porpoise Room. It 

rose to a height of 4 feet 

in the Salty Dawg * * * and also 

covered the floor * * *" of the 

Land's End Hotel. 
EFFECTS IN THE HOMER AREA 

The long single wave that was 

seen to approach Homer from the 

southwest on the oceanside of the 

spit may have originated from 

submarine slumping, p o s s i b 1 y 

along the coastline near Seldovia ; 

it may have been an oscillatory 

wave (seiche) ; or it may have 

been the response of the ocean to 

sudden lowering of the Kenai 

Peninsula and the floor of 

Kachemak Bay. 

The complex pattern of smaller 

waves seen in Kachemak Bay perhaps had no relation to tsunamis. 

More probably these waves were 

generated by horizontal and vertical movement of the land during 

the earthquake. Tectonic subsidence also doubtless contributed 

to the development of the waves 

in the bay. Alternatively-or additionally-submarine landslides 

may have contributed to the 

Kachemak Bay waves. Slumping 

along the front of the delta lying 

off Grewingk Glacier (fig. 1) is a 

likely source of energy for these 

waves. Tectonic movement probably was the cause of many or 

even all of the wave phenomena 

observed at Homer. Furthermore, the larger waves that appeared at intervals probably resulted when the oscillating waves 

reinforced one another, as is 

known to happen. It is noteworthy also that most waves beThe effects of the earthquake, in 

the Homer area were light compared to the catastrophic effects 

experienced elsewhere in Alaska. 

These effects will be considered in 

four classes: (1) general effects 

and damage to structures, (2) 

geologic effects on the mainland, 

(3) effects on Homer Spit, and 

(4) hydrologic effects. There is 

necessarily some overlap and repetition in the discussion. 

EFFECTS OF THE EARTHQUAKE 

came visible only when they 

traversed the shoals that extend 

far out from the north shore of 

Kachemak Bay and Cook Inlet. 

But the alternative possibilities 

must be considered as well. 

In any event, damage from 

waves was negligible at Homer 

for two reasons : (1) the incident 

waves were small, and (2) the 

larger waves impinged on the land 

when the tide was low and an 18- 

foot tidal freeboard protected the 

town. If larger waves occur 

when the tide is high during an 

earthquake in the future, the 

damage may be appreciableespecially on Homer Spit. 

GENERAL EFFECTS AND 

DAMAGES 

One of the first effects of the 

shock noticed in Homer was loss 

of electric power. It was, however, restored in 17 minutes when 

a. standby diesel plant went into 

operation. Long-distance telephone service was temporarily disrupted, but local service continued. 

The U.S. Federal Aviation 

Agency communications cable under Beluga Lake (fig. 2) was 

broken. Buildings throughout the 

or only minor damage. At least (fig. 3) and concrete-slab floors 

five chimneys were knocked down, were cracked or fissured. Dishes 

a few plate-glass windows were and glassware were broken in 

broken, and several foundations many homes and business estabarea were severely shaken but sur3.-Damage to foundation walls of the Inlet Inn Hotel. Unreinforced concrete- vived, in general, with no damage block construction. 
D6 ALASKA EARTHQUAKE, MARCH 27, 1964 

incompetent nature of the bedrock 

and of the thin layer of soil that 

overlies the rock. The bedrock is 

described by Barnes and Cobb 

(1959, p. 224) as "* * * moderat,ely indurated sand, silt and clay 

in generally thin and intergmaded 

beds and lenses * * *," material 

that might readily yield to gravity 

when disturbed by seismic shocks. 

The landslide (easternmost in 

sec. 1, fig, 2) debris covers an area 

about 600 feet long and 100 feet 

wide. The material that slid 

stood previously as a promontory 

along a bluff eroded into the I<enai 

Formation. The slide area is near 

a fault in sec. 2 mapped by Barnes 

and Cobb (1959, pl. 18), but there 

is no evidence that this fault 

4.-Postearthquake erosion at Munson Point as of April 13,lM. About 3 feet of the nloved in 1964. Landslide hazoverhanging vegetal mat attests to recent erosion of the underlying glacial till ards exist in situaas a result of higher water levels relative to land. tions near Homer-and indeed 

anywhere that promontories exlishinents. The most severe damage, however, was to the small-boat 

harbor near tlie end of Hoiner 

Spit. There the outer seawall 

largely disappeared as a submarine slide removed its fiouild a t' ions. 

few small buildings at the distal 

encl of the spit were overturnecl 

by falling into another slumped 

area. Private individuals experienced property losses of abot~t 

$1,040,000, the sum of 40 applications for Small Business Administration disaster loans (Inlet 

Courier, June 19,1964). Total reconstruction costs for Homer are 

about $21/2 million. That sum, 

ho~~ever, includes improvement of 

facilities-especially the smallboat harbor-and is not a reflection of actual damage alone. 

Potential suffering and losses 

that might have resulted from food 

shortages because of destructioil of 

highway bridges bet~~een Anchorage and Homer mere averted by 

airlifts. In particular, airlifted 

fodder tided over the needs of cattlemen caught by tlie earthquake 

wit11 a short supply of feed for 

their animals. 

GEOLOGIC EFFECTS ON 

THE MAINLAND 

Changes brought about by the 

earthquake on the mainland at 

Horner are of interest principally 

because they illustrate the types 

of disruption that under other circumstances have been dan~aging- in 

other areas. The most far-reaching effect was tectonic snbsidence 

that lowered illost of the ICei~ai 

Peninsula, a few feet relative to sea 

level (Gmntz ancl others, 1964, fig. 

3). This subsidence proved to be 

most clamaging on Homer Spit (p. 

D7) but had little effect on the 

mainland otlther than to expose 

fresh areas to wave erosion along 

sea cliffs in the Homer area (fig. 

4). 

Only one landslide and one 

earthflow of any consequence occurred near Homer, ht11 in sec. 1, 

T. 6 S., R. 13 IV. (fig. 2). This 

fact is surprising in view of the 

tend out from precipitous bluffs 

and cliffs. Bluff Point, north of 

Hoiner (fig. 2) is an example. A 

field st8tion of the U.S. Bureau 

of Land Management is situated 

about 50 feet from the edge of a 

700-foot bluff. Numerous fissures 

(fig. 5) developed during the 

1 50 - 0 50 FEET 

- 

EXPLANATION 

Fissure m 

Upper edge 

of bluff 

5.-Sketch map of the ground-fissure pattern at the U.S. Bureau of 

Land Management field station near 

Homer. Traced from field compilation on aerial photograph by 

K. A. Roddy, U.S. Bureau of Land 

Management, May 1, 1964. 
EFFECTS IN THE HOMER AREA 

earthquake on the surface above 

the bluff, some of them several 

inches wide. A few could be 

traced about 20 feet down the bluff 

face. One earth fissure extended 

across the area of a field-station 

building and cracked the basement 

floor of the structure. Areas 

above and close below promontories where earthslides might occur must remain suspect as sites 

for any building. 

An earthflow occurred in the 

first canyon southwest of the landslide (fig. 2) ; it created a jumbled 

mass of uprooted trees, mudflows, 

rafts of soil and vegetation, and 

collapsed ground. The area of 

disturbed ground is about 1,000 

feet long and has a maximum 

width of about 400 feet. Horizontal displacement of material 

within the flow, however, probably did not exceed 200 feet. The 

material involved consists mainly 

of silt, some fine sand, and occasional layers of flat pebbles. The 

head of the flow is near the apex 

of an alluvial fan at the mouth of a 

small canyon occupied by an intermittent stream. Water was seeping from both disturbed and undisturbed material on June 21, 

1964, and may have contributed to 

causing the flow. 

Two large landslides in the 

L4nchor River valley north of 

Homer (fig. 1) were seen from the 

air, and other fresh-looking scars 

appear on aerial photographs of 

the north shore of Kachemak Bay, 

taken after the quake. But 

whether the slides that cauwd these 

features were the result of the 

earthquake is not known. 

The entire Homer area appears 

to be one where steep slopes, the 

fine texture and weak consolidation of the rocks of the Kenai Formation, and the common condition 

of saturation with water favor 

landslides and earthflows. These 

hazards should be considered when 

locating sites for building, especially because the shaking incidental to earthquakes tends to ~veaken 

the cohesion of the rock maherials 

and to cause them to move under 

the influence of gravity. 

Ground fissuring occurred in the 

Homer area, but as in most other 

parts of south-central Alaska it 

was probably not caused by deep 

bedrock faulting. In general, the 

fissuring was of minor importance 

in the Homer area, except for the 

fissures occurring at the U.S. 

Bureau of Land Management station and on Homer Spit. Most of 

the fissures formed on the spit 

probably were caused by the submarine landslides or compaction. 

Other fissures were reported at the 

mouth of Thurston Canyon just 

west of Fritz Creek in the northeast corner of the study nrea, but 

were not checked in the field. 

These fissures were reportedly so 

large that a Shetland pony fell 

into one several days after the 

earthquake and could not, get out. 

No fissures formed on the mudflats of the Palmer Creek tidal 

area near Munson Point (fig. 2) 

although elsewhere in southcentral Alaska such sites were 

cllaracterized by extensive fissuring. Perhaps the depth of alluvium, estimated at about 200 feet, 

was not sufficient or the distance 

from the epicenter as too great 

for fissuring to develop during the 

earthquake. Fissuring of unconsolidated material from a seismic 

wave is a functioil of distance, 

topography, and geologic conditions, but thickness of the material 

probably is important also. 

EFFECTS ON HOMER SPIT 

The commercial and industrial 

center of the community is on 

Homer Spit. The port for both 

large vessels and small boats is 

there, and the spit is occupied by 

a hotel, food-processing plants, 

restaurants and bars, and other 

places of business. The entire spit 

subsided as a result of the earthquake. Part of the subsidence \%-as 

tectonic and part-especially at 

the seaward end-was probably 

the result of compaction of the uncoi~solidsted gravel that makes up 

most of the spit. Total subsidence 

at the end of the spit by June 1965 

is reported by the U.S. Coast and 

Geodetic Survey (oral commun., 

1965) to be 5.9 feet. In addition 

to extensive damage by flooding 

caused by subsidence, a submarine 

slide removed most of the seaward 

side of the small-boat harbor. The 

heaviest financial losses at Homer, 

therefore, occurred as a result of 

earthquake effects on the spit. 

In addition to damage to manmade structures, the subsidence 

caused a change in the physical 

relations between the spit and the 

water surrounding it. As a result, 

the shape of the spit cllanged and 

beach stability was disrupted. The 

phenomena relating to beach 

changes on Homer Spit are the 

subject of the section by K. M. 

Stanley (p. D20). The extent of 

high-tide flooding of the spit is 

shown by Stanley (see fig. 15) in a 

pair of maps that contrast dryland exposure on the spit before 

and after the earthquake. The 

devastating flooding on the spit 

immediately after the quake is further illustrated by figures 6 and 7 

(on next page), aerial photographs 

of the spit taken before and after 

the earthquake. 

Some of the specific damage to 

structures caused by the flooding 

may be seen in figure 8 (on next 

page), \\--hich shows the Land's 

End Hotel elevated on jacks to 

raise it above the postearthquake 

high-tide level. Figure 9 (p. D10) 

shows other scenes of the effects of 

the high tides. During the high 

tide of about 19 feet that occurred 

the night following the earth- 
GPhotomosaic of Homer Spit at high tide on August 8, 

7.-Preearthquake aerial photograph of Homer Spit. 

D8 
lared photographs by U.S. Bureau of Land Management. 

1 quake, material salt-water damage It was apparent that, in addition (Federal Reconstruction and Demas done to the hotel, to the Por- to repairs, rei~ledial measures were velopment Planning Commission I poise Room, the Salty Dawg needed to avoid future storm- for Alaska, 1964, 13. 80). The reSaloon, two seafoocl-processing Imve damage as x-ell as damage placement of the Homer dock 

I plants, and the Standard Oil Co. from normal high tides. Such ($195,000) and a small-boat hartank farm. measures were started immediately bor ($964,200), wit11 more than 

I Fortunately the mid-April high by some concerns, \rhereas otllers double the capacity of the old 80- 

I tides were ilot accompanied by awaited aid from the Government, boat harbor, mere the principal 

strong winds, and most of the through the Federal Disaster Act, costs, and construction of bath 

1 facilities survived the first on- authorized under Public Law 81- was uilderway by November 1964. 

slaught with only salt-water dam- 875. Ss of August 30, 1964, the Adverse wind and tide conditions 

age. Some structures that could Office of Emergency Planning had did not occur until late 1964, when 

not be raised on jacks were pro- authorized reconstruction projects wind-driven ice "* " * knocked 

tected %,gainst further flooding by totaling $1,565,000 to replace or out part of the new pier now under 

hurriedly built embankments. The rehabilitate public facilities dam- construction and did further damonly land not inundated at the end aged by the earthquake and tides age to the * * * old pier * * *." 

I of the spit was the storm berm 

around the perimeter of the spit, 

older storm berms of the beach, 

aid the spoil pile from the original dredging of the small-boat 

1 harbor (fig. 6). The asphaltcovered highway was eroded away 

near the base of the spit by norI ma1 wave action at high tide. The 

I dock had only about 1 foot of freeboard, the oil tanks were in ~~ater 

as much as 6 feet deep, water 

flowed through the mindorr-s of the 

Salty Dawg, one small ~~arel~ouse 

broke and ''Ie 8.-Land's End Hotel jacked up 8 feet to avoid inundation by high tides. View 

farm this in- from Homer dock looking west. View during first 20-foot tide. Middle part of 

dicated differential subsidence. hotel not yet raised. 

I 
Dl0 ALASKA EARTHQUAKE, MARCH 27, 1964 

9.-Effects of the high tides submerging the end of Homer Spit on April 12, 1964. A, Standard Oil Go. tank farm awash in as 

as much as 6 feet of water. B, Lands End Hotel raised on jacks. 0, Water rose high enough to flow through the wiildows 

of the Salty Dlawg Saloon. D, New storm berm encroaching on spit southwest of the Land's End Hotel. 

(Anchorage Daily Times, Jan. 2, 

1965). A subsequent storm with 

winds of as much as 50 knots from 

the southwest created heavy surf 

whicl~ churned under Land's End 

Hotel, but the only damage reported was to the road (Anchorage Daily Times, Feb. 16, 1965). 

By June 1965 the berm at the end 

of the spit had migrated about 80 

feet. 

SUBMARINE LANDSLIDE 

Available evidence indicates 

that one and possibly two submarine landslides occurred at the distal end of Homer Spit. The loss 

of the small-boat harbor breakwater TT:IS, of course, obvious, but 

\x-lletller only the breakwater slid 

or whether substantial material 

from the spit slid ~~ith i IT-:IS not 

immediately apparent. Indications of another slide were coatained in a report that "The area 

on the shore west of the Salty 

Da~~g collapsed approximately 10 

feet." (The Inlet Courier, Mar. 

30, 1964, p. 1). An accompanying picture showed this "collapse" anti several buildings 

slumped into it. The area was 

covered in a matter of days by a 

new berm (fig. 90) tliat prevented 

observation. 

The writer noticed fissures in the 

area at the end of the spit on April 

12,1964, during observation of one 

of tlle first tidal inundations. The 

sound of air escaping from the 

ground was heard and bubbles 

were seen as the tidewaters overran the spit. The air bubbles occurred in linear patterns near the 

dock (pl. 1). After the tide receded close examinations of the 

surface sho~ved three large fissures 

southwest of Land's End Hotel. 
EFFECTS IN THE HOMER AREA 

Well 

120 

Sea level (MLLW) 

0 

~ ...J 

...J 

~10 

~ 

0 

...J 

w 

Ill 

eli 

~ 20 

0 

I 

1-

<( 

LL. 

z 30 

i 

1-

a.. 

w 

0 

40 

Dll 

EXPLANATION 

Well log 

C, claystone or mudstone; 

G, gravel; S, sand; Si, silt 

Vertical exaggeration X8 

Datum is postearthquake 

mean lower low water 

-- A2-1 

-------------

50 ~ 

...J 

...J 

~ 

~ 

100 g 

w 

Ill 

~-­

w 

w 

150 LL. 

z 

I 

1-

a.. 

200 ~ 

250 

50~~~------~--------~--------~---------L---------L------~-L--------~--------~--------~------~300 

0 500 1000 1500 2000 2500 3000 3500 4000 4500 5000 

DISTANCE, IN FEET FROM SHORELINE 

10.-0:ffshore profiles showing the slope off the end of the Homer Spit. Lines of profiles plotted on plate 1. Data from U.S. 

Army Corps of Engineers. Profile A1 is the easternmost of the two shown on plate 1. 

Other fissures were noted near the 

Alaskan Seafood plant, along the 

road, and near the west shore. 

The fissures on Homer Spit 

were plotted (pl. 1) in their approximate locations. Many fissures were somewhat obscured by 

repeated inundation but, surprisingly, those in vegetated (clune 

grass) areas \Vere still noticeable 

several months later. Grantz and 

others ( 196-!, p. 24) reported that 

''Many of the fractures had vertieal clisplaeement, some as much 

as 8 inches, with the dmvndropped 

side toward the coast," presumably 

meaning both the bay and the 

ocean shoreline~ henee the material was displaced clown ward between the fissures and the closest 

shoreline, a fact which suggests 

lateral spreading. 

The fissures at the end of the spit 

were possibly related to the kno,vn 

797-974 0- 66 - 5 

slip of the brealnvater and the collapse of land west of the Salty 

Dawg Saloon. Offshore bathymetry that might indicate slides 

also became available. The lT.S. 

Army Corps of Engineers made a 

bathymetric. survey in July 196-! 

at and adjacent to the small-boat 

harbor to determine the bottom 

topography and the displacement 

of the breakwater remains. The 

bathymetry (pl. 1) does not extend far enough sea ward to show 

the full extent of the slide nor far 

enough around the end of the spit 

to show the supposed seeond slide. 

It does, however, show the position 

of some of the remains of the 

breakwater. In addition, four 

lines (pl. 1) were run offshore, 

each about 5,000 feet long. Three 

of these profiles are shown on figure 10. The log of test well 120 

is also shown (fig. 10) to indicate 

the seeming coincidence of silty 

zones beneath the spit with offshore bulges or plateaus on the 

bathymetric. profiles. 

Rehabilitation of the Land's 

End Hotel and other faeilities by 

the expenditure of Federal funds 

required that the Scientific and 

Engineering Task Force, established by the Federal Reconstruction and Development Planning 

Commission, evaluate the risk inYol vecl in reeonstruction on the 

spit. The writer supplied data 

(Federal Reconstruetion and Development Planning Commission 

for Alaska, 1964, p. 53) for the 

task force on earthquake effeets at 

Homer and pointed out the potential slide danger. Further study 

of this lutzard was requested. Extension of the Corps of Engineers' 
0 

D12 ALASKA EARTHQUAKE, MARCH 27, 1964 

11.-Fathometer profiles showing the slope off the end of Homer Spit. Lines of profiles plotted on plate 1. Line 6 approximates line A2-1 of figure 10. 

bathyn1etric survey was not feasible at the time, so a portable fathometer (used successfully by 

other Survey geologists in determining subaqueous slides in Kenai 

Lake and elsewhere) was used to 

run a few continuous profiles offshore to try to determine slide 

areas (locations on plate 1). Although the runs ,v,ere hampered by 

the writer'rs inexperience with the 

instrument, the results are believed 

to confirm the presence of another 

slide west of the Land's End Hotel. 

The instrument, which measures 

and continually records the water 

depths on paper, was carried in a 

small metal boat powe.red by an 

outboard motor. The transducer 

was set on the floor of the boat in a 

puddle of water. Experience of 

previous Survey investigators had 

indicated that this is convenient 

and satisfactory for obtaining accurate depth soundings. 

The depth soundings were made 

on August 18, 1964, during low 

tide and a calm sea. Relative tidegage readings on the U.S. Coast 

and Geodetic Survey gage on the 

Homer dock were 23 feet at the 

start of the first traverse and 21.5 

feet at the end of the sixth traverse. The predicted low tide 

preearthquake level of 7.3 feet) 

occurred just at the end of the last 

traverse. Hence, a relative sea 

level of 22 feet was used as an average. The boat was run out an estimated one-half mile, and a line 

bearing was taken on two prominent shore landmarks. The fathometer "\vas turned on when the 

boat reached a preset throttle speed 

of about 3 miles per hour. Therecording of each profile was stopped 

just as the boat touched shore. Although the traverses "\vere .run in 

a straight line, the lengths of the 

traverses could not be determined 

"·ith much accuracy. The profiles 

made by the Corps (pl. 1) were 

not continuous, so detailed correlation with the writer's profiles 

(fig. 11) was not possible. The 

profiles in figure 11 show various 

irregularities in configuration of 

the bottom. Humps that are especially prominent on the steeper 

(profiles 2-5, fig. 11) are interpreted either as recently deposited 

loose material that has slid down 

the slope or as the toes of incipient 

slides represented by the downdropped and fissured land on the 

shore (pl. 1). 

Lack of horizontal control precluded contouring the offshore 

slope in detail, so the Corps of Engineers profile data (pl. 1) was 

used. The upper foreshore has a 

slope of about 22 percent, "\Vhereas 

the offshore slopes range from 6 

to 12 percent. The contours show 

part of a scarp extending northnm>theast and south-southwest 

transversely to the spit. The scarp 

terminates the relatively shallmv 

platform of the Archimandritof 

Shoals (see fig. 14). The spit has 

been built onto this platfonn and 

extends out into the deep entrance 

of the bay. 

Slope failures off the end of the 

spit apparently may have occurred, or started to occur, as a 

downward and outward adjustment-including lateral spreading 

-controlled by the platform scarp 

and the slope of the foreset bed- .. 

ding. Terzaghi ( 1956) indicates 

that subaqueous slides srtart by liq-
:2: 

:J 

1-

<( 

0 

40 

w 30 

> 

0 

co 

<( 

1-

w 

w 

LL... 

20 

uefaction of a water-bearing silt 

layer. Internal hydrostatic pressure can be built up by shock 

waves until relief occurs by lateral 

movement of the water and silt. 

Subsidence and slope failure follows, causing a slump or slide. 

The breakwater slide had the 

added factor of a heavy artificial 

load which contributed to the extended movement of the slide. The 

possible relation of slide planes to 

subsurface silt zones has already 

been mentioned. 

SUBSIDENCE 

An understanding of the cause 

of the subsidence of Homer Spit 

is very important as a guide to 

future construction. If the geologic conditions of areas thalt become compacted during highmagnitude earthquakes can be determined, an informed decision 

can be made on whether or not to 

build in such areas. 

Cmnpaction on Homer Spit is 

indicated by evidence already mentioned. Further evidence confirming that emnpaction or lateral 

spreading, or both, occurred was 

provided by a resurvey of a highway profile. The Alaska Department of Highways had surveyed 

EFFECTS IN THE HOMER AREA 

the spit for a new road shortly before the earthquake. They resurveyed the line within a week after 

the earthquake and found that the 

spit was lower, principally on the 

outer end. A plot of the two surveys is shown on figure 12. The 

line of the profile is along the east 

side of the Spit road except near 

the outer end where it angles toward the dock (pl. 1) . 

The profiles were tied to a bench 

mark near the airport, which is 

considered to have been unaffected 

by compaction. The resurveyed 

profile shows little change at the 

landward end and thus supports 

this conclusion. The teetonic subsidence, of course, lowered the 

bench-mark area as well as the spit 

by about 2 feet. The regional teetonic subsidence increases southeastward toward the hinge zone 

(Plafker, 1965). The subsidenee 

on bedrock at Seldovia is 3.7 feet 

(U.S. Coast and Geod~tic Survey, 

1964b, p. 3) ; hence the teetonic 

subsidence at Homer should increase toward the end of the spit, 

possibly by as much as 1 foot. 

The total amount of subsidence, 

including that resulting from cOinpaction or lateral spreading as 

well as that from tectonic moveDISTANCE, IN THOUSANDS OF FEET 

D13 

TABLE 1.-U.S. Ooast and Geodetic Survey preliminary bench-mark altitudes 

on Horner Spit (based on Ap.ril 1964 

tide series) 

Altitude above mean lower low water (feet) SubsidBench mark ence 

l_ _____ ------------

2_- ----------------- 3 _______ -------------

4_- ----------------- 5_- ----------------- Homer East Base __ . 

Pre- Postquake quake 

21.81 16.97 22. 17 17.25 21.74 I 15.16 22.50 17.71 23.29 117. 53 24. 37 I 19. 48 

(feet) 

4. 84 4.92 

16.58 

4. 79 15.76 

14.89 

1 Calculations based on U.S. Coast and Geodetic 

Survey adjustment factor used on other Homer 

Spit bench marks. 

ments, has been determined at 

tidal bench marks (table 1) by the 

U.S. Coast and Geodetic Survey 

(1964b) and the Alaska Highway 

Depart1nent resurvey. The area 

of greatest subsidence, about 10 

feet, is in the vicinity of the spoil 

pile formed by exca va6on of the 

small-boat harbor. Undoubtedly 

this material beea.me eom pacted 

much more than the natural spit 

material. However, this area is 

adjacent to the breakwater slide, 

and the subsidenee may be related 

to differential compaction or lateral spreading behind the submarine landslide. Release of pore 

pressure in a compacting silt accompanied the slide, and "progressive liquefaction" eould have 

,.,...,-- ~--~----/ \ - \ '\ \1 \ /'-,.., 

\ I 

\ I 

v 

12.-Profiles of Homer Spit surveys by the Alaska Highway Department. Datum is U.S. Bureau of Public Roads temporary 

bench mark 20, 70.25 feet above (preearthquake) datum. Vertical exaggeration X 200. 
D14 

extended landward (Terzaghi, 

1956). 

The conditions indicating differential compaction near the end 

of the spit may also be related to 

a submarine landslide. Apparently liquefaction of a water-bearing silt in the material underlying 

the end of the spit could provide 

an explanation for the compaction 

or lateral spreading. The log of 

well 120 (table 2) shows silty layers at 96-104, 110'-1'23, 130'---138, 

and 140-165 feet which can be correlated with the depths of the 

anomalous features on the profiles 

(fig. 11). The earthquake shocks 

probably liquefied the silt; the 

liquefaction in turn caused the 

slope failure and subsidence beyond the scarps. Fortunately, the 

offshore slopes are not very steep; 

otherwise an e.ven greater subsidence of the land near shore might 

have occurred. 

An area of the spit about halfway from the mainland (fig. 12) 

apparently subsided more than adj aeent areas. A possible reason for 

this local difference is suggested by 

the presence of the adjacent barge 

harbor. The harbor was recently 

excavated to a shallow depth to 

permit barge unloading. The excavation may have provided for 

the release of water pressure in a 

metastable formation during the 

earthquake that caused compaetion by progressive liquefaction of 

son1e of the silty sediments. 

Stanley reported postearthquake 

subsidence in an area south of the 

groin-protected shore (p. D25). 

Even the lo·wer high tides flood this 

area nmv. Possible causes of postquake subsidenee are: ( 1) the additional diurnal loading of the material in the spit by the high tides, 

and (2) the gradual release of pore 

pressure that may have been built 

up in fine-grained material during 

the earthquake, and a resultant 

compression of the material. 

ALASKA EARTHQUAKE, MARCH 27, 1964 

TABLE 2.-Log of well120. Kachemak Water Co. 

[Drilled and logged by A. H. Thorn) 

Material 

Deposits of Quaternary age: 

Gravel and sand ___________________________________________ _ 

Gravel and sand (salt water from here on) ____________________ _ 

Sand, coal float, and graveL ________________________________ _ 

Gravel, large, and sand _____________________________________ _ 

Gravel, small and medium, and san'd _________________________ _ 

Gravel, large and medium, and sand _________________________ _ 

Silt, sand, gravel, and sea shells _____________________________ _ 

Sand, coarse, and some graveL ______________________________ _ 

Silt, sand, small gravel, and coal float ________________________ _ 

Gravel, large, and sand _____________________________________ _ 

Gravel and sand; some clay ___________________ - - ____________ _ 

Sand, coarse, and some graveL ______________________________ _ 

Sand, fine, and silt ________ - ____ -----------------------------

Gravel and sand __________ - _____ -- ------- --- -- -- --- ---- -- -- -

Silt, fine sand, and coal float_ _______________________________ _ 

Gravel, large, and sand _______ --- __ --- __ -_-----------_----- __ 

Sand, medium ________________________________ - ____________ _ 

Gravel, large, and sand _______________________ -- ___ - ________ _ 

Silt, sand, coal float, and some graveL _______________________ _ 

Silt, sand, coal float, and clay "glacial" (hit hard at about 200ft)_ 

Sand, fine, and some gravel; solid ____________________________ _ 

Sandstone, fine __________________ - _ -- --- -- -- -- ----- - - -- -- ---

Silt and sand, fine, blue ____________________________________ _ 

Sand, fine; hard packed-------------------------------------

Sand and some clay; drilled 5 ft ahead _______________________ _ Sandstone ________________________________________________ _ 

Sand, loose, medium; shells _________________________________ _ 

Silt, sand, and clay chunks _________________________________ _ 

Sand, clay, and coal float _____________________ -------------

Sand and blue clay; increasing clay to 289 (water shut off at 273ft)_ 

Silt, sand, coal, and soft clay ________________________________ _ 

Sand, fine (salt water ends) _________________________________ _ 

Sand and clay ________ - - -- -- -- --- - --- --- - --- --- - --- - --- - - -- -

Clay, blue, sand and gravel; unit gradually increasing in clay 

content _________________________________________________ _ 

Clay, blue ________________________________________________ _ 

Clay, blue; some gravel and gas (flammable) __________________ _ 

Clay, blue, and sand ___________ - ___________ -----------------

Clay, blue, and semiliquid paste sand (salty water rises to 150 ft) _ 

Clay, soft (drilled ahead, still water) _________________________ _ 

Gravel and clay (no water) _________________________________ _ 

Clay, "marine" (water slow) ________________________________ _ 

Clay, soft "marine"; gradually getting harder (no water) _______ _ Clay, blue, hard ___________________________________________ _ 

Clay, soft, semiliquid ______________________________________ _ 

Sandstone, fine; contains small shells and coal bits _____________ _ Clay, soft _________________________________________________ _ 

Clay, hard ________________________________________________ _ 

Kenai Formation(?) ___________________________ -- ____ - ___ -- __ 

N OTE.-The Kenai Formation may have been encountered at 289 ft.. 

of gas below 327ft suggests the presence of the Kenai Formation. 

Thickness Depth (feet) (feet) 

16 16 

40 56 

6 62 

5 67 

25 92 

4 96 

8 104 

6 110 

13 123 

2 125 

3 128 

2 130 

8 138 

2 140 

25 165 

6 171 

3 174 

8 182 

15 197 

13 210 

3 213 

1 214 

6 220 

2 222 

21 243 

4 247 

5 252 

5 257 

6 263 

26 289 

4 293 

1 294 

3 297 

24 321 

6 327 

15 342 

1 343 

6 349 

2 351 

15 366 

18 384 

33 417 

8 425 

4 429 

2 431 

31 462 

6 468 

9 477 

The presence 

HYDROLOGIC EFFECTS 

Earthquake shock waves affect 

water bodies at great distances 

from the epicenters. Surfacewater bodies act like inverted pendulums and are set in motion as 

the land moves under them. Oscillating waves, ealled seiehes, are 

formed and can, under some circumstances, develop into large 

\vaves that may be destructive. 

Seiehes presumably were de:vel-
oped in Kachemak Bay, Beluga 

Lake, other smaller lakes, in free 

pools of water in the creeks, and 

in water tanks in the Homer area. 

Most of the lakes and streams were 

ice covered on March 27. Seiches 

develop in water standing in wells 

also, but generally they are not 

noticeable in artesian wells because 

the seismic waves are compressing 

and dilating the confined aquifers 

and are thus causing a much 

greater effect on the water in the 

casing. These surges in artesian 

wells are usually not noted unless 

water is forced out of the well or 

the motion is recorded instrumentaUy. 

At Homer, most of the observed 

hydrologic effects of the March 

1964 earthquake were neglible. 

Many possible effects cannot be 

ascertained because few hydrologic data had been collected in the 

area before the quake. 

IMMEDIATE EFFECTS 

The most noticeable effect of 

the earthquake on the hydrology 

of Homer was the breaking of ice 

and seiching of water in Beluga 

Lake. Presumably the other small 

lakes and ponds in the area reacted 

similarly. At Beluga Lake, nearshore ice was broken by compression and overriding, and the rest 

of the ice was broken in random 

patterns. The north and south 

shores apparently had the most 

overridden ice. The ice was not 

broken as much along the west 

shore, which is formed by the 

highway (fig. 2). However, this 

western section of the lake is probably the deepest part or has the 

steepest nearshore lake-bottom 

gradient; either characteristic 

would tend to reduce the overriding effect. Natural and artifidal 

lakes in other areas appeared to 

show preferred directions of ice 

breakage related to the direction 

EFFECTS IN THE HOMER AREA 

of the earthquake-·wave propagation (Grantz and others, 1964, 

p. 6). 

Streams were near their lowest 

annual flow and had their thickest cover of ice at the time of the 

earthquake. All streams in this 

area are small and have narrow 

flood plains. Hence, very few effects on strean1s were noted by 

residents. 

Increased or decreased stream 

discharge could not be determined 

because of lack of appropriate records. The only evidence that 

might indicate a greater discharge 

is the level of Beluga Lake. Four 

measurements made at the lake 

outlet in the May-August 1964 period showed that the lake level was 

averaging 2-3 feet higher than 

comparable periods in 196·2 and 

1963. This higher level may have 

been due to increased discharge of 

the escarpment streams feeding the 

lake. 

A temporary increase in sediInent load probably resulted from 

landslides and rockfalls in the canyons along the escarpment; in l\fay 

extremely silt-laden flows of the 

streams occurred. Precipitation 

in April and May was about average. Analogy with daily observations on a stream near Palmer 

(Waller, 1966) indicates that the 

increased sediment load probably 

lasted about a month. As soon as 

aU the finer material of the slide 

debris was washed away, the 

streams resumed their normal erosive pattern. The sediment load 

presumably was carried to the 

lower reaches of the streams. 

Bear Creek and five lesser streams 

deposit their sediment loads in 

Beluga Lake. 

The immediate effects on the 

ground water included a few failures of domestic water-well systems and muddied or turbid well 

or spring water. There were no 

water-level recorders on wells in 

D15 

the Homer area, but the observed 

movement of the land, the eff.ects 

noted above, and observations .elsewhere (Plafker, 1965; Waller 

and others, 1965) indicate with 

certainty that ground water in the 

Homer area was affected by the 

earth tremors. These effects are 

shown by residual changes of 

water levels in wells which ha.d 

records of water-level measurements extending back to 1962 

(fig. 13, next page). 

The failures of some of the 

well systems resulted from sanding or silting of the pump due to 

agitation of the wells and differential movement of well casings 

and the surrounding rock. l\fost 

of the wells are unscreened and 

have 1 to several feet of uncased 

hole (Waller, 1963, table 1). 

These conditions readily lend 

themselves to caving or slumping 

of the -..valls under earthquake 

stress. Hence, pumps turned on 

or automatically activated when 

electric power was restored 

pumped this material into the 

system and caused turbid water 

or malfunction of the pump. 

Other wells that have pumps requiring a full pipe of water for 

a prime probably lost their prime 

owing to surging in the well. 

Thus, reports of dry wells were 

common, as they usually are after 

most earthquakes. 

Water quality is and has been 

a serious problem at Homer. The 

various aquifers differ from one 

another in chemical quality of 

the water. Gas is present in the 

water at many places. Temporary changes in water quality at 

Homer are probably related to 

turbidity, whereas any permanent 

changes that might be noticed 

later may be due to leakage between aquifers along loosened 

well casings. The stresses may 

also have caused local increases 

In fractures or permeability 
D16 

Well60 

10 Depth 75 f~----

15 

20 

ALASKA EARTHQUAKE, MARCH 27, 1964 

-------? 

---?........._ ............ ........ _ 

---~------

--

r----- I ------- 1 

_J 

--- 1--

Lilw 

I.J..<( 

LiJ 

~~ 

u 

30L_ 

25 

________________________ _l ______________________________ 

---1 ~L_ 

-______________________________ ~-------

-::J 

ffiCil 

~~ ~<( 

o...J 

I-~ 

Io 

tll1 

wC:O 

0 

z 

0(1) 

-w 

I-I 

~u 

a:~ 

8~ a:: 

a... 

1;6 ~-:-p-~~-~ ;-=~=f:::t ==::::--------=-------~1----_-_-_-_ -----------,------------------1j~--------------------===:::::::=-------lr-_-/-~j 

1: ~ Welll5 I ~ 15 b?epth 123ft ~ 

10 

15 

20 

25 

5 

4 

3 

2 

1 

0 

~- -\ t---- r--- ---------------- r- -- --, 

/ ............................. 

-

~ We1149 \ 

~//' / r--, - Depth 24ft 

r- ~-

13.-Hydrographs of five Homer wells showing long-term effects of the earthquake. Locations of wells s.hown on figure 2. 

which would allow interchange 

of aquifer waters. 

Many wells were reported to 

have become dry because of the 

earthquake, but only two of these 

reports were verified. One well 

(No. 99, fig. 2) was checked by 

the local driller who reported 

(A. H. Thorn, oral commun., 

July 11, 1964) that the well was 

"bone dry" and when he poured 

two pails of water in the well 

"they drained right out." Mr. 

Thorn also reported that other 

wells had sanded up and that one 

near Bluff Point lost most of its 

yield. This location is near the 

bluff, and the water level probably feU because of increased discharge from the aquifer through 

a fracture in the bluff. All the 

affected wells obtain water from 

sand in the Kenai Formation. 

The gradual loss of water in the 

other well verified dry is discussed 

onpageD17. 

LONG-TERM EFFECTS 

Long-term hydrologic effects of 

earthquakes include increased or 

decreased stream discharge, increased sediment loads of streams, 

aggradation or buildup of stream 

ehannels resulting frmn lowered 

land surfaces, ehanges in water 

quality, and residual ehanges in 

water levels in wells. The only 

quantitative data available at 

Hmner relate to water-level 

changes in wells. An observationwell network was maintained from 

March 1962 until August 1963 to 

aid in studying the ground-water 

hydrology of the area. Data on 

stream flow consisted of only a few 

random discharge measurements, 

and data on sediment load of 

streams were nonexistent. Data on 

the quality of ground water, on 

the other hand, were available for 

many places (Waller, 1963, table 

3), but no long-term changes in 

water quality appear to have occurred except in a shallow aquifer 

on Homer Spit. 

GROUND WATER 

Long-term changes in water 

levels in wells at Homer were indicwted by residual changes from 

prequake levels. These residuals, 

whether permanent or semipermanent, indicate changes in the 

physical structure of the aquifers. 

Such residual changes in artesian 

pressure as a result of othe,r earthquakes have been reported (Piper, 

1933; Leggette and Taylor, 1935; 

Piper and others, 1939; Thomas, 

1940 ; LaRocque, 1941 ; Brown and 

Ayer, 1948; Tsuya, 1950; Davis 

and others, 1955; Ferris and 

others, 1955 ; Swenson, 1964.) 

Many of the authors cited also discussed the mechanisms involved in 

causing the changes. In brief, 

residual changes are caused by a 

change 1n aquifer-pore space 

created by rearrangement of 
grains or fractures as a result of 

the release or development of stress 

or strain imposed by an earthquake. 

Of the 19 Homer wells for which 

previous periodic water-level observations were made, 15 were remeasured during 1964. The first 

two rounds of postearthquake 

measurements showed three wells 

in which water levels were unchanged, four in which water 

levels were higher, and eight in 

which water levels were lower than 

before the quake. These residual 

changes, some of which may be 

permanent, show no apparent correlation with location on the upland, bench, or lowland, nor with 

Tertiary versus Quaternary aquifers. Bee a use the first measurements were not made until 

9 days after the earthquake, the 

extremes of change are not known. 

The hydrographs of the five 

wells previously used for observation that showed the largest residual changes in water levels are 

plotted in figure 13. The hydrograph for the 8-month period before March 27, when no water 

levels were determined, is estimated on the basis of the earlier 

records and depends on the writer's knowledge of hydrologic conditions at Homer and on correlative seasonal control by measurements in wells in the Matanuska 

Valley and Anchorage. 

The record for well 49, dug on 

the escarpment near Bluff Point 

(fig. 2), is of special interest. The 

well is 24 feet deep and is unused; 

it taps an unconfined aquifer. The 

water level in the well dropped 

steadily for about 3 months after 

the earthquake. The June measurement found only moist mud at 

the bottom of the well; thus the 

water level dropped at least 9 feet 

and possibly as n1ueh as 14 feet. 

In July the water level made a 

recovery, and a complete reeovery 

EFFECTS IN THE HOMER AREA 

was finally shown, nearly 8 months 

after the quake, by the November 

measure1nent. However, the 1965 

winter measurements showed a 

decline that did not occur in preceding winter periods, but one that 

is comparable to the postearthquake decline. 

Well 49 probably taps a local 

water body perched on virtually 

impermeable Tertiary roek. This 

impermeable layer fractured, 

probably minutely from surface 

fissures, and allowed the perched 

water to drain slowly do,vnward 

or laterally toward a nearby topographic low. Recharge from 

summer and fall precipitaton exceeded the percolation rate and 

allowed the water to accumulate 

to its former level. As winter 

frost developed and inhibited recharge, the water table again 

fell, but to a lower level than 

previously, attesting to an increase 

in permeability of at least a 

nearby part of the Tertiary 

rocks. Surface fissures were not 

noticed in the heavily grass-covered area, but numerous fissures 

were seen nearby (fig. 5). The 

behavior of this well and the local conditions are similar to those 

of a well described by Brown and 

Ayer ( 1948) . 

Well 15 on the lowland bench 

(fig. 2) also shows a change that is 

obviously due to the earthquake. It 

is a 123-foot drilled unused well 

tapping an artesian aquifer in 

sand of Tertiary age (Waller, 

1963). The casing reportedly extends to 123 feet and is open 

ended. The water level in this 

well had not varied more than 

0.6 foot in the 2 years of measurements before the ea,rthquake. 

The water level in this well was 

displaced downward more than 8 

feet when measured on April 5, 

9 days after the earthquake. 

Subsequent measurements show -a 

steady rise, and full recovery to 

D17 

preearthquake levels may be 

achieved in time. 

The hydrogra ph for well 56 

shows an immediate residual rise 

of about 12¥2 feet, perhaps because compaction of the aquifer 

caused decreased permeability 

and a higher static head. The 

persistence of the higher water 

level may be a result of deereased 

use during the summer of 1964. 

The well is normally used to supply water by tank truek to the 

Land's End Hotel during the 

summer tourist season, but the 

hotel's "face lifting" during the 

1964 season cancelled the need for 

a fresh-water supply. Well 60 

also shows a rise that may be due 

to seisn'lic causes, such as a decrease in porosity of the sand 

aquifer. Well 59, as indicated by 

the hydrograph, showed little or 

no effect from the earthquake. 

One well on East Hill R.oad 

near East Road should be mentioned for the record. Measurements, started soon after the well 

was drilled in 1963, showed a 

water level of about 30 feet in this 

121-foot drilled well which taps an 

artesian aquifer in rocks of Tertiary age. Three measurements 

in the period from June 1964 to 

March 1965 show a water level of 

about 61 feet. The well owner 

reported that he had installed an 

automatic clothes washer and 

used it heavily in the interim between the 1963 and 1964 measurements. The lower water level in 

1964 probably reflects the new 

conditions imposed on the well by 

relatively continuous withdrawals 

and not a 30-foot drop resulting 

from the earthquake. 

In summary, some aquifers in 

the Homer area apparently were 

disturbed by the earthquake, but 

most show a gradual return to 

preearthquake conditions, insofar 

as these conditions are reflected by 

water levels in the wells. 
D18 

QUALITY OF WATER 

Changes in quality of water obtained from wells were not noticed by residents of the a.rea, so 

no water samples were taken for 

chemical analysis. 

A change in quality of the 

ALASKA EARTHQUAKE, MARCH 27, 1964 

gTound water on the spit was 

made apparent, however, by the 

death of the evergreen trees at 

the campground (fig. 2). The 

low knoll at the campground is 

probably inundated by extreme 

high tides that contaminate the 

thin lens of fresh water available 

for the trees prior to the earthquake. A thinning of the lens 

because of subsidence is also a 

possibility. A dug well at Munson Point reportedly was also 

salty after the earthquake but the 

water became fresh by late summer. 

SEISMIC HISTORY AND CONCLUSIONS 

Homer residents are quite used 

to earthquake shocks; however, no 

written history is known of the 

earthquakes recorded or felt in the 

area since it was settled about 

1888. Heck and Eppley (1958) 

and Davis and Echols ( 1962) have 

compiled lists of Alaskan earthquakes from which the writer has 

excerpted data on the location, 

date, and time of earthquakes of 

magnitude 5 or greater that had a 

reported effect at Homer or that 

occurred within a radius of about 

100 miles of Homer (table 3). It 

is hoped that this compilation may 

encourage a more complete recording of such events, possibly by local residents from local archives. 

The table shows that the earliest 

known major earthquake near the 

Homer area occurred in 1883 at 

nearby Augustine Island. 

There have been four earthquakes of magnitude 6.75-7.75 

within a radius of 100 miles of 

Homer. Two earthquakes at or 

near Homer had intensities of V 

to VI on the Modified Mercalli 

scale. 

There is evidence of a large 

landslide at Bluff Point which may 

have been set off by a prehistoric 

earthquake. Barnes and Cobb 

( 1959, pl. 2) mapped the low bench 

beneath the bluff as a landslide 

deposit. Karlstrom ( 1964), how· 

ever, mapped the same bench as a 

moraine of Naptowne age, but. 

noted (p. 47) that the moraine is 

covered by landslide debris during 

a "sudden impulse" of deposition. 

In previous fieldwork (U.S. Geological Survey unpub. data) the 

writer noted the material as landslide debris also but followed 

Karlstrom's mapping scheme. 

The discussion above seems warranted to point out the potential 

of the bluffs-particularly the 700-

foot Bluff Point-to slide if a 

major earthquake occurs close to 

Homer in the future (fig. 16). 

Perhaps of greatest importance 

to Homer is the potential of future tsunamis acting upon Homer 

Spit. The 1883 volcanic eruption 

and ( ? ) earthquake ( Dall, 1884) 

created a wave that undoubtedly 

hit and probably overtopped the 

Homer Spit. The reports from 

Port Graham (fig. 1) observers 

stated (Dall, 1884, p. 92-93) that 

an estimated 30-foot wave rolled in 

at 8 :30 a.m. after they had seen 

and heard the volcano on Augustine Island erupt. The wave deluged houses on the lowland and 

washed boats and canoes away, 

even though the tide was "extremely low." Other waves of lesser 

height followed the first one. It 

seems certain that these waves 

were tsunamis and that they struck 

the Homer Spit also. Evidently, 

tsunamis that would hit Homer 

could only be generated from a 

seis1nic disturbance in the lower 

Cook Inlet area because of 

Homer's somewhat sheltered location from the open sea. Seiches, 

however, can develop with any 

major earthquake in the region and 

can be destructive if they coincide 

with high tide. 

Submarine landslides, usually, 

but not always, generated by earthquakes, are another potential 

hazard at the distal end of Homer 

Spit. Thus extensive building on 

the outer end of the spit seems 

very unwise. 
EFFECTS IN THE HOMER AREA 

TABLE 3.-Summary of la1·ge1· earthquakes occurring within about 100 miles of the 

Homer area in the period 1788-1961 

Local Approximate location Estimated 

Date time (lat. N.; long. W.) magnitude Remarks 

(Richter scale) 

Oct. 6, 1883 0800 Augustine Island (59°, ---------- Volcanic activity; 

154°). seismic wave struck Port 

Graham. 

Aug. 1898 South-central Alaska _____ ---------- Trees swayed violently at Susitna 

Station. 

July 11, 1899 Tyonek (61 °, 152°) _______ ---------- Severe. 

Oct. 7, 1900 ------ _____ do_--------------~- ---------- Severe. Probably is same as following one. Oct. 9, 1900 0216 South-cent'ral Alaska _____ ---------- Severe, felt at 

Seldovia. 

Dec. 3Q-31, Kenai __________________ ---------- Volcanic eruption and 

1901. several sea waves. Sept. 19, 1909 1000 Kenai Peninsula _________ ---------- Strong at Seward. 

Sept. 21, 1911 0701 Prince William Sound 6. 9 Severe, felt at 

and Kenai Peninsula Kenai Lake. 

Dec. 9, 1927 

(60.5°, 149°). 

South-central Alaska _____ ---------- Kenai Lake severely 

shaken by three 

Jan. 27, 1931 0429 _____ do _________________ 5-6 

quakes. 

Cracked walls in 

Seward. 

Oct. 6, 1932 0705 IIomer _________________ ---------- Awakened all. 

Apr. 26, 1933 1703 Susitna Flats (61.25°, ---------- At IIomer, worst 

150.5°). shock in 15 years. 

May 13, 1933 Old Tyonek _____________ ---------- Severe, some damage. 

June 13, 1933 0219 Northeast of Nikishki 6. 25 

(61°, 151°). 

June 17, 1934 2314 Soldatna (60.5°, 151°) ____ 6. 75 

Oct. 10, 1940 2153 Mouth of Kachemak Bay 6 

(59.5°, 152°). 

July 29, 1941 1551 Northeast of Nikishki 6. 25 Damage at Anchor-

(61 °1 151 °). age. 

Dec. 5, 1942 0428 Mouth of Kachemak Bay 6. 25 

(59.5°, 152°). 

Sept. 27, 1949 0530 Blying Sound (59.75°, 7 Strong aftershock 

149°). also. Damage at 

Seward and 

June 25, 1951 0612 Chickaloon Bay (61 °, 

Anchorage. 

6. 25 Damage at Anchor150°). age. 

Oct. 3, 1954 0118 Caribou II ills (60°, 151 °) _ 6. 5-7 Damage at IIomer. 

Jan. 24, 1958 1317 North-northwest of 6. 25-6. 5 

Anchor Point (60°, 

152°). 

Mar. 19, 1959 0503 South of Perl Island 6. 25 

June 4, 1959 0231 

(58.6°, 152°). 

50 miles W of Flamer 5. 5 

Dec. 26, 1959 0819 

(59.5°, 153°). 

Stariski Creek (59.9°, 6. 25 

Sept. 5, 1961 0134 

151.7°). 

Bradley Lake (59.8°, 6-6. 25 Felt. Anchorage 

150.6°). rocked. 

Sept. 24, 1961 1627 North of Mount Iliamna 5. 75-6 

(60.3°, 153°). 

D19 
D20 ALASKA EARTHQUAKE, MARCH 27, 1964 

BEACH CHANGES ON HOMER SPIT 

BY KiRK w. STANLEY, ALASKA DEPARTMENT OF NATURAL RESOURCES 

INTRODUCTION 

Homer Spit is a well-known 

landmark on the Kena.i Peninsula 

along the east shore of lower 

Cook Inlet (fig. 14) . Along with 

its growing popularity as a recreational area, the spit provides one 

of the few deep-water ice-free 

ports along the east side of Cook 

Inlet. During the earthquake of 

March 27, 1964, the general area 

subsided tectonically, and the spit 

is now lower by 4.26-5070 feet 

and is nearly 70 percent covered 

during the higher tides (fig. 15). 

The relatively higher stand of the 

sea upon the spit has caused 

changes in shore processes and 

beach morphology which are still 

1n progress. 

GENERAL SETTING 

Homer Spit, about 4 miles long 

and as wide as 1,500 feet, lies 

partially athwart the entrance of 

Kachemak Bay on a shallow shelf 

called Archimandritof Shoals. In 

plan the spit resembles a scimitar, 

with its curved blade pointing 

seaward and its narrow hilt attached to the mainland (fig. 15) . 

The spit is composed largely of 

medi mn gravel, or shingle, intermixed with some sand. Althougl~ 

Homer Spit is considered by 

l{arlstrom ( 1964, p. 20) to be a 

relic glacial feature, the old lateral beach ridges upon the surface clearly illustrate that the 

spit is, at least in its present 

form, a product of littoral processes. The old beach ridges, 

moreover, indicate that the spit 

widened from east to west. During the past few decades, however, the west side of the spit has 

receded slightly eastward near 

the base. 

The source area of material 

composing the Homer Spit is 

probably the mainland to the 

west. The shoreline there is characterized by wave-cut bluffs composed of partially consolidated 

coal-bearing shale and sandstone 

(fig. 16). After the earthquake 

and subsidence, shoreline erosion 

in the source area increased and 

ALASKA 

much new material has entered 

the sea and the littoral drift. 

The net direction of the littoral 

drift along the Cook Inlet side 

of the spit is southeast, whereas 

along the bay side it is probably 

northwest. The maximum calculated wave height along the outside beach is about 10 feet, and 

along the bay ~ide, about 4 feet. 

The tides are of the mixed type; 

two lows and two hi_ghs occur 

200 0 200 400 Ml LES 

r-------------

1 

I 

I 

---------------------~ 

~ 

(y~ 

~ '*' 

~ 

~ 

~ 

~ 

<:j N 

~ 

1 

14.-Index map of Homer Spit. 
EFFECTS IN THE HOMER AREA D21 

Kach emak Bay 

PRE EARTHQUAKE 

-- Longshore drift ---

POSTEARTHQUAKE HIGH-WATER 

C 0 0 K 1000 0 1000 2000 3000 4000 5000 FEET Luullllti __ _L __ L__~--~-~ 

15. Comparison of the high-water line •along Homer Spit before and after the earthquake and submergence of March 27, 1964. 

Light lines on Spit represent old beach llerms. High-water line traced from U.S. Army Corps of Engineers aerial photographs·, 

September 1959, and from U.S. Bureau of Land Management infrared photographs, August 19'64. 

16.-Shoreline west of Homer Spit, probably the source area of material composing 

the spit. 
DZ ALASKA EARTHQUAKE, MARCH 27, 1964 

daily. The maximum tidal range 

is about 23 feet. 

The beach along the spit can be 

conveniently subdivided into an 

upper and a lower foreshore. The 

upper foreshore along both sides of 

the spit slopes from 1 : 00 to 1 : 20, 

but it steepens to about 1 : 8 at the 

seaward, or distal, end. A storm, 

or frontal, berm forms the beach 

crest, but because the berm is higher than the old beach ridges along 

the interior, the spit is sligl~tly 

basin shaped. 

The plunge zone separating the 

upper and lower foreshore is 100- 

300 feet seaward of the beach crest 

and is generally marked along the 

outside beach by a conspicuous 

accumulation of cobbles at about 

the 10-foot level. Seaward of the 

plunge zone the lower foreshore is 

characterized by broad sandbars 

along the outside beach, and by 

wide silty mudflats along the bay 

side. The lower foreshore slopes 

as little as 1: 150, but along both 

sides the slope gradually steepens 

and the width narrows toward the 

distal end of the spit where the 

slope of the lower foreshore steepens to as much as 1 : 10. 

SUBSIDENCE AND POSTEARTHQUAKE CHANGES 

New berm \ 

17.-Beach-face recession diagram showing the preearthquake upper foreshore slope 

(line AD) and the postearthquake slope (line CD). After subsidence, material 

within ABCD, as a result of the higher water level, was scoured and in part carried 

onto the spit where it formed a new frontal berm. 

Tho Homer area, including 

Hoiner Spit, subsided during the 

earthquake, as did other regions 

of south-central Alaska. However, the U.S. Coast and Geodetic 

Survey has not p~~blislled final figures confirming the actual drop. 

The figures released to date are 

based on short-term tide gage 

readings and first-order leveling 

from Anchorage. These data 

show that the total subsidence, including regional subsidence, measured at the end of Homer Spit, 

ranges from 4.26 to 5.70 feet. 

The spit in subsiding apparently 

underwent progressive, but not 

18.-Storm berm developed along spit within 6 months after subsidence. Berm 

before subsidence was less than 3 feet high and 4-5 feet wide at the base. 

unifonn, consolidation and compaction of sediments from the 

land\\-arc1 to the distal end. To 

deteriniile how much the spit 

proper had subsided, the Alaska 

Department of Highways (1064, p. 

8) lnacle a resurvey of the spit soon 

after the earthquake. The control 

usecl for the survey was an existing 

U.S. Coast and Geodetic Survey 

bench mark on the mainland. The 

survey showed the distal end of 

the spit to be 2.5 feet lower, relative to this beach mark, than it was 

prior to tlle earthquake. Early 

evidence iildicated that tlle spit 

subsided progressively from the 

land~~ard to the distal end, however, much of the subsidence due 

to compaction appareiltly occurred 

at the distal end (see p. D13). 

At least one beach slope failure, 

or submarille landslide, and possibly others (p. DlO), occurred at 

the distal end of the spit (fig. 15). 

There is no direct evidence of slope 
EFFECTS IN THE HOMER AREA 

failures elsewhere. Instead, the 

changes and alterations of the 

beach along the Homer Spit are 

related to slow shore processes that 

can be attributed to: (1) the ability of storin waves to act higher 

upon the beach face and (2) the 

increased quantity of material carried to and deposited along the spit 

by the littoral drift. 

BERM DEVELOPMENT AND 

BEACH-FACE RECESSION 

Immediately after subsidence 

the relative higher stand of the 

sea resulted in erosion and the 

consequent recession of the upper 

beach face. A large part of the 

material eroded from the Pace 

was carried onto the spit where 

it formed a new storm or frontal 

berm. The most conspicuous 

berm development is along sections of the outside beach. The 

process of berm development and 

beach-face recession is shown by 

figure 17. The relative higher 

water level has shifted the plunge 

zone shoreward and caused material within area ABCD of figure 

17 to be scoured by wave action. 

Part of the scoured material is 

transported onto the spit by the 

swash and accumulates as a new 

berm. 

As an illustration of berm 

growth, the preearthquake berm 

at the distal end of the spit was 

less than 3 feet high, and 4-5 feet 

wide at the base. Six months 

after the earthquake, the berm, 

as shown by figure 18, Iiacl built 

up to 6 feet in height and had 

widened to nearly 60 feet. Tlie 

same berm after another 6-moilth 

period had widened an additional 

20 feet. Elsewhere the berm has 

migrated around buildings and 

covered and blocked roads. 

The size of the new berm is not 

in proportion to material lost 

from, nor to the recession of, the 

adjacent beach face. Figure 19 

19.-I'hotograyhs taken 6 months after subsidence (top) and a year after subsidence 

(bottom) show that the size of frontal berm is not proportional to the recession of 

the beach face. 

sho~vs an example of this dis- 280), most of the scoured mateparity. Such examples show that rial is carried seaward and is lost. 

a large part of the material To what extent this is true along 

scoured from the beach face was Homer Spit is not known. Howwas not carried onto the spit and ever, the absence of noticeable 

deposited as part of the berm. new shingle along the lower foreAccording to King (1959, p. shore fails to support the conten- 
D24 ALASKA EARTHQUAKE, MARCH 27, 1964 

tion that any appreciable material is migrating toward the sea. 

More likely, the bulk of material 

scoured from any one section of 

the beach has merely drifted farther along the beach. Material 

drifted to the clistal end and not 

deposited on the beach there is 

probably lost to the sea. 

The entire beach face along the 

spit has retreated, but not uniformly so. The most noticeable 

recession is along the outside beach 

where local areas show a loss of 

nearly 30 feet, but 10-15 feet probably approximates the overall 

average. The maximum beachface recession was about 56 feet 

and occurred along one limited 

section at the clistal end of the spit. 

MATERIAL SUPPLY AND 20.-Section removed from seaward end of groin to allow bypasslng or material. 

TRANSPORT 

Subsidence has ushered in what 

can be loosely described as a new 

cycle of shoreline erosion. As a 

result of accelerated erosion in the 

source area, much additional material has entered the littoral drift 

and migrated to the spit. The 

quantity of material now being 

transported by the littoral drift 

can only be estimated, but it 

clearly exceeds the quantity carried before the earthquake. For 

example, observations of groins 

along the spit (fig. 15) indicate 

that about 1 month after subsidence the fill behind the groins began to enlarge noticeably. The 1- 

month lag apparently represents 

the time required for material to 

enter tlie drift and migrate from 

the source area to the spit. 21.-Erosion on the lee side of the last of a series of four grofns, a few days after 

As more material is eroded from the earthquake. 

the source area and migrates to 

the 'pit, it rep1aces and augments more material has become avail- along the outer two-thirds of its 

that lost by "Our able to the spit, less is carried onto length. face. Moreover, the frontal berm the frontal berm and a larger Only a minor quantity of ma- has grown in height and width to 

the extent that after 1 year it is amount remains upon the beach terial migrates from the outside 

overtopped by only the stronger face. As a result, the outside beach beach around the end of the spit to 

storm swashes. Thus, although .is beginning to build, particularly tlie bay side. Moreover, since sub- 
EFFECTS IN THE HOMER AREA 

I 22.-The same area as shown in figure 21, 1 year later, after consltruction of two 

1 new groins (right background). 

23.-Cobble-filled baskets placed 011 beach face to prevent erosion. 

sidence the flooding of the low beach face is obstructed in its 

areas along the bay side at high longshore migration by these nutide separates the beach into rela- merous inlets. The bay-side beach 

therefore is gradually wasting tively short sections. Material (Stanley and Grey, 1963, p. 5), a 

find its around the condition also evident before the 

spit or is scoured from the bay-side earthquake. 

SHORE PROTECTION 

WORKS 

Erosion, always a problem along 

tlie exposed side of the spit near 

its base, was controlled in me area 

prior to the earthquake by four 

timber groins (fig. 15). Shortly 

after the earthquake the fill between the groins was eroded and 

the face receded, but after 1 month 

additional material accumulated 

and the fill exceeded the preearthquake level. Because the groins 

mere adequately protecting the 

slioreline, additionally entrapped 

material served only to deplete the 

amount moving along the beach. 

Therefore, to allow bypassing but 

still preserve the existing fill, a 

50-foot section near the end of tlie 

last two groins was removed (fig. 

20). Some loss of fill occurred, 

but in general the slope of the fill 

adjusted to the new conditions. 

However, erosion on the downdrift 

or lee side of the last groin became 

critical. The eroding area on the 

lee side of the groin is shown by 

figure 21, taken a few days after 

the earthquake. To protect the lee 

side, two additional groins were 

constructed. Figure 22, taken 1 

year after the earthquake, shows 

the extent of accretion in that area. 

Prior to the earthquake, old car 

bodies were placed along one eroding section on the exposed side of 

the spit, and they provided some 

protection. Within a few weeks 

after subsidence, however, the 

larger waves scattered the car 

bodies about the beach. 

At one location a small cannery 

was endangered by undermining. 

Specially manufactured and prefabricated wire baskets were filled 

with cobbles and placed along the 

beach face (fig. 23). After 1 year 

the beach has built up and has 

shown no tendency to scour in 

front of the cobble-filled baskets. 
D26 ALASKA EARTHQUAKE, MARCH 27, 1964 

24.-Bar being built across the entrance of a tidal inlet at distal end of Homer Spit. Photograph by U.S. Army Corps of Engineers, 

April 30, 19M. 
TIDAL INLETS 

Since the earthquake and subsidence, more water enters and 

leaves the tidal inlets on each tidal 

change. During the flood tide, material drifting along the beach is 

deflected in ward toward the basin, 

whereas on the ebb tide the outflow 

tends to deflect the material seaward. As a result, the tidal entrances tend to interrupt longshore 

drifting. 

Some of the finer material migrates into the tidal entrances, and 

considerable sand and silt are being deposited in each basin. The 

coarser material tends to be deposited near the entrances where it 

forms deltalike features. As the 

delta features enlarge, they tend to 

further obstruct material drifting 

along the beach by promoting additional deposition or by deflecting 

the drift sea ward. 

A somewhat different situation 

has developed at the tidal entrance 

on the distal end of the spit (fig. 

24). There the increased rate of 

deposition brought about by the 

added load of material in the littoral drift has caused a bar to 

build outward from the updrift 

Alaska Department of Highways, 1964, 

Homer Spit: Alaska Dept. Highways Reconn. Rept. Proj. F-021-

(14), 16p. 

Barnes, F. F., and Cobb, E. H., 1959, 

Geology and coal resources of the 

Homer district, Kenai coal field, 

Alaska: U.S. Geol. Survey Bull. 

1058-F, p. 217-260. 

Brown, R. H., and Ayre, G. R., 1948, 

Upstate New York in 'Vater levels 

and artesian pressure in observation wells in the United States in 

1945, pt 1, Northeastern States: 

U.S. Geol. Survey ·water-Supply 

Paper 1023, p. 191-195. 

Dall, W. H., 1884, A new volcano island 

EFFECTS IN THE HOMER AREA 

side across the original tidal entrance. As the bar has enlarged, 

the entrance channel has gradually shifted toward the do·wndrift 

side. Deprived of natural increase by the bar, the downdrift 

side of the channel is gradually 

wasting. 

SUMMARY 

Prior to the earthquake, Homer 

Spit had probably attained a stage 

of maturity. Active erosion along 

the land ward third of the spit on 

the Cook Inlet side reflected an 

absence or scarcity of nourishment 

from the source area. Material, 

while accreting along the outer 

two-thirds of the spit, was partially derived from the landward 

third. The growth rate of the 

spit may therefore have been declining through a lack of adequate 

material supply. 

Follmving subsidence the upper 

beach face along the spit was 

eroded and receded. But regional 

subsidence also accelerated erosion 

in the source area-the mainland 

adjacent to the spit. More material thus began to enter the littoral drift and migrate to the spit. 

This added material has tended to 

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89-93. 

Davis, G. H., ·worts, G. F., Jr., and 

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Federal Reconstruction and Development Planning Commission for 

Alaska, 1964, Response to disaster, 

Alaskan earthquake, March 27, 

D27 

offset the loss of material eroded 

from the beach face along the spit 

follo,ving subsidence. 

The increased supply of Inaterial is not likely to decline appreciably for many years, and 

eventually the frontal benn will, if 

not artificially disturbed, achieve 

a height sufficient to prevent overtopping by all but the larger storm 

swashes. As the process of deposition continues, the beach along 

the Cook Inlet side, especially 

along the outer two-thirds of the 

spit, will gradually widen. Along 

the bay side, the beach face will 

probably recede further, and its 

stability will depend, in part, on 

the type and location of artificial 

improvements that may obstruct 

longshore drifting. 

Subsidence has not materially 

altered the nature of shore processes along the spit ; instead it has 

1nerely accelerated their rate. 

Therefore, the lasting effect of 

subsidence upon the spit ( excluding flooding) will be the accentuation of deposition along the 

beach on the Cook Inlet side and 

continued erosion and gradual 

wasting of the beach along the bay 

side of the spit. 

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D28 

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89-90. 

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U.S. GOVERNMENT PRINTING OFFICE: 1966 Q-797-974