OCS Report 

MMS 2007-039 

Oil-Spill Risk Analysis: 

Sivulliq Exploration Project

U.S. Department of the Interior 

Minerals Management Service 

Environmental Division 

OCS Report 

MMS 2007-039

Oil-Spill Risk Analysis: 

Sivulliq Exploration Project

 By: Walter R. Johnson 

Charles F. Marshall 

Eileen M. Lear (Editor) 

U.S. Department of the Interior 

Minerals Management Service 

Environmental Division June 2007 

Contents

Page 

Introduction ............................................................................................................................... 1 

Summary of the Proposed Action ............................................................................................. 1 

Location of Sivulliq Exploration Project ......................................................................... 1 

Framework of the Analysis .......................................................................................................1 

Environmental Resource Areas ........................................................................................ 2 

Oil-Spill Trajectory Simulations ...............................................................................................4 

Current and Ice Information From a General Circulation Model .................................... 4 

Wind Information ............................................................................................................. 6 

Conditional Probabilities ............................................................................................................7 

Discussion ..................................................................................................................................7 

Comparisons Through Time ............................................................................................ 7 

References Cited ........................................................................................................................8 

Appendix A: Locations of Environmental Resources Areas ..................................................23 

Appendix B: Conditional Probabilities of Contact to Environmental Resource Areas 

and Land Segments in the Winter Season ................................................................................33 

Appendix C: Conditional Probabilities of Contact to Environmental Resource Areas 

and Land Segments in the Summer Season .............................................................................43 

i
Page 

Figures

1. Locations of Study Area and Sivulliq Hypothetical Spill Site ...................................... 10 

2. Study Area Coastline Divided into Land Segments, Sivulliq Exploration Project ...... 11 

3. Location of Ice Line ...................................................................................................... 12 

4. Nearshore Surface Currents Simulated by the NOAA Model for a Wind from 

 the East at 10 Meters/Second ........................................................................................ 13 

Tables

1-12. Conditional probabilities (expressed as a percent chance) that an oil spill starting at a 

particular location will contact ...... 

 1. a certain environmental resource area within 3 days ........................................ 14 

 2. a certain environmental resource area within 10 days ....................................... 15 

 3. a certain environmental resource area within 30 days ....................................... 16 

 4. a certain environmental resource area within 60 days ....................................... 17 

 5. a certain environmental resource area within 180 days ..................................... 18 

 6. a certain environmental resource area within 360 days ..................................... 19 

 7. a certain land segment within 3 days ................................................................. 20 

 8. a certain land segment within 10 days ............................................................... 20 

 9. a certain land segment within 30 days ............................................................... 20 

 10. a certain land segment within 60 days ............................................................... 20 

 11. a certain land segment within 180 days ............................................................. 21 

 12. a certain land segment within 360 days ............................................................. 21 

ii
Appendix A

Page 

Figures 

A-1. Locations of Spring Leads 1 and 4; Ice/Sea Segments 6, 7, 9, 11, and 13; 

 Narwhal, Jeanette, and Karluk Islands; and Environmental Resource Areas 15, 

 17, and 19.................................................................................................................... 25 

A-2. Locations of Spring Lead 2 and 5; Ice/Sea Segments 8, 10, and 12; and 

 Environmental Resource Areas 14, 16, 18, 20, 21, 24, 39, and 41............................. 26 

A-3. Locations of Spring Lead 3; Simpson Lagoon; Prudhoe Bay; Environmental 

 Resource Areas 25, 28, 31, 34, 36, 38, 40, 42, and 44; Canning River; Simpson 

 Cove; and Arey Lagoon, Hula Hula River.................................................................. 27 

A-4. Locations of Thetis Island; Gwyder Bay; Boulder patch I; Environmental 

 Resource Areas 26, 29, 30, 32, and 37; Flaxman Island; and 

 Whaling Area/Kaktovik .............................................................................................. 28 

A-5. Locations of Spy Island; Bertoncini, Bodfish, and Cottle Islands; Egg and 

 Stump Islands; Environmental Resource Area 27; Pole and Belvedere Islands; 

 and Challenge, Alaska, Duchess, and Northstar Islands ............................................ 29 

A-6. Locations of Leavitt and Pingok Islands; Long Island; Reindeer and Argo 

 Islands; West Dock; Endicott Causeway; Cross and No Name Islands; 

 Tigvariak Island; and Environmental Resource Area 35............................................ 30 

A-7. Locations of Boundary Segments 1-20....................................................................... 31 

Appendix B

Tables

B-1 to B-8. Conditional probabilities (expressed as a percent chance) that an oil spill 

starting at a particular location in the winter season ...... 

B-1. will contact a certain environmental resource area within 3 days ............................... 35 

B-2. will contact a certain environmental resource area within 10 days ............................. 36 

B-3. will contact a certain environmental resource area within 30 days ............................. 37 

B-4. will contact a certain environmental resource area within 60 days ............................. 38 

B-5. will contact a certain environmental resource area within 180 days ........................... 39 

iii
 Page 

Tables 

B-6. will contact a certain environmental resource area within 360 days ........................... 40 

B-7. will contact a certain land segment within 180 day .................................................... 41 

B-8. will contact a certain land segment within 360 days ................................................... 41 

Appendix C

C-1 to C-12. Conditional probabilities (expressed as a percent chance) that an oil spill 

starting at a particular location in the summer season ...... 

C-1. will contact a certain environmental resource area within 3 days ............................... 45 

C-2. will contact a certain environmental resource area within 10 days ............................. 46 

C-3. will contact a certain environmental resource area within 30 days ............................. 47 

C-4. will contact a certain environmental resource area within 60 days ............................. 48 

C-5. will contact a certain environmental resource area within 180 days ........................... 49 

C-6. will contact a certain environmental resource area within 360 days ........................... 50 

C-7. will contact a certain land segment within 3 days ....................................................... 51 

C-8. will contact a certain land segment within 10 days ..................................................... 51 

C-9. will contact a certain land segment within 30 days ..................................................... 51 

C-10. will contact a certain land segment within 60 days ..................................................... 52 

C-11. will contact a certain land segment within 180 days ................................................... 52 

C-12. will contact a certain land segment within 360 days ................................................... 53 

iv
1 

Introduction 

The proposed Shell Offshore, Inc. Beaufort Sea exploration plan (EP) pertains to Outer 

Continental Shelf (OCS) activities in the Beaufort Sea. This report examines the 

probabilities (expressed as percent change) of contact by hypothetical large oil spills from 

Beaufort Sea Leases OCS-Y-1805, 1807, 1808, and 1809—also called the Sivilluq 

exploration project. 

Because oil spills may occur from activities associated with offshore oil exploration, 

production, and transportation, the Minerals Management Service (MMS) formally assesses 

the risk of hypothetical oil spills. When accidental oil spills are evaluated, it is important to 

remember that the occurrence of such spills is fundamentally a matter of probability. The 

probability that an oil spill will contact a specific environmental resource within a given 

time of travel from a certain location or spill point is termed a conditional probability; the 

“condition” being that a spill is assumed to have occurred. Also, the winds, ice, and ocean 

currents that transport oil spills cannot be known for certain. A probabilistic event such as 

oil-spill contact to an environmentally sensitive area cannot be predicted, only an estimate 

of its likelihood (its probability) can be quantified. 

This report summarizes results of the oil-spill risk analysis (OSRA) conducted for the 

Sivulliq Exploration Project. The objective of this analysis was to estimate the relative oilspill contacts associated with oil exploration, production, and transportation from the 

proposed exploration site. A description of the OSRA model used in this analysis can be 

found in previous papers (Smith et al., 1982; LaBelle and Anderson, 1985) and on the 

internet at http://www.mms.gov/eppd/sciences/osmp/index.htm. 

Summary of the Proposed Action 

The central area of the Sivulliq exploration project is located on leases OCS-Y-1807 and 

OCS-Y-1808. The OSRA study area extends from latitude 69o

 N. to 72.5o N. and from 

longitude 138o W. to 157o W. (see figure 1). 

Location of Sivulliq Exploration Project 

The proposed Sivulliq exploration project will use a self-contained offshore drilling facility. 

 Figure 1 shows the location of the Sivulliq project, the site where large oil spills, if they 

were to occur, would originate. The Sivulliq exploration site is centered at 70o

20'48" N. and 

146o

06'17" W. 

Framework of the Analysis 

The OSRA depends not only on the meteorologic, oceanographic, geographic, and sea-ice 

conditions of the study area, but also on the environmental resource areas at risk from oil 

spills. 
2 

Environmental Resource Areas 

The 62 environmental resource areas analyzed were taken from the OSRA for the Liberty 

Development and Production Plan (Johnson et al., 2000). Appendix A (see figures A-1 

through A-6) shows the locations of these areas. These environmental resource areas were 

digitized in the same coordinate system, or base map, used for the trajectory simulations. 

Each environmental resource area that is typically present year-round was treated as being 

vulnerable to oil all year. This method assumes that the environmental resource area is 

sensitive to oil-spill effects throughout the entire year rather than seasonally. Each 

environmental resource area not usually present year-round was treated as vulnerable to 

contact from oil spills only during the months it is likely to be present. The digitized 

environmental resource areas, their months of vulnerability, and the illustrations depicting 

their locations are shown in the list on the following page. 

The locations of 20 boundary segments located along the edges of the study area were also 

digitized in the same coordinate system to quantify spill trajectories that may travel out of 

the study area (see figure A-7). Each boundary segment was treated as being vulnerable all 

year. 

Also included in the analysis was an additional environmental resource area, land, which 

comprised the entire study area coastline. Upon contacting land, the trajectory simulation is 

ended. Land was further analyzed by dividing the Beaufort Sea coastline into 51 land 

segments, 38 of which are in the study area (see figure 2). Land segments 6 through 19 and 

32 through 43 are each approximately 18.64 miles (30 kilometers [km]) long. Land 

segments 20 through 31 are closest to the Sivulliq project and are each approximately 12.43 

miles (20 km) long. 

Because the trajectory model simulates an oil spill as a point, each environmental resource 

area was digitized with an areal extent slightly greater than it actually occupies. For 

example, the digitized shoreline environmental resource areas extend a short distance 

offshore. This extension allows the OSRA model to simulate a spill that approaches and 

partially contacts the environmental resource area (or boundary segment), then withdraws 

and continues along its path. For this analysis, the model calculated trajectory simulations 

over two seasons: winter (October-June) and summer (July-September). 
3 

Environmental Resource Area Months Assumed Vulnerable Figure 

Spring Lead 1 

Spring Lead 2 

Spring Lead 3 

Spring Lead 4 

Spring Lead 5 

Ice/Sea Segment 6 

Ice/Sea Segment 7 

Ice/Sea Segment 8 

Ice/Sea Segment 9 

Ice/Sea Segment 10 

Ice/Sea Segment 11 

Ice/Sea Segment 12 

Ice/Sea Segment 13 

Environmental Resource Area (ERA) 14 

ERA 15 

ERA 16 

ERA 17 

ERA 18 

ERA 19 

ERA 20 

ERA 21 

Simpson Lagoon 

Gwyder Bay 

ERA 24 

Prudhoe Bay 

ERA 26 

ERA 27 

ERA 28 

ERA 29 

ERA 30 

ERA 31 

Water Surface over Boulder Patch I 

Water Surface over Boulder Patch II 

ERA 34 

ERA 35 

ERA 36 

ERA 37 

ERA 38 

ERA 39 

ERA 40 

ERA 41 

Canning River 

ERA 42 

Simpson Cove 

ERA 45 

Arey Lagoon, Hula Hula River 

Whaling Area/Kaktovik 

Thetis Island 

Spy Island 

Leavitt and Pingok Islands 

Bertoncini, Bodfish, and Cottle Islands 

Long Island 

Egg and Stump Islands 

West Dock 

Reindeer and Argo Islands 

Cross and No Name Islands 

Endicott Causeway 

Narwhal, Jeanette, and Karluk Islands 

Tigvariak Island 

Pole and Belvedere Islands 

Challenge, Alaska, Duchess, and Northstar Islands 

Flaxman Island 

April-May 

April-May 

April-May 

April-May 

April-May 

January-December 

January-December 

January-December 

January-December 

January-December 

January-December 

January-December 

January-December 

May-October 

May-October 

May-October 

May-October 

May-October 

May-October 

May-October 

May-October 

May-October 

May-October 

May-October 

May-October 

May-October 

May-October 

May-October 

May-October 

May-October 

January-December 

January-December 

May-October 

May-October 

May-October 

May-October 

May-October 

May-October 

May-October 

May-October 

May-October 

May-October 

May-October 

May-October 

May-October 

May-October 

August-October 

January-December 

January-December 

January-December 

January-December 

January-December 

January-December 

January-December 

January-December 

January-December 

January-December 

January-December 

January-December 

January-December 

January-December 

January-December 

A-1 

A-2 

A-3 

A-1 

A-2 

A-1 

A-1 

A-2 

A-1 

A-2 

A-1 

A-2 

A-1 

A-2 

A-1 

A-2 

A-1 

A-2 

A-1 

A-2 

A-2 

A-3 

A-4 

A-2 

A-3 

A-4 

A-5 

A-3 

A-4 

A-4 

A-3 

A-4 

A-5 

A-3 

A-6 

A-3 

A-4 

A-3 

A-2 

A-3 

A-2 

A-3 

A-2 

A-3 

A-2 

A-3 

A-4 

A-4 

A-5 

A-6 

A-5 

A-6 

A-5 

A-6 

A-6 

A-6 

A-6 

A-1 

A-6 

A-5 

A-5 

A-4 

Source: Johnson et al., 2000
4 

Oil-Spill Trajectory Simulations 

The trajectory simulation portion of the model consists of many hypothetical oil-spill 

trajectories that collectively represent the mean surface transport and the variability of the 

surface transport as a function of time and space. The trajectories represent the Lagrangian 

motion that a particle on the surface might take under given wind, ice, and ocean current 

conditions. Multiple trajectories are simulated to give a statistical representation, over time 

and space, of possible transport under the range of wind, ice, and ocean current conditions 

that exist in the area. 

As the simulated oil spills moved, any contacts with environmental resource areas were 

recorded. Spill movement continued until the spill contacted land, moved out of the study 

area, or aged more than 30 days in open water or 360 days in ice conditions. 

The trajectories simulated by the model represent hypothetical pathways of oil slicks. They 

do not directly consider cleanup, dispersion, or weathering processes that could determine 

the quantity or properties of the oil that might eventually contact environmental resource 

areas or land segments. An implicit analysis of weathering and decay can be considered by 

noting the age of simulated trajectories when they contact environmental resource areas. 

For this analysis, the periods selected were 3, 10, and 30 days (60, 180, and 360 days in ice 

conditions) to represent implicit measures of oil weathering as well as matters relating to 

containment and cleanup. 

Current and Ice Information From a General Circulation Model 

Trajectories are constructed from simulations of wind-driven and density-induced ocean 

flow fields, and the ice motion field. The basic approach is to simulate these time and 

spatially dependent currents separately, then to combine them through linear superposition 

to produce an oil-transport vector. This vector is then used to create a trajectory. 

Simulations are performed for two seasons, winter (October-June) and summer 

(July-September). The choice of this seasonal division was based on meteorological, 

climatological, and biological cycles, as well as consultation with Alaska OCS Region 

environmental analysts. Hedström et al. (1995), and Hedström (1994) detail the modeling 

of each ice motion field and ocean current component. Brief summaries of the methods and 

assumptions follow. 

For cases where the ice concentration is below 80 percent, each trajectory is constructed 

using vector addition of the ocean current field and 3.5 percent of the instantaneous wind 

field—a method based on work done by Huang and Monastero (1982), Smith et al. (1982), 

and Stolzenbach et al. (1977). For cases where the ice concentration is 80 percent or 

greater, the model ice velocity is used to transport the oil. Equations 1 and 2 show the 

components of motion that are simulated and used to describe the oil transport: 
5 

Uoil = Ucurrent + 0.035 Uwind (1) 

 or 

Uoil = Uice (2) 

 where: Uoil = oil drift vector 

 Ucurrent = current vector (when ice concentration < 80%) 

 Uwind = wind speed at 10 m above the sea surface 

 Uice = ice vector (when ice concentration > 80%) 

The wind drift factor was estimated to be 0.035, with a variable drift angle ranging from 0o

to 25o

 clockwise. The drift angle was computed as a function of wind speed according to 

the formula in Samuels et al. (1982). (The drift angle is inversely related to wind speed.) 

For each trajectory simulation, the start time for the first trajectory was the first day of the 

season (winter or summer) of the first year of wind data (1980) at 6 a.m. Greenwich Mean 

Time (GMT). The summer season consists of July 1-September 30, and the winter season is 

October 1-June 30. Each subsequent trajectory was started every 1 day on average, at 

6 a.m. GMT. A total of 6,000 trajectories (3,500 in winter, 2,500 in summer) was launched 

from the Sivulliq exploration site over the 17 years of wind data (1980-1996), and results of 

these trajectory simulations were combined to represent platform risk. 

Offshore: For the Beaufort/Chukchi Sea, the Ucurrent and Uice are simulated using a 

three-dimensional coupled ice-ocean hydrodynamic model (Hedström et al., 1995; 

Hedström, 1994). This model is based on the ocean model of Haidvogel et al. (1991), and 

the ice model of Hibler (1979). The location of each trajectory at each time interval is used 

to select the appropriate ice concentration. Depending on the ice concentration, either the 

ice or water velocity with wind drift from the stored results of the Haidvogel et al. (1991) 

coupled ice-ocean model is used (see eq. 1 and 2 above). Surface transport of the oil slick 

for each spill was simulated as a series of straight-line displacements in 1-hour increments 

of a point governed by the Uoil vectors. 

The trajectories age while they are in the water/on the ice. For each day that the 

hypothetical spill is in the water, the spill ages—up to a total of 30 days. While the spill is 

in the ice (> 80% concentration), the aging process is suspended. The maximum time 

allowed for the transport of oil in the ice is 360 days after which the trajectory is terminated. 

 The 30-day limit is maintained for spill trajectories in open water. 

Summer trajectories are those that start between the beginning of July and the end of 

September. Therefore, any trajectory contacting an environmental resource area, land 

segment, or boundary segment beginning at the end of September is considered a summer 

contact and is counted along with the rest of the contacts from spills launched in the 

summer. 

Nearshore: Inshore of the 20-meter bathymetry contour, Ucurrent is simulated using a twodimensional hydrodynamic model developed by the National Oceanic and Atmospheric 

Administration (NOAA) (Galt, 1980). This model does not have an ice component. In this 
6 

model, an ice mask is applied within the 0-meter and 20-meter water-depth contours to 

simulate the observed shorefast ice zone (see figure 3) from November 1 to June 15. For the 

months of November through June 15, Uice is zero, and the ice concentration is greater than 

or equal to 80 percent. The two-dimensional model incorporated the barrier islands, in 

addition to the coastline. The model of the shallow water is based on the wind forcing and 

the continuity equation. The model was originally developed to simulate wind-driven 

shallow water dynamics in lagoons and shallow coastal areas with a complex shoreline. The 

solutions are determined by a finite element model where the primary balance is between 

the wind forcing friction, the pressure gradients, Coriolis accelerations, and the bottom 

friction. The time dependencies are considered small, and the solution is determined by 

iteration of the velocity and sea-level equations, until the balanced solution is calculated. 

The wind is the primary forcing function, and a sea-level boundary condition of no anomaly 

produced by the particular wind stress is applied far offshore, at the northern boundary of 

the OSRA domain. An example of the currents simulated by this model for a 10-

meter/second wind from the east is shown in figure 4. 

The results of the model were compared to current meter data from the Endicott 

Environmental Monitoring Program to determine if the model was simulating the first order 

transport and the dominant flow. The model simulation was similar to the current meter 

velocities during summer. Example time series from 1985 show the current flow at Endicott 

Station ED1 for the U (east-west) and V (north-south) components, plotted on the same axis 

with the current derived from the NOAA model for U and V (Der-U and Der-V). The series 

show many events that coincide in time, and where the currents derived from the NOAA 

model are generally in good correspondence with the measured currents. Some of the 

events in the measured currents are not particularly well represented, and that is probably 

due to forcing of the current by something other than wind, such as low-frequency 

alongshore wave motions. 

Wind Information 

The 17-year reanalysis of the wind fields used was provided to us by Rutgers. The analysis 

of the wind fields are derived from the National Aeronautics and Space Association/NOAA 

TIROS Operational Vertical Sounder (TOVS) Polar Pathfinder Data Set. These state-ofthe-art data are being readied for distribution to the Arctic modeling community as a 

product of this MMS/Rutgers modeling effort. Available from January 1980 through 

December 1996, the TOVS Polar Pathfinder Data Set provides observations of areas 

poleward of latitude 60o

 N. at a resolution of 100 km x 100 km. Designed to address the 

particular needs of the polar research community, the data set is centered on the North Pole 

and has been gridded using an equal-area azimuthal projection, a version of the Equal-Area 

Scalable Earth-Grid. Variables retrieved from satellite-observed radiances for this product 

include atmospheric temperature, water vapor, skin surface temperature, total effective 

cloud fraction, cloud top pressure and temperature, solar zenith elevation, surface pressure, 

turning angle between geostrophic wind and surface stress over ice, emissivity, boundary 

layer stratification, and geostrophic draft coefficient. The algorithm used to generate these 

grids has been validated through comparisons with surface observations from the North 

Polar drifting meteorological station. 
7 

Conditional Probabilities 

The probability (expressed as percent chance) that a large oil spill will contact a specific 

environmental resource area, land segment, or boundary segment within a given time of 

travel from a certain location or hypothetical spill site is termed a conditional probability, 

the condition being that a large spill is assumed to have occurred. Conditional probabilities 

of contact for 3, 10, and 30 days (60, 180, and 360 days in ice conditions) were calculated 

for the Sivulliq exploration site. These conditional probabilities of contact with 

environmental resource areas and land segments are presented on an annual basis in tables 1 

through 12 and, on a seasonal basis in appendices B (winter) and C (summer). 

Discussion 

Conditional probabilities assume that a large spill has occurred and that the transport of the 

spilled oil depends only on the winds, ice, and ocean currents in the study area. For 

Sivulliq, conditional probabilities of contact (expressed as percent chance) were estimated 

for 3, 10, 30, 60, 180, or 360 days during both winter (see appendix B) and summer (see 

appendix C). However, if the probability of contact to a land segment is less than 0.5 

percent for the entire time interval, the tables are not presented in this report. Winter spills 

are defined as spills that begin in October through June, melt out of the ice, and contact 

during the frozen and open-water period. Summer spills are defined as spills that begin in 

July through September. 

Comparisons Through Time 

The proposed Sivulliq exploration project is close to shore (16-20 km), and it is 

understandable that spills have a probability of contact to the adjacent coastline. 

3 Days: Large spills originating at the Sivulliq hypothetical spill site on an annual basis 

have low probabilities of contact ( 0.5- to 1-percent chance) to land segments within 3 days. 

Land segments 29 and 30 have a 1-percent chance of contact on an annual basis (see 

table 7). The environmental resource areas with the chance of contact greater than 1 percent 

are within a 5-mile radius. Within 3 days, three barrier island groups—Pole and Belvedere 

Islands; Challenge, Alaska, Duchess, and Northstar Islands; and Flaxman Island—have a 1- 

to 2-percent chance of contact from large spills originating from the Sivulliq hypothetical 

spill site (see tables 1 and B-1). Large spills starting during winter from the Sivulliq 

hypothetical spill site have a less than 0.5-percent chance of contacting any land segment 

within 3 days (table not presented). 

The environmental resource areas with the highest probabilities of contact (5- to 22-percent 

chance) within 3 days during the summer are located within a 10-mile radius. The three 

barrier island groups with the highest chances of contact, ranging from 2 to 4 percent, are 

Pole and Belvedere Islands; Challenge, Alaska, Duchess, and Northstar Islands; and 

Flaxman Island (see table C-1). Large spills starting during summer from the Sivulliq 

hypothetical spill site have a chance of contact within 3 days to land segments 27 through 

33 ranging from 1- to 2-percent chance (see table C-7). All other land segments have a less 

than 0.5-percent chance of contact. 
8 

10 Days: The environmental resource areas with the higher probabilities of contact 

(10- to 15-percent chance) from the proposed site, on an annual basis, are within a 25-mile 

radius (see table 2). Large spills starting during winter from the Sivulliq hypothetical spill 

site do not have a chance of contact to any land segments greater than 0.5-percent within 10 

days (table not presented). 

By 10 days, spills starting during summer from the Sivulliq hypothetical spill site have the 

higher chances of contact to environmental resource areas that are within a 15-mile radius, 

ranging from 10 to 32 percent (see table C-2). By 10 days, spills starting during the summer 

from the hypothetical spill site have a chance of contacting additional land segments 22, 25, 

26 and 34 ranging from 1 to 2 percent (see table C-8). The highest chance of contact is to 

land segments 29-34 and range from 2 to 5 percent chance (see table C-8). 

30 Days: By 30 days, large spills starting during winter from the Sivulliq hypothetical spill 

site have the higher probabilities of contact (11- to 13-percent chance) to the environmental 

resource areas that are within a 10-mile radius (see table B-3). The exceptions to this are 

Environmental Resource Area 40 and Ice/Sea Segment 11, which are directly adjacent to the 

Sivulliq hypothetical spill site. Environmental Resource Area 40 has an 11-percent chance 

and Ice/Sea Segment has a 13-percent chance of contact from spills originating at the 

Sivulliq. Spills starting during winter from the Sivulliq hypothetical spill site do not have a 

probability of contact to land segments greater than 0.5 percent within 30 days (table not 

presented). 

By 30 days, the paths of spills starting during summer from the Sivulliq hypothetical spill 

site extend farther from the hypothetical spill site. The higher probabilities of contact to 

environmental resource areas are to those located within a 40-mile radius and range from a 

14- to 46-percent chance (see table C-3). By 30 days, additional land segments 21, 35 and 

39 have a 1-percent chance of contact (see table C-9). The two land segments with the 

highest chance of contact are 30 and 33, at a 6-percent level (see table C-9). 

References Cited 

Galt, J.A., 1980, A finite element solution procedure for the interpolation of current data 

in complex regions: Journal of Physical Oceanography 10(12):1984-1997. 

Haidvogel, D.B., J.L. Wilkin, and R. Young, 1991, A semi-spectral primitive equation 

ocean circulation model using vertical sigma and orthogonal curvilinear horizontal 

coordinates: Journal of Computational Physics 94:151-185. 

Hedström, K.S., 1994, Technical manual for a coupled sea-ice/ocean circulation model 

(version 1), Technical Report, Institute of Marine and Coastal Sciences, Rutgers 

University, prepared for the Minerals Management Service, OCS Study MMS 94-0020, 

117 p. 
9 

Hedström, K.S., D.B. Haidvogel, and S. Signorini, 1995, Model simulations of 

ocean/sea-ice interaction in the western arctic in 1983, final report to the Minerals 

Management Service, OCS Study MMS 95-0001, 78 p. 

Hibler, W.D., III, 1979, A dynamic thermodynamic sea ice model: Journal of Physical 

Oceanography 17:815-849. 

Huang, J.C., and F.C. Monastero, 1982, Review of the state-of-the-art of oil spill 

simulation models: Final report submitted to American Petroleum Institute. 

Johnson, W.R, C.F. Marshall, and E.M. Lear (ed.), 2000, Oil-spill risk analysis: 

liberty development and production plan, U.S. Dept. of the Interior, Minerals 

Management Service, OCS Report MMS 2000-082, 57 p. 

LaBelle, R.P., and C.M. Anderson, 1985, The application of oceanography to 

oil-spill modeling for the Outer Continental Shelf oil and gas leasing program: Marine 

Technology Society 19(2):19-26. 

Samuels, W.B., N.E. Huang, and D.E. Amstutz, 1982, An oil spill trajectory 

analysis model with a variable wind deflection angle: Ocean Engineering 9:347-360. 

Smith, R.A., J.R. Slack, T. Wyant, and K.J. Lanfear, 1982, The oil spill risk 

analysis model of the U.S. Geological Survey: U.S. Geological Survey Professional 

Paper 1227. 

Stolzenbach, K.D., O.S. Madsen, E.E. Adams, A.M. Pollack, and C.K. Cooper, 

1977, A review and evaluation of basic techniques for predicting the behavior of surface 

oil slicks: Ralph M. Parsons Laboratories, Report No. 222. 
Alaska

72o

71o70o69o

Sivulliq Hypothetical Spill Site

10

Figure 1. Locations of Study Area and Sivulliq Hypothetical Spill Site.

156o 155o 154o 153o 152o 151o 150o 149o 148o 147o 146o 145o 144o 

157o
Figure 2. Study Area Coastline Divided into Land Segments, Sivulliq Exploration Pro

72o

71o70o69o

157o 156o 155o 154o 153o 152o 151o 150o 149o 148o 147o 146o 145o 144o 14

157o 156o 155o 154o 153o 152o 151o 150o 149o 148o 147o 146o 145o 144o 14

6 7

8 9 10

11

12 13 14

15

16

17

18 19 20

21

22 23

24

25 26

27

28

29

30

31

32

33 34 

11

Alaska
156o 155o 154o 153o 152o 151o 150o 149o 148o 147o 146o 145o 144o 

157o

72o71o70o

Alaska

157o 156o 155o 154o 153o 152o 151o 150o 149o 148o 147o 146o 145o 144o 

69o

Sivilluq Hypothetical Spill S

Figure 3. Location of Ice Line.

12
Figure 4. Nearshore Surface Currents Simulated by the NOAA Model for a Wind fro

13
Table 1. Conditional probabilities (expressed as percent chance) that an oil spill 

starting at a particular location (Sivulliq) will contact a certain 

environmental resource within 3 days 

Environmental Resource Area Probability 

Land 4 

Spring Lead 1 n 

Spring Lead 2 n 

Spring Lead 3 n 

Spring Lead 4 n 

Spring Lead 5 n 

Ice/Sea Segment 6 n 

Ice/Sea Segment 7 n 

Ice/Sea Segment 8 n 

Ice/Sea Segment 9 n 

Ice/Sea Segment 10 2 

Ice/Sea Segment 11 9 

Ice/Sea Segment 12 n 

Ice/Sea Segment 13 n 

ERA 14 n 

ERA 15 n 

ERA 16 n 

ERA 17 n 

ERA 18 n 

ERA 19 n 

ERA 20 n 

ERA 21 n 

Simpson Lagoon n 

Gwyder Bay n 

ERA 24 n 

Prudhoe Bay n 

ERA 26 n 

ERA 27 n 

ERA 28 n 

ERA 29 n 

ERA 30 1 

ERA 31 n 

Water Surface over Boulder Patch I n 

Water Surface over Boulder Patch II n 

ERA 34 n 

ERA 35 n 

ERA 36 n 

ERA 37 n 

ERA 38 n 

ERA 39 2 

ERA 40 9 

ERA 41 7 

ERA 42 1 

Canning River 4 

Simpson Cove n 

ERA 45 1 

Arey Lagoon, Hula Hula River n 

Whaling Area/Kaktovik n 

Thetis Island n 

Spy Island n 

Leavitt and Pingok Islands n 

Bertoncini, Bodfish, and Cottle Islands n 

Long Island n 

Egg and Stump Islands n 

West Dock n 

Reindeer and Argo Islands n 

Cross and No Name Islands n 

Endicott Causeway n 

Narwhal, Jeanette, and Karluk Islands n 

Tigvariak Island n 

Pole and Belvedere Islands 1 

Challenge, Alaska, Duchess, and Northstar Islands 2 

Flaxman Island 2 

Note: n = Less than 0.5 percent. 

14 
Table 2. Conditional probabilities (expressed as percent chance) that an oil spill 

starting at a particular location (Sivulliq) will contact a certain 

environmental resource within 10 days 

Environmental Resource Area Probability 

Land 11 

Spring Lead 1 n 

Spring Lead 2 n 

Spring Lead 3 n 

Spring Lead 4 n 

Spring Lead 5 n 

Ice/Sea Segment 6 n 

Ice/Sea Segment 7 n 

Ice/Sea Segment 8 n 

Ice/Sea Segment 9 1 

Ice/Sea Segment 10 4 

Ice/Sea Segment 11 15 

Ice/Sea Segment 12 2 

Ice/Sea Segment 13 1 

ERA 14 n 

ERA 15 n 

ERA 16 n 

ERA 17 n 

ERA 18 n 

ERA 19 n 

ERA 20 n 

ERA 21 n 

Simpson Lagoon n 

Gwyder Bay n 

ERA 24 1 

Prudhoe Bay n 

ERA 26 n 

ERA 27 n 

ERA 28 1 

ERA 29 1 

ERA 30 2 

ERA 31 1 

Water Surface over Boulder Patch I 1 

Water Surface over Boulder Patch II 1 

ERA 34 n 

ERA 35 1 

ERA 36 n 

ERA 37 1 

ERA 38 1 

ERA 39 4 

ERA 40 15 

ERA 41 10 

ERA 42 2 

Canning River 6 

Simpson Cove 1 

ERA 45 4 

Arey Lagoon, Hula Hula River 1 

Whaling Area/Kaktovik 2 

Thetis Island n 

Spy Island n 

Leavitt and Pingok Islands n 

Bertoncini, Bodfish, and Cottle Islands n 

Long Island n 

Egg and Stump Islands n 

West Dock n 

Reindeer and Argo Islands 1 

Cross and No Name Islands 1 

Endicott Causeway 1 

Narwhal, Jeanette, and Karluk Islands 1 

Tigvariak Island 1 

Pole and Belvedere Islands 2 

Challenge, Alaska, Duchess, and Northstar Islands 3 

Flaxman Island 3 

Note: n = Less than 0.5 percent. 

15 
Table 3. Conditional probabilities (expressed as percent chance) that an oil spill 

starting at a particular location (Sivulliq) will contact a certain 

environmental resource within 30 days 

Environmental Resource Area Probability 

Land 19 

Spring Lead 1 n 

Spring Lead 2 n 

Spring Lead 3 n 

Spring Lead 4 n 

Spring Lead 5 n 

Ice/Sea Segment 6 n 

Ice/Sea Segment 7 1 

Ice/Sea Segment 8 1 

Ice/Sea Segment 9 3 

Ice/Sea Segment 10 6 

Ice/Sea Segment 11 25 

Ice/Sea Segment 12 4 

Ice/Sea Segment 13 3 

ERA 14 n 

ERA 15 n 

ERA 16 n 

ERA 17 n 

ERA 18 n 

ERA 19 n 

ERA 20 n 

ERA 21 1 

Simpson Lagoon 1 

Gwyder Bay n 

ERA 24 2 

Prudhoe Bay n 

ERA 26 1 

ERA 27 1 

ERA 28 1 

ERA 29 3 

ERA 30 4 

ERA 31 2 

Water Surface over Boulder Patch I 1 

Water Surface over Boulder Patch II 2 

ERA 34 n 

ERA 35 1 

ERA 36 n 

ERA 37 1 

ERA 38 1 

ERA 39 6 

ERA 40 26 

ERA 41 14 

ERA 42 3 

Canning River 9 

Simpson Cove 1 

ERA 45 6 

Arey Lagoon, Hula Hula River 2 

Whaling Area/Kaktovik 4 

 Thetis Island n 

Spy Island n 

Leavitt and Pingok Islands 1 

Bertoncini, Bodfish, and Cottle Islands 1 

Long Island 1 

Egg and Stump Islands 1 

West Dock 1 

Reindeer and Argo Islands 1 

Cross and No Name Islands 2 

Endicott Causeway 1 

Narwhal, Jeanette, and Karluk Islands 2 

Tigvariak Island 1 

Pole and Belvedere Islands 2 

Challenge, Alaska, Duchess, and Northstar Islands 4 

Flaxman Island 4 

Note: n = Less than 0.5 percent. 

16 
Table 4. Conditional probabilities (expressed as percent chance) that an oil spill 

starting at a particular location (Sivulliq) will contact a certain 

environmental resource within 60 days 

Environmental Resource Area Probability 

Land 27 

Spring Lead 1 n 

Spring Lead 2 n 

Spring Lead 3 n 

Spring Lead 4 n 

Spring Lead 5 n 

Ice/Sea Segment 6 1 

Ice/Sea Segment 7 2 

Ice/Sea Segment 8 2 

Ice/Sea Segment 9 4 

Ice/Sea Segment 10 8 

Ice/Sea Segment 11 34 

Ice/Sea Segment 12 4 

Ice/Sea Segment 13 3 

ERA 14 n 

ERA 15 n 

ERA 16 n 

ERA 17 n 

ERA 18 n 

ERA 19 n 

ERA 20 1 

ERA 21 2 

Simpson Lagoon 2 

Gwyder Bay 1 

ERA 24 3 

Prudhoe Bay 1 

ERA 26 2 

ERA 27 1 

ERA 28 2 

ERA 29 5 

ERA 30 5 

ERA 31 3 

Water Surface over Boulder Patch I 2 

Water Surface over Boulder Patch II 2 

ERA 34 n 

ERA 35 1 

ERA 36 1 

ERA 37 1 

ERA 38 2 

ERA 39 9 

ERA 40 38 

ERA 41 18 

ERA 42 5 

Canning River 11 

Simpson Cove 1 

ERA 45 7 

Arey Lagoon, Hula Hula River 3 

Whaling Area/Kaktovik 5 

 Thetis Island n 

Spy Island n 

Leavitt and Pingok Islands 1 

Bertoncini, Bodfish, and Cottle Islands 1 

Long Island 1 

Egg and Stump Islands 1 

West Dock 1 

Reindeer and Argo Islands 2 

Cross and No Name Islands 3 

Endicott Causeway 2 

Narwhal, Jeanette, and Karluk Islands 3 

Tigvariak Island 1 

Pole and Belvedere Islands 2 

Challenge, Alaska, Duchess, and Northstar Islands 5 

Flaxman Island 5 

Note: n = Less than 0.5 percent. 

17 
Table 5. Conditional probabilities (expressed as percent chance) that an oil spill 

starting at a particular location (Sivulliq) will contact a certain 

environmental resource within 180 days 

Environmental Resource Area Probability 

Land 60 

Spring Lead 1 n 

Spring Lead 2 n 

Spring Lead 3 n 

Spring Lead 4 n 

Spring Lead 5 n 

Ice/Sea Segment 6 2 

Ice/Sea Segment 7 3 

Ice/Sea Segment 8 3 

Ice/Sea Segment 9 6 

Ice/Sea Segment 10 14 

Ice/Sea Segment 11 47 

Ice/Sea Segment 12 6 

Ice/Sea Segment 13 3 

ERA 14 n 

ERA 15 n 

ERA 16 n 

ERA 17 1 

ERA 18 n 

ERA 19 1 

ERA 20 2 

ERA 21 5 

Simpson Lagoon 4 

Gwyder Bay 1 

ERA 24 7 

Prudhoe Bay 3 

ERA 26 4 

ERA 27 3 

ERA 28 5 

ERA 29 13 

ERA 30 17 

ERA 31 10 

Water Surface over Boulder Patch I 6 

Water Surface over Boulder Patch II 6 

ERA 34 1 

ERA 35 2 

ERA 36 1 

ERA 37 4 

ERA 38 5 

ERA 39 27 

ERA 40 55 

ERA 41 34 

ERA 42 12 

Canning River 20 

Simpson Cove 3 

ERA 45 13 

Arey Lagoon, Hula Hula River 6 

Whaling Area/Kaktovik 8 

 Thetis Island 1 

Spy Island 1 

Leavitt and Pingok Islands 3 

Bertoncini, Bodfish, and Cottle Islands 2 

Long Island 2 

Egg and Stump Islands 2 

West Dock 2 

Reindeer and Argo Islands 4 

Cross and No Name Islands 8 

Endicott Causeway 4 

Narwhal, Jeanette, and Karluk Islands 9 

Tigvariak Island 2 

Pole and Belvedere Islands 7 

Challenge, Alaska, Duchess, and Northstar Islands 12 

Flaxman Island 12 

 Note: n = Less than 0.5 percent. 

18 
Table 6. Conditional probabilities (expressed as percent chance) that an oil spill 

starting at a particular location (Sivulliq) will contact a certain 

environmental resource within 360 days 

Environmental Resource Area Probability 

Land 90 

Spring Lead 1 n 

Spring Lead 2 n 

Spring Lead 3 n 

Spring Lead 4 n 

Spring Lead 5 n 

Ice/Sea Segment 6 2 

Ice/Sea Segment 7 4 

Ice/Sea Segment 8 4 

Ice/Sea Segment 9 8 

Ice/Sea Segment 10 17 

Ice/Sea Segment 11 51 

Ice/Sea Segment 12 6 

Ice/Sea Segment 13 3 

ERA 14 n 

ERA 15 1 

ERA 16 1 

ERA 17 2 

ERA 18 2 

ERA 19 3 

ERA 20 6 

ERA 21 10 

Simpson Lagoon 10 

Gwyder Bay 2 

ERA 24 14 

Prudhoe Bay 4 

ERA 26 6 

ERA 27 5 

ERA 28 9 

ERA 29 23 

ERA 30 28 

ERA 31 18 

Water Surface over Boulder Patch I 11 

Water Surface over Boulder Patch II 12 

ERA 34 2 

ERA 35 6 

ERA 36 2 

ERA 37 8 

ERA 38 7 

ERA 39 42 

ERA 40 66 

ERA 41 41 

ERA 42 15 

Canning River 24 

Simpson Cove 4 

ERA 45 16 

Arey Lagoon, Hula Hula River 7 

Whaling Area/Kaktovik 10 

 Thetis Island 2 

Spy Island 3 

Leavitt and Pingok Islands 6 

Bertoncini, Bodfish, and Cottle Islands 7 

Long Island 4 

Egg and Stump Islands 4 

West Dock 4 

Reindeer and Argo Islands 8 

Cross and No Name Islands 14 

Endicott Causeway 7 

Narwhal, Jeanette, and Karluk Islands 16 

Tigvariak Island 3 

Pole and Belvedere Islands 13 

Challenge, Alaska, Duchess, and Northstar Islands 18 

Flaxman Island 17 

 Note: n = Less than 0.5 percent. 

19 
Table 7. Conditional probabilities (expressed as percent chance) that an oil spill 

starting at a particular location (Sivulliq) will contact a certain land 

segment within 3 days 

Land Segment Probability 

29 1 

30 1 

Table 8. Conditional probabilities (expressed as percent chance) that an oil spill 

starting at a particular location (Sivulliq) will contact a certain land 

segment within 10 days 

Land Segment Probability 

27 1 

28 1 

29 2 

30 2 

31 1 

32 1 

33 2 

34 1 

Table 9. Conditional probabilities (expressed as percent chance) that an oil spill 

starting at a particular location (Sivulliq) will contact a certain land 

segment within 30 days 

Land Segment Probability 

21 1 

22 1 

23 1 

25 1 

27 1 

28 1 

29 2 

30 3 

31 2 

32 1 

33 3 

34 1 

Table 10. Conditional probabilities (expressed as percent chance) that an oil spill 

starting at a particular location (Sivulliq) will contact a certain land 

segment within 60 days 

Land Segment Probability 

21 1 

22 1 

23 1 

24 1 

25 2 

26 1 

27 2 

28 1 

29 3 

30 3 

31 3 

32 2 

33 4 

34 2 

39 1 

20 
Table 11. Conditional probabilities (expressed as percent chance) that an oil spill 

starting at a particular location (Sivulliq) will contact a certain land 

segment within 180 days 

Land Segment Probability 

17 1 

21 2 

22 2 

23 2 

24 2 

25 4 

26 1 

27 3 

28 2 

29 7 

30 7 

31 7 

32 4 

33 7 

34 4 

39 1 

Table 12. Conditional probabilities (expressed as percent chance) that an oil spill 

starting at a particular location (Sivulliq) will contact a certain land 

segment within 360 days 

Land Segment Probability 

17 1 

18 1 

19 1 

20 2 

21 5 

22 3 

23 3 

24 4 

25 6 

26 2 

27 5 

28 5 

29 9 

30 10 

31 9 

32 5 

33 9 

34 6 

35 1 

39 2 

21 
22 
 Appendix A 

 Locations of Environmental Resource Areas

23
24
72o

71o70o69o

25

157o 156o 155o 154o 153o 152o 151o 150o 149o 148o 147o 146o 145o 144

Figure A-1. Locations of Spring Leads 1 and 4; Ice/Sea Segments 6, 7, 9, 11, and 13; N

Islands; and Environmental Resource Areas 15, 17, and 19.

Alaska

Spring Lead 1

Spring Lead 4

Ice/Sea

Segment 6 Ice/Sea

Segment 7

Ice/Sea

Segment 9

Ice/Sea

Segment 11

S

ERA

15 ERA

19

ERA 17 Narwhal, Jeanette,

and Karluk Islands
72o

71o70o69o

157o 156o 155o 154o 153o 152o 151o 150o 149o 148o 147o 146o 145o 144o 

Spring Lead 2

Spring Lead 5

ERA 14

ERA 16

ERA 18 ERA20

ERA

21

ERA

24

Ice/Sea

Segment 8

ERA

39

ERA

41

ERA

42

ERA

45

Ic

Seg

Alaska

26

Figure A-2. Locations of Spring Leads 2 and 5; Ice/Sea Segments 8, 10, and 12; and E

16, 18, 20, 21, 24, 39, 41, 42, and 45. 

Ice/Sea

Segment 10
Alaska

71o70o69o

157o 156o 155o 154o 153o 152o 151o 150o 149o 148o 147o 146o 145o 144o 

Spring Lead 3

ERA

40

Simpson Lagoon

ERA

28

ERA

31

Prudhoe

Bay

ERA

34

ERA

36

ERA

38

Canning

River

Simpson

Cove

Arey LaHula Hu

72o

27

Figure A-3. Locations of Spring Lead 3; Simpson Lagoon; Prudhoe Bay; Environment

36, 38, and 40; Canning River; Simpson Cove; and Arey Lagoon, Hula Hu
72o

71o70o69o

157o 156o 155o 154o 153o 152o 151o 150o 149o 148o 147o 146o 145o 144o 

Thetis Island

Gwyder Bay

ER26

ERA

29

ERA30

Boulder

Patch I

ERA 37

Flaxman Island

Wha

Alaska

28

Figure A-4. Locations of Thetis Island; Gwyder Bay; Boulder Patch I; Environmental 

Flaxman Island; and Whaling Area/Kaktovik.
72o

71o70o69o

Alaska

157o 156o 155o 154o 153o 152o 151o 150o 149o 148o 147o 146o 145o 144o 

Spy Island

Bertoncini, Bodfish, and

Cottle Islands

Egg and

Stump Islands

29

Figure A-5. Locations of Spy Island; Bertoncini, Bodfish, and Cottle Islands; Egg and 

Resource Area 27; Boulder Patch II; Pole and Belvedere Islands; and ChaNorthstar Islands.

ERA

27

Boulder

Patch II

Pole and Belvedere IslandChallenge, Alaska, Duchess, and Northstar Isl
72o

71o70o69o

157o 156o 155o 154o 153o 152o 151o 150o 149o 148o 147o 146o 145o 144

Alaska

Leavitt and

Pingok Islands

ERA 35

Long Island

30

Figure A-6. Locations of Leavitt and Pingok Islands; Long Island; Reindeer and Argo 

Cross and No Name Islands; Tigvariak Island; and Environmental Resour

Reindeer and

Argo Islands Cross and

No Name Islands

Endicott

Causeway

West

Dock Tigvariak Island
157o 156o 155o 154o 153o 152o 151o 150o 149o 148o 147o 146o 145o 144o 

72o

71o70o69o

1

4

32

5 6 7 8 9 10 

Alaska

Sivulliq Site

Figure A-7. Locations of Boundary Segments 1-20.

31
32
 

Appendix B 

Conditional Probabilities of Contact to 

Environmental Resource Areas and Land Segments 

in the Winter Season 

33 
34 
Table B-1. Conditional probabilities (expressed as percent chance) that an oil 

spill starting at a particular location (Sivulliq) in the winter season will 

contact a certain environmental resource within 3 days 

Environmental Resource Area Probability 

Land n 

Spring Lead 1 n 

Spring Lead 2 n 

Spring Lead 3 n 

Spring Lead 4 n 

Spring Lead 5 n 

Ice/Sea Segment 6 n 

Ice/Sea Segment 7 n 

Ice/Sea Segment 8 n 

Ice/Sea Segment 9 n 

Ice/Sea Segment 10 n 

Ice/Sea Segment 11 1 

Ice/Sea Segment 12 n 

Ice/Sea Segment 13 n 

ERA 14 n 

ERA 15 n 

ERA 16 n 

ERA 17 n 

ERA 18 n 

ERA 19 n 

ERA 20 n 

ERA 21 n 

Simpson Lagoon n 

Gwyder Bay n 

ERA 24 n 

Prudhoe Bay n 

ERA 26 n 

ERA 27 n 

ERA 28 n 

ERA 29 n 

ERA 30 n 

ERA 31 n 

Water Surface over Boulder Patch I n 

Water Surface over Boulder Patch II n 

ERA 34 n 

ERA 35 n 

ERA 36 n 

ERA 37 n 

ERA 38 n 

ERA 39 n 

ERA 40 n 

ERA 41 n 

ERA 42 n 

Canning River n 

Simpson Cove n 

ERA 45 n 

Arey Lagoon, Hula Hula River n 

Whaling Area/Kaktovik n 

Thetis Island n 

Spy Island n 

Leavitt and Pingok Islands n 

Bertoncini, Bodfish, and Cottle Islands n 

Long Island n 

Egg and Stump Islands n 

West Dock n 

Reindeer and Argo Islands n 

Cross and No Name Islands n 

Endicott Causeway n 

Narwhal, Jeanette, and Karluk Islands n 

Tigvariak Island n 

Pole and Belvedere Islands n 

Challenge, Alaska, and Duchess and Northstar Islands n 

Flaxman Island n 

 Note: n = Less than 0.5 percent. 

35 
Table B-2. Conditional probabilities (expressed as percent chance) that an oil spill 

starting at a particular location (Sivulliq) in the winter season will 

contact a certain environmental resource within 10 days 

Environmental Resource Area Probability 

Land n 

Spring Lead 1 n 

Spring Lead 2 n 

Spring Lead 3 n 

Spring Lead 4 n 

Spring Lead 5 n 

Ice/Sea Segment 6 n 

Ice/Sea Segment 7 n 

Ice/Sea Segment 8 n 

Ice/Sea Segment 9 n 

Ice/Sea Segment 10 n 

Ice/Sea Segment 11 5 

Ice/Sea Segment 12 n 

Ice/Sea Segment 13 n 

ERA 14 n 

ERA 15 n 

ERA 16 n 

ERA 17 n 

ERA 18 n 

ERA 19 n 

ERA 20 n 

ERA 21 n 

Simpson Lagoon n 

Gwyder Bay n 

ERA 24 n 

Prudhoe Bay n 

ERA 26 n 

ERA 27 n 

ERA 28 n 

ERA 29 n 

ERA 30 n 

ERA 31 n 

Water Surface over Boulder Patch I n 

Water Surface over Boulder Patch II n 

ERA 34 n 

ERA 35 n 

ERA 36 n 

ERA 37 n 

ERA 38 n 

ERA 39 n 

ERA 40 2 

ERA 41 n 

ERA 42 n 

Canning River n 

Simpson Cove n 

ERA 45 n 

Arey Lagoon, Hula Hula River n 

Whaling Area/Kaktovik n 

Thetis Island n 

Spy Island n 

Leavitt and Pingok Islands n 

Bertoncini, Bodfish, and Cottle Islands n 

Long Island n 

Egg and Stump Islands n 

West Dock n 

Reindeer and Argo Islands n 

Cross and No Name Islands n 

Endicott Causeway n 

Narwhal, Jeanette, and Karluk Islands n 

Tigvariak Island n 

Pole and Belvedere Islands n 

Challenge, Alaska, Duchess, and Northstar Islands n 

Flaxman Island n 

Note: n = Less than 0.5 percent. 

36 
Table B-3. Conditional probabilities (expressed as percent chance) that an oil spill 

starting at a particular location (Sivulliq) in the winter season will 

contact a certain environmental resource within 30 days 

Environmental Resource Area Probability 

Land n 

Spring Lead 1 n 

Spring Lead 2 n 

Spring Lead 3 n 

Spring Lead 4 n 

Spring Lead 5 n 

Ice/Sea Segment 6 n 

Ice/Sea Segment 7 n 

Ice/Sea Segment 8 n 

Ice/Sea Segment 9 n 

Ice/Sea Segment 10 n 

Ice/Sea Segment 11 13 

Ice/Sea Segment 12 n 

Ice/Sea Segment 13 n 

ERA 14 n 

ERA 15 n 

ERA 16 n 

ERA 17 n 

ERA 18 n 

ERA 19 n 

ERA 20 n 

ERA 21 n 

Simpson Lagoon n 

Gwyder Bay n 

ERA 24 n 

Prudhoe Bay n 

ERA 26 n 

ERA 27 n 

ERA 28 n 

ERA 29 n 

ERA 30 n 

ERA 31 n 

Water Surface over Boulder Patch I n 

Water Surface over Boulder Patch II n 

ERA 34 n 

ERA 35 n 

ERA 36 n 

ERA 37 n 

ERA 38 n 

ERA 39 n 

ERA 40 11 

ERA 41 n 

ERA 42 n 

Canning River n 

Simpson Cove n 

ERA 45 n 

Arey Lagoon, Hula Hula River n 

Whaling Area/Kaktovik n 

Thetis Island n 

Spy Island n 

Leavitt and Pingok Islands n 

Bertoncini, Bodfish, and Cottle Islands n 

Long Island n 

Egg and Stump Islands n 

West Dock n 

Reindeer and Argo Islands n 

Cross and No Name Islands n 

Endicott Causeway n 

Narwhal, Jeanette, and Karluk Islands n 

Tigvariak Island n 

Pole and Belvedere Islands n 

Challenge, Alaska, Duchess, and Northstar Islands n 

Flaxman Island n 

Note: n = Less than 0.5 percent. 

37 
Table B-4. Conditional probabilities (expressed as percent chance) that an oil spill 

starting at a particular location (Sivulliq) in the winter season will 

contact a certain environmental resource within 60 days 

Environmental Resource Area Probability 

Land n 

Spring Lead 1 n 

Spring Lead 2 n 

Spring Lead 3 n 

Spring Lead 4 n 

Spring Lead 5 n 

Ice/Sea Segment 6 n 

Ice/Sea Segment 7 n 

Ice/Sea Segment 8 n 

Ice/Sea Segment 9 n 

Ice/Sea Segment 10 1 

Ice/Sea Segment 11 18 

Ice/Sea Segment 12 n 

Ice/Sea Segment 13 n 

ERA 14 n 

ERA 15 n 

ERA 16 n 

ERA 17 n 

ERA 18 n 

ERA 19 n 

ERA 20 n 

ERA 21 n 

Simpson Lagoon n 

Gwyder Bay n 

ERA 24 n 

Prudhoe Bay n 

ERA 26 n 

ERA 27 n 

ERA 28 n 

ERA 29 n 

ERA 30 n 

ERA 31 n 

Water Surface over Boulder Patch I n 

Water Surface over Boulder Patch II n 

ERA 34 n 

ERA 35 n 

ERA 36 n 

ERA 37 n 

ERA 38 n 

ERA 39 n 

ERA 40 27 

ERA 41 n 

ERA 42 n 

Canning River n 

Simpson Cove n 

ERA 45 n 

Arey Lagoon, Hula Hula River n 

Whaling Area/Kaktovik n 

Thetis Island n 

Spy Island n 

Leavitt and Pingok Islands n 

Bertoncini, Bodfish, and Cottle Islands n 

Long Island n 

Egg and Stump Islands n 

West Dock n 

Reindeer and Argo Islands n 

Cross and No Name Islands n 

Endicott Causeway n 

Narwhal, Jeanette, and Karluk Islands n 

Tigvariak Island n 

Pole and Belvedere Islands n 

Challenge, Alaska, Duchess, and Northstar Islands n 

Flaxman Island n 

Note: n = Less than 0.5 percent. 

38 
Table B-5. Conditional probabilities (expressed as percent chance) that an oil spill 

starting at a particular location (Sivulliq) in the winter season will 

contact a certain environmental resource within 180 days 

Environmental Resource Area Probability 

Land 31 

Spring Lead 1 n 

Spring Lead 2 n 

Spring Lead 3 n 

Spring Lead 4 n 

Spring Lead 5 n 

Ice/Sea Segment 6 n 

Ice/Sea Segment 7 1 

Ice/Sea Segment 8 2 

Ice/Sea Segment 9 3 

Ice/Sea Segment 10 10 

Ice/Sea Segment 11 41 

Ice/Sea Segment 12 2 

Ice/Sea Segment 13 n 

ERA 14 n 

ERA 15 n 

ERA 16 n 

ERA 17 1 

ERA 18 n 

ERA 19 1 

ERA 20 2 

ERA 21 5 

Simpson Lagoon 4 

Gwyder Bay 1 

ERA 24 6 

Prudhoe Bay 2 

ERA 26 3 

ERA 27 3 

ERA 28 5 

ERA 29 14 

ERA 30 20 

ERA 31 11 

Water Surface over Boulder Patch I 6 

Water Surface over Boulder Patch II 6 

ERA 34 1 

ERA 35 2 

ERA 36 1 

ERA 37 4 

ERA 38 5 

ERA 39 29 

ERA 40 54 

ERA 41 25 

ERA 42 10 

Canning River 14 

Simpson Cove 3 

ERA 45 8 

Arey Lagoon, Hula Hula River 4 

Whaling Area/Kaktovik 5 

Thetis Island 1 

Spy Island 1 

Leavitt and Pingok Islands 3 

Bertoncini, Bodfish, and Cottle Islands 2 

Long Island 1 

Egg and Stump Islands 2 

West Dock 2 

Reindeer and Argo Islands 4 

Cross and No Name Islands 8 

Endicott Causeway 4 

Narwhal, Jeanette, and Karluk Islands 9 

Tigvariak Island 1 

Pole and Belvedere Islands 7 

Challenge, Alaska, Duchess, and Northstar Islands 11 

Flaxman Island 11 

Note: n = Less than 0.5 percent. 

39 
Table B-6. Conditional probabilities (expressed as percent chance) that an oil spill 

starting at a particular location (Sivulliq) in the winter season will 

contact a certain environmental resource within 360 days 

Environmental Resource Area Probability 

Land 97 

Spring Lead 1 n 

Spring Lead 2 n 

Spring Lead 3 n 

Spring Lead 4 n 

Spring Lead 5 n 

Ice/Sea Segment 6 n 

Ice/Sea Segment 7 3 

Ice/Sea Segment 8 3 

Ice/Sea Segment 9 8 

Ice/Sea Segment 10 16 

Ice/Sea Segment 11 48 

Ice/Sea Segment 12 3 

Ice/Sea Segment 13 1 

ERA 14 n 

ERA 15 1 

ERA 16 1 

ERA 17 3 

ERA 18 2 

ERA 19 4 

ERA 20 8 

ERA 21 13 

Simpson Lagoon 13 

Gwyder Bay 3 

ERA 24 17 

Prudhoe Bay 5 

ERA 26 8 

ERA 27 7 

ERA 28 11 

ERA 29 29 

ERA 30 37 

ERA 31 23 

Water Surface over Boulder Patch I 15 

Water Surface over Boulder Patch II 15 

ERA 34 2 

ERA 35 8 

ERA 36 3 

ERA 37 11 

ERA 38 8 

ERA 39 53 

ERA 40 72 

ERA 41 36 

ERA 42 15 

Canning River 21 

Simpson Cove 4 

ERA 45 13 

Arey Lagoon, Hula Hula Rive 7 

Whaling Area/Kaktovik 9 

Thetis Island 2 

Spy Island 3 

Leavitt and Pingok Islands 8 

Bertoncini, Bodfish, and Cottle Islands 9 

Long Island 5 

Egg and Stump Islands 5 

West Dock 4 

Reindeer and Argo Islands 10 

Cross and No Name Islands 18 

Endicott Causeway 8 

Narwhal, Jeanette, and Karluk Islands 21 

Tigvariak Island 4 

Pole and Belvedere Islands 18 

Challenge, Alaska, Duchess, and Northstar Islands 21 

Flaxman Island 19 

Note: n = Less than 0.5 percent. 

40 
Table B-7. Conditional probabilities (expressed as percent chance) that an oil spill 

starting at a particular location (Sivulliq) in the winter season will 

contact a certain land segment within 180 days 

Land Segment Probability 

17 1 

20 1 

21 2 

22 1 

23 1 

24 2 

25 4 

26 1 

27 3 

28 2 

29 6 

30 6 

31 6 

32 3 

33 6 

34 3 

39 1 

Table B-8. Conditional probabilities (expressed as percent chance) that an oil spill 

starting at a particular location (Sivulliq) in the winter season will 

contact a certain land segment within 360 days 

Land Segment Probability 

17 2 

18 1 

19 2 

20 2 

21 6 

22 4 

23 3 

24 5 

25 6 

26 2 

27 5 

28 6 

29 9 

30 11 

31 8 

32 5 

33 9 

34 6 

39 2 

41 
42 
 

Appendix C 

Conditional Probabilities of Contact to 

Environmental Resource Areas and Land Segments 

in the Summer Season 

43 
44 
Table C-1. Conditional probabilities (expressed as percent chance) that an oil spill 

starting at a particular location (Sivulliq) in the summer season will 

contact a certain environmental resource within 3 days 

Environmental Resource Area Probability 

Land 9 

Spring Lead 1 n 

Spring Lead 2 n 

Spring Lead 3 n 

Spring Lead 4 n 

Spring Lead 5 n 

Ice/Sea Segment 6 n 

Ice/Sea Segment 7 n 

Ice/Sea Segment 8 n 

Ice/Sea Segment 9 1 

Ice/Sea Segment 10 5 

Ice/Sea Segment 11 20 

Ice/Sea Segment 12 n 

Ice/Sea Segment 13 n 

ERA 14 n 

ERA 15 n 

ERA 16 n 

ERA 17 n 

ERA 18 n 

ERA 19 n 

ERA 20 n 

ERA 21 n 

Simpson Lagoon n 

Gwyder Bay n 

ERA 24 n 

Prudhoe Bay n 

ERA 26 n 

ERA 27 n 

ERA 28 n 

ERA 29 n 

ERA 30 1 

ERA 31 1 

Water Surface over Boulder Patch I n 

Water Surface over Boulder Patch II 1 

ERA 34 n 

ERA 35 1 

ERA 36 n 

ERA 37 1 

ERA 38 1 

ERA 39 5 

ERA 40 22 

ERA 41 18 

ERA 42 2 

Canning River 9 

Simpson Cove 1 

ERA 45 3 

Arey Lagoon, Hula Hula River 1 

Whaling Area/Kaktovik 1 

Thetis Island n 

Spy Island n 

Leavitt and Pingok Islands n 

Bertoncini, Bodfish, and Cottle Islands n 

Long Island n 

Egg and Stump Islands n 

West Dock n 

Reindeer and Argo Islands n 

Cross and No Name Islands n 

Endicott Causeway n 

Narwhal, Jeanette, and Karluk Islands 1 

Tigvariak Island 1 

Pole and Belvedere Islands 2 

Challenge, Alaska, Duchess, and Northstar Islands 4 

Flaxman Island 4 

Note: n = Less than 0.5 percent. 

45 
Table C-2. Conditional probabilities (expressed as percent chance) that an oil spill 

starting at a particular location (Sivulliq) in the summer season will 

contact a certain environmental resource within 10 days 

Environmental Resource Area Probability 

Land 26 

Spring Lead 1 n 

Spring Lead 2 n 

Spring Lead 3 n 

Spring Lead 4 n 

Spring Lead 5 n 

Ice/Sea Segment 6 n 

Ice/Sea Segment 7 1 

Ice/Sea Segment 8 1 

Ice/Sea Segment 9 3 

Ice/Sea Segment 10 10 

Ice/Sea Segment 11 29 

Ice/Sea Segment 12 6 

Ice/Sea Segment 13 3 

ERA 14 n 

ERA 15 n 

ERA 16 n 

ERA 17 n 

ERA 18 n 

ERA 19 n 

ERA 20 n 

ERA 21 1 

Simpson Lagoon 1 

Gwyder Bay n 

ERA 24 2 

Prudhoe Bay n 

ERA 26 1 

ERA 27 1 

ERA 28 1 

ERA 29 3 

ERA 30 6 

ERA 31 3 

Water Surface over Boulder Patch I 2 

Water Surface over Boulder Patch II 3 

ERA 34 1 

ERA 35 2 

ERA 36 1 

ERA 37 2 

ERA 38 2 

ERA 39 10 

ERA 40 32 

ERA 41 24 

ERA 42 4 

Canning River 15 

Simpson Cove 2 

ERA 45 9 

Arey Lagoon, Hula Hula River 3 

Whaling Area/Kaktovik 6 

Thetis Island n 

Spy Island n 

Leavitt and Pingok Islands n 

Bertoncini, Bodfish, and Cottle Islands 1 

Long Island 1 

Egg and Stump Islands 1 

West Dock 1 

Reindeer and Argo Islands 1 

Cross and No Name Islands 2 

Endicott Causeway 1 

Narwhal, Jeanette, and Karluk Islands 3 

Tigvariak Island 1 

Pole and Belvedere Islands 4 4 

Challenge, Alaska, Duchess, and Northstar Islands 7 

Flaxman Island 7 

Note: n = Less than 0.5 percent. 

46 
Table C-3. Conditional probabilities (expressed as percent chance) that an oil spill 

starting at a particular location (Sivulliq) in the summer season will 

contact a certain environmental resource within 30 days 

Environmental Resource Area Probability 

Land 47 

Spring Lead 1 n 

Spring Lead 2 n 

Spring Lead 3 n 

Spring Lead 4 n 

Spring Lead 5 n 

Ice/Sea Segment 6 n 

Ice/Sea Segment 7 2 

Ice/Sea Segment 8 3 

Ice/Sea Segment 9 6 

Ice/Sea Segment 10 14 

Ice/Sea Segment 11 43 

Ice/Sea Segment 12 10 

Ice/Sea Segment 13 7 

ERA 14 n 

ERA 15 n 

ERA 16 n 

ERA 17 n 

ERA 18 n 

ERA 19 n 

ERA 20 1 

ERA 21 2 

Simpson Lagoon 2 

Gwyder Bay 1 

ERA 24 5 

Prudhoe Bay 1 

ERA 26 3 

ERA 27 2 

ERA 28 3 

ERA 29 7 

ERA 30 9 

ERA 31 4 

Water Surface over Boulder Patch I 3 

Water Surface over Boulder Patch II 4 

ERA 34 1 

ERA 35 2 

ERA 36 1 

ERA 37 3 

ERA 38 3 

ERA 39 15 

ERA 40 46 

ERA 41 34 

ERA 42 8 

Canning River 21 

Simpson Cove 2 

ERA 45 13 

Arey Lagoon, Hula Hula River 5 

Whaling Area/Kaktovik 9 

Thetis Island n 

Spy Island n 

Leavitt and Pingok Islands 1 

Bertoncini, Bodfish, and Cottle Islands 2 

Long Island 2 

Egg and Stump Islands 2 

West Dock 2 

Reindeer and Argo Islands 3 

Cross and No Name Islands 4 

Endicott Causeway 3 

Narwhal, Jeanette, and Karluk Islands 5 

Tigvariak Island 2 

Pole and Belvedere Islands 5 

Challenge, Alaska, Duchess, and Northstar Islands 9 

Flaxman Island 10 

Note: n = Less than 0.5 percent. 

47 
Table C-4. Conditional probabilities (expressed as percent chance) that an oil spill 

starting at a particular location (Sivulliq) in the summer season will 

contact a certain environmental resource within 60 days 

Environmental Resource Area Probability 

Land 66 

Spring Lead 1 n 

Spring Lead 2 n 

Spring Lead 3 n 

Spring Lead 4 n 

Spring Lead 5 n 

Ice/Sea Segment 6 1 

Ice/Sea Segment 7 4 

Ice/Sea Segment 8 5 

Ice/Sea Segment 9 8 

Ice/Sea Segment 10 18 

Ice/Sea Segment 11 56 

Ice/Sea Segment 12 11 

Ice/Sea Segment 13 7 

ERA 14 n 

ERA 15 n 

ERA 16 n 

ERA 17 1 

ERA 18 n 

ERA 19 n 

ERA 20 2 

ERA 21 4 

Simpson Lagoon 4 

Gwyder Bay 1 

ERA 24 7 

Prudhoe Bay 2 

ERA 26 4 

ERA 27 2 

ERA 28 6 

ERA 29 11 

ERA 30 13 

ERA 31 7 

Water Surface over Boulder Patch I 5 

Water Surface over Boulder Patch II 6 

ERA 34 1 

ERA 35 2 

ERA 36 1 

ERA 37 3 

ERA 38 5 

ERA 39 22 

ERA 40 55 

ERA 41 44 

ERA 42 13 

Canning River 27 

Simpson Cove 3 

ERA 45 17 

Arey Lagoon, Hula Hula River 7 

Whaling Area/Kaktovik 11 

Thetis Island 1 

Spy Island 1 

Leavitt and Pingok Islands 2 

Bertoncini, Bodfish, and Cottle Islands 2 

Long Island 2 

Egg and Stump Islands 3 

West Dock 2 

Reindeer and Argo Islands 4 

Cross and No Name Islands 7 

Endicott Causeway 4 

Narwhal, Jeanette, and Karluk Islands 7 

Tigvariak Island 2 

Pole and Belvedere Islands 6 

Challenge, Alaska, Duchess, and Northstar Islands 13 

Flaxman Island 13 

Note: n = Less than 0.5 percent. 

48 
Table C-5. Conditional probabilities (expressed as percent chance) that an oil spill 

starting at a particular location (Sivulliq) in the summer season will 

contact a certain environmental resource within 180 days 

Environmental Resource Area Probability 

Land 75 

Spring Lead 1 n 

Spring Lead 2 n 

Spring Lead 3 n 

Spring Lead 4 n 

Spring Lead 5 n 

Ice/Sea Segment 6 4 

Ice/Sea Segment 7 6 

Ice/Sea Segment 8 6 

Ice/Sea Segment 9 9 

Ice/Sea Segment 10 19 

Ice/Sea Segment 11 57 

Ice/Sea Segment 12 11 

Ice/Sea Segment 13 7 

ERA 14 n 

ERA 15 n 

ERA 16 n 

ERA 17 1 

ERA 18 n 

ERA 19 n 

ERA 20 2 

ERA 21 5 

Simpson Lagoon 5 

Gwyder Bay 1 

ERA 24 8 

Prudhoe Bay 3 

ERA 26 5 

ERA 27 3 

ERA 28 6 

ERA 29 13 

ERA 30 15 

ERA 31 8 

Water Surface over Boulder Patch I 5 

Water Surface over Boulder Patch II 6 

ERA 34 1 

ERA 35 2 

ERA 36 1 

ERA 37 3 

ERA 38 5 

ERA 39 24 

ERA 40 57 

ERA 41 47 

ERA 42 14 

Canning River 29 

Simpson Cove 3 

ERA 45 19 

Arey Lagoon, Hula Hula River 8 

Whaling Area/Kaktovik 13 

Thetis Island 1 

Spy Island 1 

Leavitt and Pingok Islands 3 

Bertoncini, Bodfish, and Cottle Islands 3 

Long Island 2 

Egg and Stump Islands 3 

West Dock 3 

Reindeer and Argo Islands 5 

Cross and No Name Islands 8 

Endicott Causeway 5 

Narwhal, Jeanette, and Karluk Islands 8 

Tigvariak Island 2 

Pole and Belvedere Islands 6 

Challenge, Alaska, Duchess, and Northstar Islands 14 

Flaxman Island 14 

Note: n = Less than 0.5 percent. 

49 
Table C-6. Conditional probabilities (expressed as percent chance) that an oil spill 

starting at a particular location (Sivulliq) in the summer season will 

contact a certain environmental resource within 360 days 

Environmental Resource Area Probability 

Land 83 

Spring Lead 1 n 

Spring Lead 2 n 

Spring Lead 3 n 

Spring Lead 4 n 

Spring Lead 5 n 

Ice/Sea Segment 6 4 

Ice/Sea Segment 7 6 

Ice/Sea Segment 8 6 

Ice/Sea Segment 9 9 

Ice/Sea Segment 10 20 

Ice/Sea Segment 11 57 

Ice/Sea Segment 12 11 

Ice/Sea Segment 13 7 

ERA 14 1 

ERA 15 1 

ERA 16 1 

ERA 17 2 

ERA 18 2 

ERA 19 2 

ERA 20 3 

ERA 21 7 

Simpson Lagoon 6 

Gwyder Bay 2 

ERA 24 9 

Prudhoe Bay 3 

ERA 26 5 

ERA 27 4 

ERA 28 7 

ERA 29 15 

ERA 30 18 

ERA 31 10 

Water Surface over Boulder Patch I 7 

Water Surface over Boulder Patch II 7 

ERA 34 2 

ERA 35 3 

ERA 36 2 

ERA 37 4 

ERA 38 6 

ERA 39 27 

ERA 40 58 

ERA 41 48 

ERA 42 14 

Canning River 29 

Simpson Cove 3 

ERA 45 19 

Arey Lagoon, Hula Hula River 8 

Whaling Area/Kaktovik 13 

Thetis Island 2 

Spy Island 2 

Leavitt and Pingok Islands 4 

Bertoncini, Bodfish, and Cottle Islands 4 

Long Island 3 

Egg and Stump Islands 4 

West Dock 3 

Reindeer and Argo Islands 6 

Cross and No Name Islands 10 

Endicott Causeway 5 

Narwhal, Jeanette and Karluk 9 

Tigvariak Island 2 

Pole and Belvedere Islands 7 

Challenge, Alaska, Duchess, and Northstar Islands 14 

Flaxman Island 15 

Note: n = Less than 0.5 percent. 

50 
Table C-7. Conditional probabilities (expressed as percent chance) that an oil spill 

starting at a particular location (Sivulliq) in the summer season will 

contact a certain land segment within 3 days 

Land Segment Probability 

27 1 

28 1 

29 2 

30 2 

31 1 

32 1 

33 1 

Table C-8. Conditional probabilities (expressed as percent chance) that an oil spill 

starting at a particular location (Sivulliq) in the summer season will 

contact a certain land segment within 10 days 

Land Segment Probability 

22 1 

25 1 

26 1 

27 2 

28 2 

29 4 

30 5 

31 3 

32 2 

33 4 

34 2 

Table C-9. Conditional probabilities (expressed as percent chance) that an oil spill 

starting at a particular location (Sivulliq) in the summer season will 

contact a certain land segment within 30 days 

Land Segment Probability 

21 1 

22 1 

23 2 

24 1 

25 2 

26 1 

27 3 

28 2 

29 5 

30 6 

31 5 

32 4 

33 6 

34 3 

35 1 

39 1 

51 
Table C-10. Conditional probabilities (expressed as percent chance) that an oil 

spill starting at a particular location (Sivulliq) in the summer season 

will contact a certain land segment within 60 days 

Land Segment Probability 

17 1 

21 2 

22 2 

23 2 

24 2 

25 4 

26 1 

27 4 

28 3 

29 7 

30 8 

31 8 

32 5 

33 9 

34 5 

35 1 

39 1 

Table C-11. Conditional probabilities (expressed as percent chance) that an oil 

spill starting at a particular location (Sivulliq) in the summer season 

will contact a certain environmental resource within 180 days 

Land Segment Probability 

17 1 

21 3 

22 2 

23 2 

24 3 

25 5 

26 2 

27 4 

28 3 

29 8 

30 9 

31 9 

32 5 

33 10 

34 6 

35 1 

39 2 

52 
Table C-12. Conditional probabilities (expressed as percent chance) that an oil 

spill starting at a particular location (Sivulliq) in the summer season 

will contact a certain environmental resource within 360 days 

Land Segment Probability 

17 1 

18 1 

19 1 

20 1 

21 4 

22 2 

23 3 

24 3 

25 5 

26 2 

27 4 

28 3 

29 8 

30 9 

31 9 

32 5 

33 10 

34 6 

35 1 

39 2 

53 
54 
The Department of the Interior Mission

As the Nation's principal conservation agency, the Department of the Interior has responsibility 

for most of our nationally owned public lands and natural resources. This includes fostering 

sound use of our land and water resources; protecting our fish, wildlife, and biological diversity; 

preserving the environmental and cultural values of our national parks and historical places; 

and providing for the enjoyment of life through outdoor recreation. The Department assesses 

our energy and mineral resources and works to ensure that their development is in the best 

interests of all our people by encouraging stewardship and citizen participation in their care. 

The Department also has a major responsibility for American Indian reservation communities 

and for people who live in island territories under U.S. administration. 

The Minerals Management Service Mission 

As a bureau of the Department of the Interior, the Minerals Management Service's (MMS) 

primary responsibilities are to manage the mineral resources located on the Nation's Outer 

Continental Shelf (OCS), collect revenue from the Federal OCS and onshore Federal and Indian 

lands, and distribute those revenues. 

Moreover, in working to meet its responsibilities, the Offshore Minerals Management Program 

administers the OCS competitive leasing program and oversees the safe and environmentally 

sound exploration and production of our Nation's offshore natural gas, oil and other mineral 

resources. The MMS Minerals Revenue Management meets its responsibilities by ensuring the 

efficient, timely and accurate collection and disbursement of revenue from mineral leasing and 

production due to Indian tribes and allottees, States and the U.S. Treasury. 

The MMS strives to fulfill its responsibilities through the general guiding principles of: (1) being 

responsive to the public's concerns and interests by maintaining a dialogue with all potentially 

affected parties and (2) carrying out its programs with an emphasis on working to enhance the 

quality of life for all Americans by lending MMS assistance and expertise to economic 

development and environmental protection.