OCS Report BOEM 2020-003 Oil Spill Risk Analysis: Conditional Probabilities for the Beaufort Sea Planning Area US Department of the Interior Bureau of Ocean Energy Management Headquarters This page intentionally left blank. OCS Report BOEM 2020-003 Oil Spill Risk Analysis: Conditional Probabilities for the Beaufort Sea Planning Area January 2020 Authors: Zhen Li Caryn Smith In-House Document by U.S. Department of the Interior Bureau of Ocean Energy Management Division of Environmental Sciences Sterling, VA US Department of the Interior Bureau of Ocean Energy Management Headquarters This page intentionally left blank. REPORT AVAILABILITY To download a PDF file of this report, go to the U.S. Department of the Interior, Bureau of Ocean Energy Management Oil Spill Risk Analysis web page (https://www.boem.gov/environment/environmental- assessment/oil-spill-risk-analysis-reports). CITATION Li Z, Smith C. 2020. Oil Spill Risk Analysis: Conditional Probabilities for the Beaufort Sea Planning Area. Sterling (VA): U.S. Department of the Interior, Bureau of Ocean Energy Management. OCS Report BOEM 2020-003. 130 p. ABOUT THE COVER This graphic depicts the study area in the Beaufort and Chukchi Seas and boundary segments used in the oil spill risk analysis model for the the Beaufort Sea Planning Area. Table of Contents Table of Contents ........................................................................................................................................... i List of Figures ................................................................................................................................................ ii List of Tables ................................................................................................................................................. iii Abbreviations and Acronyms ....................................................................................................................... vi Introduction ........................................................................................................................................... 1 Framework of the Report ...................................................................................................................... 1 Purpose ........................................................................................................................................ 1 Study Area ................................................................................................................................... 1 OSRA Components ..................................................................................................................... 2 OSRA .................................................................................................................................................... 2 OSRA Model ................................................................................................................................ 2 Model-Simulated Ocean Currents, Sea Ice, and Winds as Inputs to OSRA ...................... 3 Model Domain ..................................................................................................................... 3 Launch Points ..................................................................................................................... 4 Hypothetical Oil Spill Trajectory Simulations ...................................................................... 4 Resources Considered in the Analysis ............................................................................... 5 Conditional Probability Calculation .............................................................................................. 6 OSRA Model Results and Discussion ................................................................................................... 7 Discussion.................................................................................................................................... 7 Conditional Probability Results ........................................................................................... 7 References ............................................................................................................................................ 9 Appendix A: OSRA Figures ......................................................................................................................... 11 Appendix B: Oil Spill Risk Analysis Tables ................................................................................................. 27 B.1 Environmental Resource Area, Land Segment, and Grouped Land Segment Tables ..................... 28 B.2 OSRA Conditional Probability Tables ............................................................................................... 49 B.3 OSRA Table References ................................................................................................................ 115 i List of Figures Figure A-1: Study area, OCS planning area, and BSs used in the OSRA model ............................................... 12 Figure A-2: Hypothetical LAs and PLs used in the OSRA model ........................................................................ 13 Figure A-3a: ERAs used in the OSRA model (Set 1 of 7) ................................................................................... 14 Figure A-3b: ERAs used in the OSRA model (Set 2 of 7) ................................................................................... 15 Figure A-3c: ERAs used in the OSRA model (Set 3 of 7) ................................................................................... 16 Figure A-3d: ERAs used in the OSRA model (Set 4 of 7) ................................................................................... 17 Figure A-3e: ERAs used in the OSRA model (Set 5 of 7) ................................................................................... 18 Figure A-3f: ERAs used in the OSRA model (Set 6 of 7) .................................................................................... 19 Figure A-3g: ERAs used in the OSRA model (Set 7 of 7) ................................................................................... 20 Figure A-4a: LSs used in the OSRA model (Set 1 of 3) ...................................................................................... 21 Figure A-4b: LSs used in the OSRA model (Set 2 of 3) ...................................................................................... 22 Figure A-4c: LSs used in the OSRA model (Set 3 of 3) ...................................................................................... 23 Figure A-5a: GLSs used in the OSRA model (Set 1 of 3) ................................................................................... 24 Figure A-5b: GLSs used in the OSRA model (Set 2 of 3) ................................................................................... 25 Figure A-5c: GLSs used in the OSRA model (Set 3 of 3) ................................................................................... 26 ii List of Tables Table B.1-1. ERAs used in the OSRA model ...................................................................................................... 28 Table B.1-2. ERAs used in the analysis of lower trophic level organisms .......................................................... 31 Table B.1-3. ERAs, LSs, and GLSs used in the analysis of fish ......................................................................... 31 Table B.1-4. ERAs and BSs used in the analysis of marine mammals (whales) ................................................ 35 Table B.1-5. ERAs, LSs, and GLSs used in the analysis of marine mammals (polar bears) .............................. 37 Table B.1-6. ERAs, LSs, and GLSs used in the analysis of marine mammals (walrus) ..................................... 38 Table B.1-7. ERAs, LSs, and GLSs used in the analysis of marine mammals (ice seals) .................................. 39 Table B.1-8. GLSs used in the analysis of terrestrial mammals ......................................................................... 39 Table B.1-9. ERAs and GLSs used in the analysis of birds ................................................................................ 39 Table B.1-10. ERAs, GLSs, and BSs used in the analysis of subsistence resources ........................................ 42 Table B.1-11. LSs used in the OSRA model ....................................................................................................... 44 Table B.1-12 LS ID and the percent type of Environmental Sensitivity Index shoreline closest to the ocean for United States, Alaska shoreline ............................................................................................................. 46 Table B.1-13. GLSs used in the OSRA model .................................................................................................... 48 Table B.2-1. Conditional probability of a large oil spill contacting an ERA in 3 days (annual timeframe) ........... 49 Table B.2-2. Conditional probability of a large oil spill contacting an ERA in 10 days (annual timeframe) ......... 51 Table B.2-3. Conditional probability of a large oil spill contacting an ERA in 30 days (annual timeframe) ......... 52 Table B.2-4. Conditional probability of a large oil spill contacting an ERA in 90 days (annual timeframe) ......... 54 Table B.2-5. Conditional probability of a large oil spill contacting an ERA in 120 days (annual timeframe) ....... 56 Table B.2-6. Conditional probability of