SHIVA – The Seattle Hazard Identification & Vulnerability Analysis City of Seattle, Office of Emergency Management (206) 233-5076 http://www.seattle.gov/emergency 4/15/2014 Photo Credits: Upper Photo: Grand Trunk Dock Fire, 1914. Image Number 2002.3.2507. Courtesy the Museum of History and Industry. Lower Photo: Perkins Lane, January 1997. Courtesy Tim Walsh. ii Table of Contents Table of Contents ......................................................................................................................................... iii List of Tables ................................................................................................................................................ iv List of Figures ............................................................................................................................................... vi Acknowledgements ....................................................................................................................................... 9 Executive Summary ..................................................................................................................................... 11 Hazard Ranking and Methodology .............................................................................................................. 24 Community Profile ...................................................................................................................................... 29 Emerging Threats ........................................................................................................................................ 67 Geophysical Hazards ................................................................................................................................... 77 Earthquakes ............................................................................................................................................ 79 Landslides .............................................................................................................................................. 103 Volcano Hazards, including Lahars ........................................................................................................ 117 Tsunamis and Seiches ........................................................................................................................... 135 Biological Hazards including Bio-Terrorism .............................................................................................. 153 Intentional Hazards ................................................................................................................................... 159 Social Unrest ......................................................................................................................................... 161 Terrorism ............................................................................................................................................... 171 Active Shooter Incidents ....................................................................................................................... 178 Transportation and Infrastructure ............................................................................................................ 183 Transportation Incidents ....................................................................................................................... 185 Fires ....................................................................................................................................................... 195 HazMat Incidents (Chemical / Radiological Releases and Explosions) ................................................. 205 Infrastructure Failures .......................................................................................................................... 215 Power Outages ...................................................................................................................................... 221 Weather and Climate ................................................................................................................................ 229 Excessive Heat Events (EHE) ................................................................................................................. 231 Flooding................................................................................................................................................. 239 Snow, Ice and Extreme Cold ................................................................................................................. 255 Water Shortages ................................................................................................................................... 263 Windstorms ........................................................................................................................................... 271 Bibliography .............................................................................................................................................. 281 Endnotes ................................................................................................................................................... 292 iii List of Tables Table 1. Hazard Ranking .............................................................................................................................. 25 Table 2. Continued ...................................................................................................................................... 26 Table 3. Relationships Between Primary and Secondary Hazards ............................................................. 28 Table 4. Reference Cities............................................................................................................................. 29 Table 5. Demographic Summary ................................................................................................................ 39 Table 6. Total Employment ........................................................................................................................ 43 Table 7. Land Use, 2004 .............................................................................................................................. 45 Table 8. Age Distribution of Housing Stock. ............................................................................................... 63 Table 9. Modified Mercalli Intensity (MMI) Scale ....................................................................................... 83 Table 10. Earthquake Type and Estimated Frequency ............................................................................... 88 Table 11. Land Use in Liquefaction Prone Areas ......................................................................................... 89 Table 12. Estimated Population, Structures, and Assessed Value in Liquefaction Prone Areas. ............... 90 Table 13. Critical Facilities in Liquefaction Prone Areas. ............................................................................ 91 Table 14. Facilities with Concentrated Vulnerable Populations in Liquefaction Prone Areas .................... 91 Table 15. Zoning in Liquefaction Prone Areas ............................................................................................ 92 Table 16. Growth Centers in Liqufaction Prone Areas. ............................................................................... 93 Table 17. Wildlife Areas in Liquefaction Prone Areas. ................................................................................ 93 Table 18. Land Use in Landslide Prone Area ............................................................................................. 109 Table 19. Estimated Population, Structures and Assessed Value in Area ................................................ 110 Table 20. Critical Facilities within 50ft of Landslide Prone Area. .............................................................. 110 Table 21. Facilities with Concentrated Vulnerable Populations within 50ft of Landslide Prone Area ..... 110 Table 22. Zoning in Landslide Prone Areas. .............................................................................................. 111 Table 23. Growth Centers in Landslide Prone Areas. ............................................................................... 112 Table 24. Wildlife Area in Landslide Prone Areas ..................................................................................... 112 Table 25. Land Use in Post-Lahar Sedimentation Area. ............................................................................ 124 Table 26. Estimated Population, Structures and Assessed Value in Post-Lahar Sedimentation Area ...... 125 Table 27. Critical Facilities in Post-Lahar Sedimentation Area ................................................................. 125 Table 28. Facilities with Concentrated Vulnerable Populations in Post-Lahar Sedimentation Area. ....... 125 Table 29. Zoning in Post-Lahar Sedimentation Area ................................................................................. 126 Table 30. Growth Centers in Post-Lahar Sedimentation Zone ................................................................. 127 Table 31. Wildlife Areas in Post-Lahar Sedimentation Area ..................................................................... 127 Table 32. Land Use in Worst Case Tsunami Inundation Area ................................................................... 140 Table 33.