Earthquakes: What s Shaking? Yumei Wang, Geohazards Engineer, PE, Oregon Dept of Geology and Mineral Industries (DOGAMI)

Transcription

1 Earthquakes: What s Shaking? Yumei Wang, Geohazards Engineer, PE, Oregon Dept of Geology and Mineral Industries (DOGAMI) June 14, 2016 WRECA Source: Source: Wood vs. Unreinforced Masonry (URM) Shaking Response Differences Shown in Lab

2 Outline

3 Pacific Ring of Fire Source:

4 1980 Mt St Helens Eruption In 1980, volcanoes were a known hazard, but geologists did not understand the earthquake potential of the Cascadia Fault

5 >Magnitude 2 Earthquakes in WA and OR Pacific NW is earthquake county Washington Earthquakes 1949 Olympia M Olympia M Nisqually M6.8 (Tim Walsh, pers comm. 6/6/16) Epicenter colors represents depths Image Source: Created on PNSN webpage Data Source:

6 Eastern WA Historical Seismicity Local faults can produce infrequent but damaging earthquakes, similar to the 1936 Milton Freewater (MF) earthquake MF earthquake was about M6.1 and caused minor damage in both OR and WA Maximum magnitude earthquake in this region about M7.5 Permission from Steve Malone

7 1872 N. Cascades Earthquake ~M6.5-7 Permission from Ivan Wong

8 1872 Landslide Blocked Columbia River Ribbon Cliff (between Entiat and Winesap) Source: Madole et al, 1995

9 Active Faults on Wallula Fault Zone (WFZ) WFZ (several faults) USGS scientists recent WFZ research using lidar, paleoseismology and magnetic surveys Found active faults and evidence of 4 earthquakes in past 30,000 yrs near Finley quarry, WA (star on map) Source: Sherrod B. et al, in press.

10 Cascadia Fault Threat Realized in 1980s Source: Dogami

11 Vertical Slice through Subduction Zone Source:

12 Between Earthquakes Seafloor goes down Coast goes up Source:

13 During an Earthquake Coast goes down Seafloor goes up Source:

14 Tsunami Arrives Minutes After Earthquake

15 AR4 Undersea Landslides: Turbidites Credit: Kathleen Cantner, American Geological Institute

16 Slide 15 AR4 Permission to use? Alison Ryan, 7/7/2015

17 Turbidites Caused by Cascadia Earthquakes (Photo: Chris Goldfinger, 2010) Deep Sea Clay Turbidite Sand

18 Ghost Forest at Copalis River, WA Trees died because the coastal land sank during the 1700 Cascadia earthquake The salt water in the intertidal zone killed them Permission: Brian Atwater; Source:

19 Ghost Forest Source:

20 1700 Tsunami Sand Over Buried Soil & Fire Pits Salmon River, Oregon (Lincoln City, Oregon) Soil from forest (topsoil) occupied by native Americans (fire pit) was struck by a tsunami (tsunami sand) and brought down to intertidal level (tidal mud) by the 1700 Cascadia earthquake Source:

21 When, Where, How Big? (Research by Goldfinger et al, 2012; Source: DOGAMI) Many quakes in 10,000 yr geologic record Last quake: Jan 26, 1700 (316 yrs ago)

22 Where? North-South: Maximum from N. CA to BC East-West: from 50 mi. offshore to under coastline

23 How Big? Could be magnitude 8, or magnitude 9.2 Mw ~9 500 yrs Mw yrs Mw yrs Mw yrs (Source: Goldfinger et al. 2012)

24 Western U.S. Map Probabilistic Expected Earthquake Ground Shaking Olympia Source: US Geological Survey

25 Shaking Duration: Chile vs Northridge Acceleration (g) Chile M8.8 Northridge M Time (seconds) Source: D. Baska, Terracon

26 Cascadia: Double Whammy! Tsunami: arrives ~20 min. Waves & surges for hrs Photo of coastal Japan in 2011 earthquake/tsunami EFFECTS Ground shaking Tsunami (coast) Coast Subsidence Liquefaction Lateral spreading Landslides Ground Settlement Seiches Fires Hazmat spills Infrastructure damage Black out, Fuel shortage (Source: U.S. Navy photo by Mass Communication Specialist 3rd Class Alexander Tidd/Released)

27 Cascadia Fault: Strong Shaking & Extensive Damage in Western OR & WA Extreme Damage by Tsunami Major Damage in Coastal Areas Significant Damage in Valley Light or No Damage in Central and Eastern WA and OR WA OR CA Source: DHS 2011 Analytical Baseline Study

28 IMPACTS: Deaths, Dollars & Downtime Source for upper photo and data: DOGAMI OFR O-07-2 Base Map: Google Earth

29 Deaths, Dollars & Downtime Japan s Damage ~$300 Billion (US) ~6% GDP Oregon Estimates >$30 Billion direct damage (20% OR GDP) Nepal s Damage ~$10 Billion (US) ~50% GDP > 35,000 Buildings Destroyed > 250,000 Buildings Damaged Sources: USGS PAGER direct damage for Japan and Nepal; DOGAMI Special paper 29; DOGAMI IMS 24 (values have been extrapoloated ); 2013 OSSPAC Oregon Resilence Plan and percentage GDP calculations by Yumei Wang

30 Deaths, Dollars & Downtime Photos: Y Wang

31 Examples of Damage Source: YWang Source: ASCE TCLEE members Permission fromles Youd

32 Oregon s Critical Energy Infrastructure Hub Located in Portland Base Map: Google Earth (Info from 2013 DOGAMI Energy Sector Report) Intersection of: Petroleum Natural Gas Electric Liquefaction Risk Fuel from WA refineries. Some crude oil is transported to WA via Oregon.

33 Liquefaction and Lateral Spreading Source: US Geological Survey e.g. Nisqually EQ 2001, Sunset Lake Area Olympia, WA Nisqually Earthquake Clearing House,

34 Liquefaction Hazards Energy Facilities Built on Hydraulic Fill 1905 expo Sources of 3 photos: Oregon Historical Society

35 Fuel Oil Terminals in Portland Many facilities built before seismic design codes & vulnerable Source of 3 photos: Y. Wang June 2011, Yumei Wang, DOGAMI

36 Transportation: Vulnerable Bridges Source of 3 photos: Y. Wang Info: DOGAMI O-13-9

37 1989 CA

38 Electrical Systems Electricity Most electrical networks were not built to withstand earthquakes Electrical systems have significant seismic risk due to ground shaking & ground failure Seismically vulnerable facilities include substations, switch stations, transmission lines, power plants, and key distribution substations Cascadia Earthquake damage will likely result in blackout of the Western Grid BPA seismic vulnerability study & mitigation program Source: 2013 Oregon Resilience Plan (ORP) ENERGY TASK GROUP

39 Transmission Tower Mitigation BPA estimates up to 25 Ft movement towards river. Mitigate in Portland Photos Source: Yumei Wang W. Longview, WA Source: Yumei Wang

40 Towers with Ground Movement Hazard >1m CDRM Source: ASCE TCLEE members Chile s Damage Source: ASCE TCLEE members Source: DOGAMI, Madin

41 Community Interdependencies

42 AR18 Critical Infrastructure Interdependencies To restore electric service, you need to reopen roads To restore water service, you need electricity Source: ASCE TCLEE members To restore fuel supplies you need electricity To reopen roads, you need to restore fuel supplies Source: ASCE TCLEE members Source: ASCE TCLEE members

43 Slide 41 AR18 Photo sources and permission? Alison Ryan, 7/7/2015

44 Interdependencies: Highways & Telco Source: DHS FEMA 2011

45 Resilience Triangle Reduce Losses, Speed Recovery, & Rebuild Better CDRM Source: Yumei Wang

46 BUILDING RESILIENCE Personal and Community Preparedness State of Washington Contacts: Tim Walsh, WA Dept of Natural Resources, Assistant State Geologist Maximilian Dixon, WA Emergency Management, Earthquake Program Manager Personal & Family Earthquake Safety Earthquakes: DROP, COVER & HOLD ON Tsunamis: MOVE INLAND & UPHILL Information for: Family, home, workplace, school

47 7 Steps to Earthquake Resilient Business 1. Identify Potential Hazards 2. Create a Disaster Plan 3. Prepare Disaster Supplies Kit 4. Identify your building s potential weaknesses & begin to fix them 5. Protect yourself & employees during earthquake shaking Drop Cover & Hold On 6. After the earthquake, check for injuries & damage 7. When safe, continue to follow your disaster plan

48 BUILDING RESILIENCE Selected WA State Planning Activities 2000 Magnitude 9 Scientific Consensus Earthquake Hazard Maps WA Geology Portal with 20 earthquake scenarios

49 2012 Resilient Washington State Report Source: eismic-safetycommittee/rws%20final%20re port.pdf BUILDING RESILIENCE

50 BUILDING RESILIENCE Earthquake Resistant Control Buildings Source: DOGAMI O-13-09

51 BUILDING RESILIENCE Earthquake Resistant Emergency Equipment Source: DOGAMI O-13-09

52 BUILDING RESILIENCE Earthquake Resistant Transformers Source: DOGAMI O-13-09

53 BUILDING RESILIENCE Earthquake Resistant Transformers Source: DOGAMI O-13-09

54 BUILDING RESILIENCE

55 BUILDING RESILIENCE

56 BUILDING RESILIENCE

57 Myths & Questions? Will the earthquake not happen? Will my dog warn me? Can I surf the tsunami? Will Seattle be spared? (All answers are NO!) Source: NOAA Source: Public Domain