Preparing ODOT Geo-Enviros for Earthquakes and Tsunamis Patrick Corcoran, Associate Professor, OSU Hazards Outreach Specialist, Oregon Sea Grant Extension
Seaside, OR Undated Sendai, Japan Key Message: “We Get What Japan Got”
Preparedness is a State of Mind ► And a verb. An ongoing process of adapting to risk ► If you are preparing for a Cascadia event, you can handle anything ► In the PNW, we need to prepare to the “tsunami standard”
Oregon State University Oregon Sea Grant Extension Building “Community Resilience” 1) Learning about physical coastal processes 2) Assessing their likely impacts on people, environment, infrastructure 3) Developing tools and Implement local adaptation strategies Cascadia Focus. “Earthquake plus 30 minutes: strategies for people in the tsunami zone”
The invitation is to shift from thinking that this “might happen” and actually EXPECT IT! The challenge is to align our behavior with what we know will happen
Earth is like a Hard Boiled Egg
Cascadia Subduction Zone Its western edge runs North South off shore 90 (+/-) miles From Northern California to Vancouver Island, BC. < Astoria < Eugene
Oregon Gets Earthquakes !
Source: 2010 issue of Cascadia
How Do We Know ? ► “Turbidites” are deposits of material that accumulate in the sediments of sea canyons. ► Each great earthquake shakes material off the sides of the canyons. ► Over time, these build as layers whose size and frequency indicate the size and frequency of CSZ events. ► Chris Goldfinger, OSU
Source: Atwater (2005);
Core Sampling Device
Sediment Cores from Deep Ocean Canyons Provide a 10,000 Year Record of Events Source: Chris Goldfinger, Oregon State University
Paleo-seismology Onshore record Young’s Bay, OR Evidence of the last four Cascadia events, estimated top to bottom as AD:
T19 Cascadia: The Movie This sequence shows the Cascadia Holocene earthquake sequence. The slides are timed at 1 sec ~ 200 years. Event pulses that correlate at all sites are shown by flashes of the “locked zone” in red. Event “size” shown by intensity of red shading
T18
T17a
T17
T16a
T16
T15a
T15
T14a
T14 Crater Lake (Mt. Mazama) Goes off!! ~7625 BP
T13
T12a
T12
T11 Biggest Cascadia Earthquake! ~ 5900 BP
T10f
T10d
T10c
T10b
T10a
T10 End of a 1200 year Gap in the North ~ 4800 BP
T9a
T9
T8
T7a
T7 Land Paleoseismic Begins ~ 3000 BP
T6a Northern San Andreas Fault
T6
T5c
T5b
T5a
T5 Another ~ 1000 year Gap (north only) Ends ~ 1500 BP
T4a
T4
T3a
T3
T2a
T2 The penultimate earthquake ~ 480 BP
T1 (AD 1700)
The Bottom Line ► Giant Earthquakes Happen Here! ► They Occur Regularly in Geologic Time ► Our Last one Was in 1700 (315 years ago) ► Given 10,000 year Averages, We’re Due ► EXPECT IT!
30 Year Probabilities of Selected Hazards USGS Press release 2008, adapted from “Earthquake Basics” DOGAMI 2013 * 54
Dice? Pick Two (2) Numbers, and Roll ‘Em 37% probability in the next 50 years of an M8 or M9 (1:3 = 2:6) Chris Goldfinger, OSU
The 3 Things You Need to Know ► Big earthquakes make big tsunamis. Know the difference between Local and Distant events. ► If you feel the earth quake, Get to high ground fast (15-30 min). Locate now the Danger Zones and Safe Zones where you live, work, and play. ► Instruct Loved Ones to get to high ground, stay there overnight, and find each other at a shelter. ID non-local contact person to call. Source: Patrick Corcoran, Sea Grant Extension, Oregon State University
Distant Tsunamis Caused by an earthquake elsewhere, non-lethal event
Local Tsunamis Created by a local earthquake
Earthquake First !
A large earthquake IS your warning that tsunamis are on their wayin 15 – 30 minutes!!
Local Tsunamis ► The areas vulnerable to surge and flooding by tsunamis include all beaches, shorelines, coastal waterways, and wetlands. Much development exists in these areas. ► Locate where you live, work, and play on Tsunami Inundation Maps (TIMs) and “know where to go” when the next Big One occurs. There will be no warning, you will have 15 – 30 minutes to get to high ground. Period. ► Evacuation Brochures portray the WORST case scenario for a LOCAL event. Get maps at city halls, fire stations, etc. Google: Oregon Tsunami Clearinghouse. Source: Patrick Corcoran, Sea Grant Extension, Oregon State University
New Maps ! ► Tsunami inundation maps (TIM): Show range of the inundations of the past 19 events. More nuanced. For planning purposes. ► Brochures: Worst case distant from (AK)
19 M9‘s in past 10,000 years !
How Do I Reconnect With Family? DISTANT No problem. Phones, roads and infrastructure may be busy, but intact. Drive home or stay overnight with “friends in high places.” ► LOCAL Big problem. Instruct loved ones to get to high ground, stay there overnight, and find each other later at a shelter. ID a non-local contact person for everyone to call. Do not rush to meet at a designated place as that will likely require family to re-enter danger zones. ► Power and all phones will be out. Roads and bridges will be destroyed. You will likely not be in communication for a while. Insist that everyone knows what to do to be safe wherever they are. Don’t re-enter inundation zones for 12 hours. Talk through these scenarios. Source: Patrick Corcoran, Sea Grant Extension, Oregon State University
Families and Loved Ones ► Do your loved ones understand this infrequent but real hazard? Do they Expect it? ► Will they take distant events in stride; but when the earth quakes move to high ground, stay there overnight, and find you the next day? Are you sure?
Overwhelming Opportunities ► Political leadership and government support ► Businesses and Chambers of Commerce ► Schools, hospitals and public heath ► Public works, ODOT, planning departments ► Individuals, families, and neighborhoods, CERTS.
Employees ► Workplace policies ► Insurance coverage ► Fleet considerations ► Go Bags in cars ► Contact strategies ► Non-structural improvements ► Owner? Tenant? ► Continuity Planning ► Oh, my!
Tips for ODOT Field Staff ► Familiarize yourself with inundation maps for where your work locations and travel routes. ► Sharpen your eye with regard to vulnerable areas and safe areas. Go Bags in rigs? ► Talk to your colleagues about your shared physical risks and personal risk tolerance.
Two Tsunami Scenarios ► Distant: Where are you? Inundation zone? What do you do? When will you be able to reconnect with loved ones? ► Local: Where are you? Inundation zone? What do you do? When will you be able to reconnect with loved ones?
We’re Culturally Unprepared ► Research has only in the past 25+ years revealed that Cascadia erupts in Great (M9) earthquakes and tsunamis. ► It’s understandable that we’re behind the curve. But, we must make up for lost time. We must prepare commensurate with the risk—which is great. ► In Japan 2011, 20k people tragically died. But over 200k were in the inundation zone at the time. So, 90% of Japanese successfully evacuated!
Plan B