Preparing ODOT Geo-Enviros for Earthquakes and Tsunamis

Patrick Corcoran, Associate Professor, OSUHazards Outreach Specialist, Oregon Sea Grant Extension

Seaside, OR Undated Sendai, Japan 3.11.11

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 !

PNW Earthquakes & Tsunamis:Local event scenarios

1. Cascadia Subduction Zone earthquakes: 1700

2. Deep intraplate earthquakes: 1949, 1965, 2001

3. Shallow earthquakes: 900, 1872, 1992, 1993

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); http://pubs.usgs.gov/pp/pp1707/

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:

17001400900400

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 CraterLake(Mt. Mazama)Goes off!!~7625 BP

T13

T12a

T12

T11BiggestCascadiaEarthquake!~ 5900 BP

T10f

T10d

T10c

T10b

T10a

T10End of a1200 yearGap in theNorth~ 4800 BP

T9a

T9

T8

T7a

T7LandPaleoseismicBegins~ 3000 BP

T6a

NorthernSan Andreas Fault

T6

T5c

T5b

T5a

T5Another~ 1000 yearGap (north only)Ends~ 1500 BP

T4a

T4

T3a

T3

T2a

T2The penultimateearthquake~ 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

Outcome:

30-year Probability of Occurrence

Being In A Car Accident 59.9%50-year old Oregon Male Will Die 40.3%

50-year old Oregon Female Will Die 27.1%At Least One 100-year Flood 26.0%

30-year old Oregon Male Will Die 10.8%Magnitude 8-9 Cascadia Subduction Earthquake & Tsunami 10.0%

Your Vehicle Stolen 9.5%30-year old Oregon Female Will Die 6.4%

You Are Robbed 3.0%Have Residential Fire 1.2%Killed In Car Accident 0.9%

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 TsunamisCaused by an earthquake elsewhere, non-lethal event

Local TsunamisCreated by a local earthquake

Earthquake First !

A large earthquake IS your warning that tsunamis are on

their way in 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