Real World Applications of USGS EQ Science:

Stacy BartolettiDegenkolb EngineersStructural Engineers Association of WashingtonCascadia Region Earthquake Workgroup

EERI Seattle Fault EQ Scenario

Project Conceived in 1996 – Real Work Since 2001

Volunteer Team of Seismologists, Geologists, Engineers, Planners, Emergency Managers, and Social Scientists

Key Statistics

Economic Loss Due to Damage - $33B

Deaths > 1,600 and Injuries > 24,000

Buildings Destroyed – 9,700 and Unsafe to Occupy – 29,000

Recovery Period – Several Years

USGS Science – Ground Motions

Magnitude 6.7 EQ

Real Event – Seattle Fault has had 4 similar or greater events in past 3,000 years

Fault Runs Through Major Areas of Seattle and Bellevue

Peak Ground Acceleration

Magnitude 6.7

Modeled fault

I

Major Discoveries in Past 10 to 20 Years Using Latest Science

USGS Science Ground Motions

% gravity

0 75

SeattleSeattle

OlympiaOlympia

Ground Failure

Fault Rupture

Liquefaction

Landsliding

Lateral Spreading

Life Lines

Water and Wastewater

Liquid Fuel and Nat Gas

Electrical Power

Communications

Transportation Systems

Roads and Bridges

Rail

Airports

Ports and Ferries

WSDOT Bridge Seismic Retrofit Timeline (12/2004)

Phase 1 Superstructure

Phase 3 Multiple Columns

0

50

100

150

200

250

300

350

1990 2000 2010 2040 2050

$Mill

ion

s (2

004)

20602020 2030 2070

Phase 2 Major Bridges

& Single Columns

Current Funding

$4.7 Million/Year

WSDOT Bridge Seismic Retrofit Timeline (12/2004)

Phase 1 Superstructure

Phase 3 Multiple Columns

0

50

100

150

200

250

300

350

1990 2000 2010 2040 2050

$Mill

ion

s (2

004)

20602020 2030 2070

Phase 2 Major Bridges

& Single Columns

Current Funding

$4.7 Million/Year

WSDOT Bridge Seismic Retrofit Timeline (12/2004) (Courtesy of WSDOT)

Bridges with hollow core piles and Alaskan Way Viaduct are excluded.

Buildings

Unreinforced Masonry

Pre 1970 Tilt Up

4000+ Commercial Buildings with Extensive Damage

50,000+ Households Displaced

Essential Facilities

Schools

Hospitals

Fire Stations

Police Stations

Table 6-3: Expected Damage to Schools

Damage (in percent) County

No Damage Slight Moderate Extensive Complete

King County 23% 22% 29% 18% 8%

Pierce 64% 18% 12% 5% 1%

Snohomish 64% 14% 9% 3% 10%

Total Region 38% 20% 22% 13% 7%

Priority Recommendations

Independent State Seismic Safety Commission or Board

Implement Risk Reduction Plans for Critical Facilities

Retrofit High Risk Buildings

Protect the Transportation Infrastructure

CREW – Cascadia Scenario

M9.0 Earthquake Scenario

January 26, 1700 Last Rupture

Geologic Evidence for Return Periods of About 200 to 1000 Years

Key Subduction Zone Issues

Strong Shaking for Several Minutes

Long Period Ground Motions

Destructive Tsunami Will Hit Coast

Potential for Significant Aftershocks

Impacts to Various Regions

Coast – High Ground Motions, Significant Damage, Tsunami

I5 – Moderate Ground Motions, Tall Blds, Old Blds, NS Damage

East of Cascades – Minimal Ground Motions, Little Damage, Source of Recovery

Conclusions/Recommendations

Continue to Develop Understanding of Seismic Hazard

Assess Earthquake Impacts on Built Environment and Communities

Work to Reduce Earthquake Impacts on Built Environment and Communities

Expand Education and Public Outreach

Degenkolb Engineers