M. Demirdjian, B. Mckenzie, D. Perera, J. Reschke, D. Rodriguez, C. Sandoval, A. Siripaisan, K. Vargas, J. Ying “ShakeOut Scenario”

Shake And Bake

BY:GPS Group

M. Demirdjian, B. Mckenzie, D. Perera, J. Reschke, D. Rodriguez, C. Sandoval, A.

Siripaisan, K. Vargas, J. Ying

“ShakeOut Scenario”

Plate Tectonics

History of San Andreas Earthquakes

Southern California Integrated GPS Network

(SCIGN)

North GPS Data

1/6/2

004

6/15/2

004

11/23/2

004

5/3/2

005

10/11/2

005

3/21/2

006

8/29/2

006

2/6/2

007

7/17/2

007

12/25/2

007

6/3/2

008

11/11/2

008

4/21/2

009

9/29/2

009

3/9/2

010

8/17/2

010

1/25/2

011

-20

-15

-10

-5

0

5

10

15

20

f(x) = 0.0100398493050884 x − 392.704615017112R² = 0.968316734130431

Series1Linear (Series1)

Date

mm

1/6/2

004

6/15/2

004

11/23/2

004

5/3/2

005

10/11/2

005

3/21/2

006

8/29/2

006

2/6/2

007

7/17/2

007

12/25/2

007

6/3/2

008

11/11/2

008

4/21/2

009

9/29/2

009

3/9/2

010

8/17/2

010

1/25/2

011

-20

-15

-10

-5

0

5

10

15

20

25

f(x) = 0.00955981759376252 x − 373.873900244331R² = 0.927006159964529

Series1

Linear (Series1)

Date

mm

East GPS Data

Dr. John Dye(Math Department)

Crack (Fault) Model

Displacement at GPS station from the fault

Fault and Displacement Theory

QUAKESIM & JPL

Displacement

GPS station data can show us the amount of displacement of the ground

after an earthquake.

Displacement

INTRODUCTION

ELASTIC REBOUND THEORY

• After the devastating 1906 San Francisco earthquake, Geology Professor Henry Reid concluded (after examining the displacement of the ground surface) that the earthquake must have involved an "elastic rebound" of previously stored elastic

stress.1

• “The gradual accumulation and release of stress and strain is referred to as the ‘elastic rebound theory’ of earthquakes. As plates on opposite sides of a fault are

subjected to force and shift, they accumulate energy and slowly deform until their internal strength is exceeded. At that time, a sudden movement occurs along the fault, releasing the accumulated energy, and the rocks snap back to their original

undeformed shape.”2

ELASTIC REBOUND THEORY

This picture demonstrates the elastic rebound theory. The two plates are subject to force over a long period of time and begin to deform. Eventually enough energy is accumulated to break the two plates apart along the fault. The two plates are permanently separated, but

revert to their original shapes.

ELASTIC REBOUND THEORY

Our stick-slip fault demonstration can be found on YouTube!

Information taken from: 1: http://earthquake.usgs.gov/regional/nca/1906/18april/reid.php2: http://en.wikipedia.org/wiki/Elastic_rebound_theory

Seismic Waves• Cause by breaking of rocks in the fault, which gives

off energy

• Recorded on the seismographs to measure the intensity.

• Traveling speed can vary based on the density and type of rock.

• Body waves and surface waves.

Oscilloscope & Transducer

Body WavesP and S wave

• P-wave (Primary wave)– The fastest traveling

waves, but not often felt.– Push-and-pull motion– Travels through solids,

liquids, and gases.– Can be detected by

Seismologists – Used in an early warning

system

• S-wave (Secondary or Shear wave)– Can be felt in an

earthquake.– Can only travel through

solids– Move the ground

perpendicular to the direction the wave is traveling.

– Slinky Demo!

Surface Waves Love and Rayleigh Wave

• Love wave– Fastest surface wave and

move the ground side to side.

• Rayleigh wave– Rolls along the ground and

move the ground up and down and side to side.

Intensity Scale

Moment Magnitude

Moment = Mo = GADG = shear modulus A = L*W = areaD = average displacement during rupture

Sediment-Filled Valleys Amplify Shaking

LiquefactionLiquefaction is a natural phenomenon that occurs when underground water is forced up, causing the surface soil to liquefy, creating an effect similar to quicksand. One of the main causes of liquefaction is earthquakes, due to the pressure generated by heavy seismic activity.

http://www.youtube.com/watch?v=ODTu3cZ2AVs

The ShakeOut ScenarioBy Lucile M. Jones, and others

(2008) USGS• Greatly affect 8 counties of So.

California

• 300 km (180 mi) rupture

• Magnitude 7.8

• 100 seconds of fault rupture

• Ground shaking for over 2minutes in many places!

• Disruption of critical lifeline infrastructure (freeway, internet, power and gas lines) along surface rupture; Slip of 3-4 meters at Cajon Pass (I-15)

Caltrans freeways (and major highways) fault

crossings

All lifelines Cross San Andreas Fault

Building Damage• 300,000 significantly damaged (1 in 16)

– repairs cost at least 10% of replacement cost

• 45,000 complete losses (1%)

• Unreinforced masonry buildings900 destroyed; loss of life near fault not retrofitted

• Older concrete buildings (most dangerous-rebar)– 50 collapses – 5,000 – 10,000 people in collapsed buildings – 100 red tagged buildings

• Woodframe buildings (most numerous) – 175,000 wood buildings significantly damaged

(1 in 25)

1994 Northridge CA

1992 M7.1 Mendocino

Long Beach 1933

Fire Following Earthquake

• Earthquakes cause fire disasters– Numerous simultaneous ignitions– Degraded fire-resistive building features– Reduced pressure in water mains– Saturated communications– Traffic impacts– More fires than firefighting capabilities…

• Study findings– 1,600 ignitions requiring a fire engine– 1,200 exceed capability of 1st engine– Northern Orange County & LA Basin:

conflagrations destroy 100s of blocks– 200 million square feet burnt

~ 1.5% of total building stock– No Santa Ana winds… not worst case– 900 of the 1,800 casualties are from fire

Fire risk greatest in areas with strong shaking and densely-packed wood buildings; many such areas in LA Basin and northern OR Counties

Where’s the Water??

Emergency Response Challenges

• Widespread need for help• Distant mutual aid• Widespread disruption of:

– communication– transportation and access– water pressure– hospital functionality– staffing

Earthquake Response will not be there for us

And that does not include Aftershocks

• Damaging earthquakes may occur fordecades after a magnitude 7.8– Some may be more destructive than the mag 7.8

mainshock– Some will be larger than Northridge– Will occur over wide area

• Simulations of realistic aftershocksequences for Scenario– Four aftershocks will be used in Golden

Guardian exercises:• Mag 7.2 ruptures through Inland Empire

toward Pasadena• Mag 7.0 ruptures from Salton Sea into

Imperial County• Mag 5.7 with epicenter in Rialto• Mag 6.0 disrupts newly restored rail lines in

Cajon Pass

Distribution of aftershocks in Scenario simulations

Sources of Economic Shock

Economic Losses

Direct: property damage &

business interruption

Indirect: ancillary damage & ripple effects

Building damagefrom ground motion

Transportation route closureand delays

Watershut-off

Power outage

Gasshut-off

Building damage from fire

Adjusted for double-counting/multiple sources

Are Californians Prepared?• March 5, 2010 Study by UCLA:

• Less than 20% have prepared their homes

• 40% have sufficient water

• Less than 20% have earthquake insurance

• 80% have first aid kits, flashlights, batteries

• 40% have no family emergency plan

• Less than 20% have a neighborhood plan

• Less than 50% have dust masks; rescue tools; supplies in car or work or CERT or first aid trained

Google Earth Tour

Special thanks to Dr. Steve Graves (Geography Department)

Shakeout Scenario “Disaster Equation”

Widespread Strong Ground Shaking+ Shaking of Long Duration =• 300,000 buildings significantly damaged

• Widespread infrastructure damage

• $213 billion damages

• 270,000 displaced persons

• 50,000 injuries

• 1,800 deaths

www.ShakeOut.org

The End?