The Use of GPS for Earthquake Hazard Response and Research at USGS

Seismic and Tsunami Threats to Southern California

Nancy King, Ph.D. U.S. Geological SurveyPasadena Field OfficeNorthridge earthquake 1994

Northridge earthquake, 1994Emergency Response Readiness WorkshopJoint Forces Training Base, Los Alamitos, CaliforniaMay 10, 2012Plate Tectonics and Earthquakes

Faults and Plate Tectonics

Plate motion occurs on faults.

What Faults Look Like After Earthquakes

1906 San Francisco earthquake

1979 Imperial Valley earthquake

Scarp of 1971 San Fernando earthquakePhoto fromFinding Fault in California: An Earthquake Tourists Guide,by Susan Elizabeth Hough

Landers earthquake, 1992Faults and Shaking

An earthquake is sudden slip on a fault.

This slip triggers seismic waves.

These waves cause shaking and most of the damage.Seismic Waves

Seismogram

Faults and Earthquakes of the Western U.S.

What the San Andreas Fault Looks Like

Stream offset:420 feet in 3800 yearsFaults of Southern California

Over 300 faults inSouthern CaliforniaOnly the San Andreas can have the Big One (M 7.8+)

But earthquakes on other faults can be disasters, e.g. 1994 Northridge M 6.7But other faults can producedamaging earthquakes

Magnitude and Intensity

Magnitude is the maximumamplitude on a seismogram.

Worldwideneic.usgs.gov/neis/eqlists/eqstats.htmlDoug Given, USGS

The magnitude scale is logarithmic.Each whole number increase is:

10 times more ground motion32 times more energyIntensity is the earthquakes effects,on scale of I to XII. Depends on: Distance from earthquake Geology Type of structure Observer!Varies from place to place.Earthquake History of S. California

Earthquakes in California

1930200750,000Good seismicnetwork begins here.On average in southern California:Over 30 per day, mostly not feltMagnitude 6 every 5 yearsMagnitude 7 every 30 yearsMagnitude 7.7 every 150 yearsWe CANNOT predict these earthquakes!13Earthquake Effects Aftershocks

March 11, 2011 Tohoku M 9.0 earthquake and its aftershocks in the first dayEarthquake Effects - Structure Failure

Ferndale, CA, M 7.1 1992Life-safe

Columbia, M 6.2, 1999NOT life-safe

Northridge, CA,M 6.7 1994Performance depends on Material ConstructionEarthquake Effects - Falling Objects

Stanford University, 1906 earthquakeEarthquake Effects - Utility Line Rupture

USGS Open FileReport 96-263

Northridge earthquake,1994Earthquake Effects - Lifelines

L AHighways, railways, power lines, phone lines, pipelines, and wateraqueducts and pipelines all cross the San Andreas fault

Earthquake Effects - Interior Damage

Dr. Cindy Stern

Earthquake Effects Landslides and Liquefaction

Landslides Northridge, 1994

Steinbrugge Collectionof the UC BerkeleyEarthquake EngineeringResearch CenterLiquefaction Niigata, Japan, 1964

Earthquake Effects - Tsunamis One or more intense waves, usually caused by an earthquake or undersea landslide.

First wave may NOT be the largest. Timing between waves may vary from minutes to several hours apart. The danger lasts hours after the first wave.

Tsunami waves can come ashore in different ways: Wall of water rapidly rising tide series of surf-like breakers

Tsunamis can carry boats, debris and heavy rocks.

Types: Local earthquakes near the coast where first wave can be within 10 minutes and may not be time for a tsunami warning Pacific-wide caused by earthquakes far away from our coast which allows time for an tsunami warning

Vulnerable areas in so. California include: LA and Long Beach Harbor, Venice and West Los Angeles beaches.

TSUNAMI WARNING BROADCAST: Pack up your family and pets and move inland

Earthquake Effects Tsunami in Hawaii, 1946

Hilo, Hawaii, 1946Earthquake Effects - Community

Death and injuryStructure damageNo power/gasFireNo waterRoad/rail closuresPhones out

No emergency servicesStranded commutersSeparated familiesDestroyed homesStores closedBusiness lossesLoss of jobs

The Big One

The last Big One in southernCalifornia was the Fort TejonEarthquake of 1857, which killed 2 people. No one remembers this earthquake.The next Big One will be different, causing casualties and damage in now heavily populated southern California. There will be up to 2 minutes of ground shaking.Preparation and response are local.Its up to us.Earthquake Deaths

Roger Bilham, University of ColoradoJapan 2011Earthquake Preparedness and Response

Retrofit buildingsSecure fixtures/contentsEmergency planEmergency suppliesCheck for damage and injuriesFollow your emergency planExpect aftershocksContact insurance agentRestore documentsBegin repairsContact FEMABeforeDuring Drop, cover,and hold on!After

USGS Products

CISN Display Real time earthquake alert and notification

California-Nevada Earthquake MapEarthquake Notification System

ShakeCast Situational awareness toolfor emergencyresponders andcritical facilityoperatorsUSGS Products

Did You Feel It?ShakeMap

The Take-Home Message

We live in earthquake country!Its up to each of us to prepare.Thank you!Questions?