WORKSHOP ON APPLICATION OF REMOTE SENSINGTECHNOLOGIES FOR DISASTER RESPONSEBeckman Center of the National AcademiesIrvine, California 12 September 2003

Earthquake Remote SensationKenneth W. Hudnut, Ph.D.Kenneth W. Hudnut, Ph.D.Chief, So. Calif. Earthquake Hazard Assessment ProjectChief, So. Calif. Earthquake Hazard Assessment ProjectEarthquake Hazards Team Earthquake Hazards Team U. S. Geological SurveyU. S. Geological Survey

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The San Andreas FaultThe San Andreas Fault

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San Andreas faultSan Andreas fault•• 35 mm/yr slip rate;35 mm/yr slip rate;

•• >70% of total plate >70% of total plate boundary motionboundary motion

•• 1685, 1812, 18571685, 1812, 1857 eq’seq’s•• Big Bend compressionBig Bend compression

•• 1971 Sylmar (M 6.7)1971 Sylmar (M 6.7)•• 1994 Northridge (M 6.7)1994 Northridge (M 6.7)

•• SoCal SoCal is now heavily is now heavily ‘wired’ (much like ‘wired’ (much like Japan & Taiwan)Japan & Taiwan)

•• 150+ BB CISN stations150+ BB CISN stations•• 250+ SCIGN stations250+ SCIGN stations•• Catalog; SCEC CMM3Catalog; SCEC CMM3

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Southern California is the nation’s most Southern California is the nation’s most dangerous place for earthquakes dangerous place for earthquakes -- why?why?

Silver linings:State-of-the-art earthquake monitoring arraysMany of the world’s best researchers work within this natural laboratory

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GPS is now vital to earthquake monitoring(array technology and GPS satellites weredeveloped in Southern California)

GPS is now vital to earthquake monitoringGPS is now vital to earthquake monitoring(array technology and GPS satellites were(array technology and GPS satellites weredeveloped in Southern California)developed in Southern California)

Measures buildup of strain on faults due to accumulating Measures buildup of strain on faults due to accumulating tectonic motiontectonic motion

Used to detect damage to large engineered structures Used to detect damage to large engineered structures such as dams, and effects of ground tilt and subsidence such as dams, and effects of ground tilt and subsidence on water systemson water systems

Can be used in realCan be used in real--time to detect fault slip at surface, for time to detect fault slip at surface, for early warning systemearly warning system

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GPS

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SCIGN array infrastructure

250 telemetered GPS stations (dual-frequency)

• 30 second data rate• variable latency

Upgrades in progress• 1-second, real-time

Supports highly precise geo-referencing, even in real-time (on aircraft)

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Infrastructure for positioningsupports data collection and mapping

during disaster recovery efforts imageryimagerybefore &before &afterafter

Courtesy of Ron Eguchi

Courtesy of City of Glendale

ATC-20 building safety inspectionsATC(red, yellow and green tagging)ATC--20 building safety inspections20 building safety inspections(red, yellow and green tagging)(red, yellow and green tagging)

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Earthquakes are Earthquakes are not onlynot only California’s problemCalifornia’s problem$30M of oil each day!

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Earthquakes are a global problemEarthquakes are a global problem

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Striving for higher resolutionStriving for higher resolutionand betterand better georeferencinggeoreferencing

SRTMGTOPO30

Platforms: satellite, high-altitude drone, airborne (fixed wing, helicopter),even tripod-mounted (e.g., laser scanner)

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ALSM, InSAR and TM imagingALSM, InSAR and TM imagingand mapping before & afterand mapping before & after Laser scan of land

surfaces and urbaninfrastructure –buildings & lifelines- damage assessment

Pre- and post-disaster images can be differenced to measure damage and track recovery

LANDSAT 7 on SRTM showing earthquake damage - Bhuj, India

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New methods and data integrationNew methods and data integration•• Precise Precise

topographic topographic mapping of mapping of surface ruptures surface ruptures and active fault and active fault scarpsscarps•• slip models for slip models for

prehistoric eventsprehistoric events•• rapid assessment rapid assessment

of surface slip and of surface slip and damage patterns damage patterns after large eventsafter large events

•• Requires precise Requires precise integration of GPS integration of GPS & INS for flight & INS for flight navigation

1957Gobi-Altaiearthquakesurfacerupture

navigation

High resolution topography along surface rupture of the High resolution topography along surface rupture of the October 16, 1999 Hector Mine, California Earthquake (MOctober 16, 1999 Hector Mine, California Earthquake (Mww7.1) 7.1) from Airborne Laser Swath Mappingfrom Airborne Laser Swath Mapping

Hudnut, K. W. (USGS), A.Hudnut, K. W. (USGS), A. Borsa Borsa (UCSD),(UCSD),C.C. Glennie Glennie ((AerotecAerotec, LLC) and J., LLC) and J.--B. Minster (UCSD)B. Minster (UCSD)

Bulletin of the Seismological Society of AmericaSpecial Issue on the Hector Mine earthquake (2002)

http://pasadena.wr.usgs.gov/office/hudnut/docs/

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Katherine Kendrick, USGS

Chris Walls, Earth Consultants International

‘A rip in the desert canvas’- Los Angeles Times

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Airborne laser swath mapping (ALSM)

• precise topographic mapping of surface ruptures and active fault scarps

Airborne platform navigationmust be highly precise andrequires high-rate GPS data

• representation of actual fault ruptures recorded and preserved in unprecedented detail

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Geolocation Vectors and Error Sources

R r

v

r

Vector from CMearth to GPS phase centerMagnitude & directional errors both arestochastic, time and location variant.

R

vVector from GPS phase center to laserMagnitude error is constant if no airframe flexing. Directional error due to constant and time-varying biases in INS.

Vector from laser to ground footprintMagnitude error due to timing, instrument and atmospheric delays. Directional errorfrom constant mirror mounting offsets and time-varying biases in reporting of scanangles (both pitch and roll).

Note: additional errors due to imperfectsynchronization of GPS, INS, mirror scanand laser firing times must be modeled and removed as well.

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Explodedordnance(crater)

pitch maneuvers

Lavic LakeRoll & PitchManeuvers

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Maximumslipsectionof the1999HectorMine eq.surfacerupture

Photo byKeith Stark(SCIGN)

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QuickTime™ and a DV/DVCPRO - NTSC decompressor are needed to see this picture.

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Estimating Estimating slip on slip on ‘max. slip’ ‘max. slip’ segment ofsegment ofthe faultthe fault

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Laser ScanLaser Scanof the San of the San AndreasAndreasProposal to theNSF EarthScopeScience RFP:Prof. Mike Bevis, PI (OSU)

Requireshigh-rate (1 Hz)GPS datafrom SCIGNsites alongfhe fault &special carewith IMU-INS

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The National Map: Public Safety

Selected HazardsMajor earthquakes 1983-2003Volcanoes – Potentially activeWildfires reported to Federal agencies – 2001 Major hurricane tracks since 1850

Other Concerns125 mile buffer from America’s bordersWatersheds around urban areas

Urban AreasMajor urban areasOther cities and places with special concerns

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The National Map: Infrastructure

Selected InfrastructureUrban areasRoadsRailroadsPipelinesAirports, dams, and power facilitiesMilitary reservationsOther Federal engineering sites

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Future developmentsFuture developmentsGlobalhawk

Real-timeGPS arrays Precise georeferencing of pre-

and post-event imagery datais made possible by fixed GPSarray at high data rate

Maps2MEFutureRoads

StarFire NAVCOM globaldecimeter real-time GPS

AIMS and other GPS/INS integration

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Conclusions:Conclusions:•• GPS and inertial sensor integration for highGPS and inertial sensor integration for high--

accuracy applications is practical inaccuracy applications is practical in SoCal SoCal because SCIGN can be readily upgraded to because SCIGN can be readily upgraded to support centimetersupport centimeter--level accuracy in reallevel accuracy in real--timetime

•• Earthquake applications of ALSM Earthquake applications of ALSM & GPS/INS integration are:& GPS/INS integration are:

•• societally societally relevant relevant -- significant significant economic impact and economic impact and consequences would result from consequences would result from technological innovationstechnological innovations

•• scientifically exciting for the very scientifically exciting for the very dynamic SCEC research dynamic SCEC research community community -- major breakthroughs major breakthroughs in earthquake source physics are in earthquake source physics are likely to result from collaborationslikely to result from collaborations