Earthquakes and GPSWhat’s next?

Dr. Ken HudnutDr. Ken HudnutChief, 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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Thank you!Thank you!• Joe Sass for letting me borrow his Joe Sass for letting me borrow his

laptop and saving me!laptop and saving me!

• Brian Hess for inviting me!Brian Hess for inviting me!

• San Bernardino – Riverside Chapter of San Bernardino – Riverside Chapter of CLSA for having me here!CLSA for having me here!

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Plenty of eq.’s to study and new data

• Landers 1992 Landers 1992 (including Joshua Tree (including Joshua Tree and Big Bear)and Big Bear)

• 1994 Northridge1994 Northridge• 1999 Hector Mine1999 Hector Mine

• 250+ SCIGN stations250+ SCIGN stations• CMM3 available nowCMM3 available now• Total of over 60 Total of over 60

publications using publications using SCIGN data so farSCIGN data so far

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1st Year• Combined time

series (1996-2002)

3rd Year• Real-time earth-

quake response

5th Year• Resolve rates on

primary LA basin

faults (and others)

SCIGN Data Products

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1st Year• Complete and

distribute CMM3

3rd Year• Integrate InSAR

with GPS forvertical defor-mation rates

5th Year• Resolve rate dis-

crepanciesbetween geologyand geodesy

SCEC Tectonic Geodesy

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Los Angeles metropolitan region

• Bawden et al., 2002 Bawden et al., 2002 NatureNature paper paper

• Seasonal variations Seasonal variations in SCIGN data in SCIGN data correlated with water correlated with water table changestable changes

• Removal of this Removal of this noise enabled a noise enabled a refined velocity map refined velocity map for the urban areafor the urban area

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LA hazards• Must integrate many Must integrate many

types of informationtypes of information

• Combine GPS with Combine GPS with the deep fault the deep fault geometry (from geometry (from imaging and imaging and seismicity, etc.) and seismicity, etc.) and 3D structure3D structure

• Employ novel Employ novel modeling methodsmodeling methods

D. Argus, JPL

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Improving hazard assessmentImproving hazard assessment

• Temporal variations do Temporal variations do occur:occur:• Clustering (e.g., Basin & Clustering (e.g., Basin &

Range, ECSZ, Asia)Range, ECSZ, Asia)• Discrepant geological Discrepant geological

and geodetic ratesand geodetic rates• Sequences involving Sequences involving

fault interaction (e.g., fault interaction (e.g., Joshua Tree - Landers - Joshua Tree - Landers - Big Bear - Hector Mine; Big Bear - Hector Mine; Anatolian system, etc.)Anatolian system, etc.)

• Implement robust Implement robust research findings into research findings into hazard assessmenthazard assessment

Courtesy Anke Friedrich

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Fault interaction studiesFault interaction studies

• Emerging view of Emerging view of large events as a large events as a composite of sub-composite of sub-events or asperitiesevents or asperities

• Dynamic triggeringDynamic triggering• Static triggeringStatic triggering

• Important to study Important to study analogous eventsanalogous events

• Cascading rupture - Cascading rupture - order in chaos?order in chaos? Bayarsayhan et al., 1996

Kurushin et al., 1998

1857 San Andreas

1957 Gobi-Altay

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Serkan Bozkurt, Tom Fumal, & Ross Stein, USGS

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NW SJF Scenario Stress Changes

Greg Anderson, USGS

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SJF event with jumpingSJF event with jumping

Brad Aagaard, USGS

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New methods and data integration

• precise topographic mapping of surface ruptures and active fault scarps

representation of actual fault ruptures recorded and preserved in unprecedented detail

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

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Laser scanLaser scanof the San of the San AndreasAndreas

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What is EarthScope?What is EarthScope?

USArray• 400 station transportable array “big foot”• ~2400 instrument flexible array

PBO • 875 permanent GPS stations• 175 borehole strainmeters/seismometers• 100 campaign (portable) GPS systems• 5 laser strainmeters• Data and data products

SAFOD • 4-km-deep scientific drilling project into the San Andreas fault zone near Parkfield

Fully open data policy

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What is PBO?

•Backbone of 100 new and 20 existing permanent stations

•775 permanent cluster GPS stations

•147 volcanic stations

•628 tectonic stations

• 175 borehole strainmeters

• 100 campaign GPS systems

• 5 laser strainmeters

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What is PBO?

•Nominal data set – 30 sec data file downloaded daily

•Potential data sets

•1 sec real time

•5 Hz on-demand

•Two full-time data processing centers

•Two full-time archive/distribution centers

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What is PBO?

•Five year build out phase

•Five year O&M phase

•Total 10-year operational commitment

•Probable start date 1 September, 2003

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•Six regional offices in Alaska, Pacific NW, Basin & Range, Rocky Mtns, Southern and Northern California.

•Each region has dedicated resources for recon, permitting, installation, maintenance, and data flow.

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PBO in Southern California

•~170 new continuous GPS stations

•~64 borehole strainmeters

•Full time staff of six personnel located in Southern CA.

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Station Breakdown by County

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•125 SCIGN stations proposed for support under NSF existing networks proposal

•After 5 years SCIGN stations transition to PBO operations and maintenance

PBO and SCIGN

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Help! Mike Jackson, Help! Mike Jackson, UNAVCO – PBO DirectorUNAVCO – PBO Director

•How can you help?

•Assist in siting, reconnaissance, and permitting efforts for GPS and strainmeter stations in Southern California

•Help with points of contact for PBO personnel in Southern California

•What can we do for you?

•Provide equipment, operations and maintenance support, and data for for new PBO station installations in Southern California