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U. S. Geological Survey Earthquake Program Geodesy and Deformation Activities

U. S. Geological Survey Earthquake Program Geodesy and Deformation Activities. Ken Hudnut, Jess Murray, Mal Johnston and John Langbein with contributions by Nancy King & Evelyn Roeloffs SESAC Meeting Paso Robles Inn September 5, 2007. Order of Presentations.

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U. S. Geological Survey Earthquake Program Geodesy and Deformation Activities

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  1. U. S. Geological SurveyEarthquake ProgramGeodesy and Deformation Activities Ken Hudnut, Jess Murray, Mal Johnston and John Langbein with contributions by Nancy King & Evelyn Roeloffs SESAC Meeting Paso Robles Inn September 5, 2007

  2. Order ofPresentations Ken Hudnut - brief program background Malcolm Johnston - borehole strain John Langbein - incl. external program Jessica Murray - including the past/present/future of Menlo Park GPS Ken Hudnut - SoCal & real-time GPS testing Take-home points - contributed by all (including Nancy King & Evelyn Roeloffs)

  3. Mission statement The U.S. Geological Survey (USGS) Earthquake Hazards Program monitors the Nation’s earthquakes, studies why they occur and how they shake the ground, provides quantitative earthquake-hazard assessments, helps promote loss-reduction measures using these results, and provides crucial scientific information to assist emergency responders when earthquakes occur. Geodetic observations and research are required to fulfill the USGS Earthquake Program mission

  4. NEHRP - USGS Role The four main NEHRP objectives for the USGS are: 1) Improve quantification of seismic hazards. Geodetic observations and research are required to quantify the long-term strain accumulation and release along active fault systems.Although geodetic data are only included indirectly at the present time, future National Seismic Hazard Maps will include geodetic data explicitly in the computed earthquake probabilities. 2) Complete the modernization and expansion of real-time earthquake notification and monitoring systems. Geodetic observations are required for rapid assessment of the earthquake source. Finite fault source models now typically rely upon near and intermediate field GPS data (continuous and survey-mode) to constrain the fundamental aspects of the earthquake source. 3) Achieve better scientific understanding of earthquake processes and effects. Geodetic observations are required for understanding the range of earthquake-related phenomena between seismic and geologic temporal bands. Research using geodetic data have historically provided insight into earthquake processes and effects; this is expected to continue into the future. 4) Provide national and local leadership to engage communities in earthquake safety practices.

  5. Stafford Act - USGS role 42 U.S.C 5201 et seq. The Disaster Relief Act of 1974, Section 202(a), states that: "The President shall insure that all appropriate Federal agencies are prepared to issue warnings of disasters to State and local officials." In addition, Section 202(b) states that "The President shall direct appropriate Federal agencies to provide technical assistance to State and local governments to insure that timely and effective disaster warning is provided." The Director of the Geological Survey, through the Secretary of the Interior, has been delegated the responsibility to issue disaster warnings "...for an earthquake, volcanic eruption, landslide, or other geologic catastrophe."

  6. Order ofPresentations Ken Hudnut - brief program background Malcolm Johnston - borehole strain John Langbein - incl. external program Jessica Murray - including the past/present/future of Menlo Park GPS Ken Hudnut - SoCal & real-time GPS testing Take-home points - contributed by all (including Nancy King & Evelyn Roeloffs)

  7. Order ofPresentations Ken Hudnut - brief program background Malcolm Johnston - borehole strain John Langbein - incl. external program Jessica Murray - including the past/present/future of Menlo Park GPS Ken Hudnut - SoCal & real-time GPS testing Take-home points - contributed by all (including Nancy King & Evelyn Roeloffs)

  8. Order ofPresentations Ken Hudnut - brief program background Malcolm Johnston - borehole strain John Langbein - incl. external program Jessica Murray - including the past/present/future of Menlo Park GPS Ken Hudnut - SoCal & real-time GPS testing Take-home points - contributed by all (including Nancy King & Evelyn Roeloffs)

  9. Order ofPresentations Ken Hudnut - brief program background Malcolm Johnston - borehole strain John Langbein - incl. external program Jessica Murray - including the past/present/future of Menlo Park GPS Ken Hudnut - SoCal & real-time GPS testing Take-home points - contributed by all (including Nancy King & Evelyn Roeloffs)

  10. USGS GPS needs • USGS Stafford Act real-time hazard alerts • L1 C/A single frequency or P(Y)-code dual-frequency are inadequate for USGS needs • USGS requires precise (cm) positioning in real-time (e.g., dual-frequency phase-differential GPS) • Modernization will take time • L2C, L5, L1C • Real-time accuracy and robustness limitations • Ambiguity resolution • Multipath (range & carrier) • High cost of software • Limited availability and high cost of most precise orbit & clock correction data • More demanding future USGS users’ applications for alerts S/A off meant GPS became adequate for USGS users except those who rely on it for forming input to hazard alerts USGS needs precise real-time displacements

  11. USGS Future Capabilities • Earthquake Early Warning System (testing has started) • GPS augments seismic array in real-time • Slip sensor array to detect fault slip • Volcano Alerts • Deformation monitoring in real-time • Aircraft ash warnings • USAID IOTWS with NOAA - GPS displacements for operational tsunami alert systems - recent GRL and EOS concept and advocacy articles • Require robust real-time centimeter accuracy, yet currently this is either infeasible or cannot be afforded by USGS

  12. Lone Juniper Ranch and Frazier Park High School Prototype GPS fault slip sensor Spans the San Andreas fault near Gorman, California Need robust GPS at all key lifeline crossings Desirable to include seismic with GPS

  13. Real-time GPS PPP developed by JPL with NASA funding Real-time StarFire Post-processed (TRACK)

  14. Real-time GPS PPP developed by JPLwith NASA funding Testing of PPP at UCLA Factor Bldg. - NavCom, JPL RTG Step tests and other basic testing have revealed issues of gross errors, delayed convergence, noise USGS requires robust and precise real-time GPS results; inertial aiding

  15. San Andreas - need to at least instrument major lifeline infrastructure crossings L A GPS & accelerometer arrays - no funding has yet been identified for an operational system

  16. Proposal - zipper array for early warning and immediate finite-fault source for San Andreas and San Jacinto fault ‘Big Ones’ L A IOC - 36 quadrilaterals shown @ 30 km spacing (shown) FOC - 100 quads @ 10 km spacing ($5 M init. + $1 M/yr)

  17. LiDAR & InSARUSGS investigators have developed strong in-house capabilities; early work with partners was effective Courtesy of M. Bevis, OSU Courtesy of G. Peltzer, JPL & UCLA

  18. Order ofPresentations Ken Hudnut - brief program background Malcolm Johnston - borehole strain John Langbein - incl. external program Jessica Murray - including the past/present/future of Menlo Park GPS Ken Hudnut - SoCal & real-time GPS testing Take-home points - contributed by all (including Nancy King & Evelyn Roeloffs)

  19. Obtaining and using real-time multi-parameter deformation data is essential to meeting the USGS hazard reduction responsibilities. • We have to opportunity to position ourselves as a leader in this field. • Establishing collaborations with other groups will help us reach this goal. • We must have robust data access and the capability to process the data without depending on others. • The role of PBO in USGS monitoring and response must be defined. • USGS will rely on the significant instrumentation infrastructure provided by PBO. • PBO is not a solution to real-time monitoring as is but could be leveraged. We need: • robust telemetry • more frequent data access (with goal of real-time) • Data quality is still an issue for some strainmeter sites. • Adequate staff and monetary support must be allocated in order to fulfill our monitoring and response role. • USGS instruments have been in steady decline, in part due to lack of personnel and funds for maintenance. • The skills and tools are available to accomplish many of the monitoring and response goals outlined here, but we lack the staff to • implement tools • monitor an increasing number of sites • We must define the level at which we will endeavor to fulfill our monitoring and response duties. • Several geographic regions (e.g., PNW, central U.S.) are not routinely monitored with GPS by USGS personnel. • We must maintain our scientific program in parallel with monitoring and event response. • Many of the same staff who conduct monitoring are also responsible for fundamental research. Conclusions

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