Proposal for LLNL Funding for Cooperative Research

3-D Evaluation of Ground-Shaking Potential in the Las Vegas Basin

John G. Anderson, and John N. Louie

Seismological Laboratory, University of Nevada, Reno

Project Description

BACKGROUND

Ground shaking from both nuclear tests and regional earthquakes have been recorded in the Las Vegas metropolitan area, as well as noted by residents. Sensible preparation for earthquake hazards as well as for any possible resumption of testing requires a thorough understanding of how large seismic sources in the region may produce ground shaking in the city. The city is largely underlain by a deep sedimentary basin, the Las Vegas basin. With up to a 4.5-km thickness of low-seismic-velocity material, this basin is expected to have a profound effect on the level and distribution of ground shaking within the overlying city.

RESEARCH PLAN

We propose a one-year cooperative research program, with the Test Readiness group at LLNL and with engineers and seismologists at UNLV, to investigate geological influences on the level of ground shaking to be expected in the Las Vegas basin from regional seismic events. Our main objective will be to combine existing geological, engineering, and seismic data into a series of detailed trial models for the structure and properties of the basin. The focus of these studies will be to determine the importance of basin response in Las Vegas as a contributor to the seismic hazard of the metropolitan area. It is recognized that one year of research on the issue will not be able to completely describe basin response effects. The research we propose is intended to focus on scoping the problem. If the results demonstrate that basin response is a significant issue for the seismic hazard, then we anticipate future studies will be needed to reduce the uncertainties in our capability to predict that hazard.

Together with Dr. Vasquez (Mackay, UNR) we suggest here to acquire and begin to operate up to 16 new dual-processor nodes for the Beowulf parallel supercomputing facility at UNR. The improved computer capacity is essential for computing synthetic elastic sedismogrmas at UNR. This is especially true for large 3-d basin models that include a regional source. With this increased capacity, we will be able to run LLNL's e3d code to perform ground-motion sensitivity tests on basin parameters. The e3d code will be prepared to run on the Beowulf facility. We will also conduct shallow shear-velocity surveys at a dozen sites that recorded strong ground motion in the basin.

All research will be carried out in close collaboration with personnel at Lawrence Livermore National Laboratory. This will include immediate sharing of project results, in both directions, as they become available.

Specific tasks include:

1. Selecting a suitable 3D database (if possible, compatible with familiar GIS systems) to encompass the velocity model information.

Accommodate P-, S- velocities, density, geological formation, and other information as a function of latitude, longitude, and depth.

Accommodate both velocity gradients and velocity discontinuities.

Allow for fault locations, input with a series of (x,y,z) locations, to bound basins and other velocity discontinuities.

Accommodate topography.

Accommodate scales from regional to small, shallow engineering site studies.

Accommodate tracking model features to publications or data sources.

Accommodate multiple hypotheses.

Accommodate discrete version numbers.

Maintain compatibility with present modes of input to the e3d computer code run by LLNL.

2. Reviewing existing published geophysical studies, and populating the Las Vegas basin velocity model.

• Review published velocity and other geophysical models at all scales.

• Review gray-literature velocity and other geophysical models at all scales.

• Contact engineering firms, etc. for experimental data and interpretations.

3. Conducting parameter tests with e3d and draft 3-d velocity models of how the strength and spatial distribution of ground motions is affected by:

• Crustal velocities.

• Crustal thickness.

• Basin depth.

• Deep basin velocities.

• Shallow engineering properties.

• Lateral heterogeneity within the basin.

Some of these tests will be conducted on smaller computers having single-processor architecture, for plane-wave inputs to a basin-only model, very long-wavelength regional models, or sources within or below the basin. The Beowulf computation facility is proposed to be enhanced at UNR to be able to handle the regional model including both NTS sources and the Las Vegas basin, for computations at low frequencies (up to 0.5 Hz?). Computations to higher frequencies, or assessing smaller-scale lateral variation effects, will be run at LLNL.

4. In collaboration with LLNL personnel, we will consider the following activities, but only to the extent that they appear that they will support a determination of the importance of basin effects on potential strong ground motions in Las Vegas. These activities all fall under the category of utilizing untapped data to improve structure and velocity models.

• Surface wave dispersion across southern Nevada from regional earthquakes and teleseisms.

• Interpret Landers, Big Bear, and Little Skull Mountain earthquake records.

• Interpret old NTS explosion data that is available.

• There is a considerable amount of untapped data that can also be used to support travel-time verification of velocity models and tomographic improvements, and to calculate receiver functions. This is considered unlikely to have any first-order impact on determining the importance of the basin response to strong motion, so these studies will be deferred to later years.

Aspects of this task that are focused on the western Great Basin region rather than on the immediate NTS or Las Vegas areas will be performed by Louie under a separate DOE Geothermal Program investigation.

5. Performing a dozen refraction microtremor surveys for shear velocity to 100 m depth, at sites that recorded strong motion from earthquakes in 1992.

STAFFING

John Anderson will have responsibility for overall project oversight at UNR. He will also undertake the interpretation of existing strong-motion records under task 4, and make evaluations of modeling results generated by the sensitivity studies. John Louie will perform tasks 1, 2, 3, and 5 with the help of the graduate students, and take responsibility for developing velocity model versions, and performing the computational sensitivity studies. Raj Siddhartan, though on the UNR budget, will collaborate with UNLV's effort to generate soil-column response spectra, for comparison against strong-motion and modeling results. One full-year seismology graduate student will be supervised by Louie to perform tasks 2, 3, 4, and 5. One full-year computer science graduate student will set up and manage the computational facility for task 3, assist with parallelization programming, and develop and populate model data base and GIS systems.

Biographical Sketch of John N. Louie

Seismological Laboratory 174, Mackay School of Mines

The University of Nevada, Reno, NV 89557-0141

(775) 784-4219; fax (775) 784-1833; louie@seismo.unr.edu

Professional Experience

Associate Professor of Seismology, Seismological Laboratory and Department of Geological Sciences, The University of Nevada, Reno; since January 1992. Responsibilities include undergraduate and graduate instruction, supervision of M.S. and Ph.D. degree candidates, and conducting a research program in seismology.

Assistant Professor of Geosciences, The Pennsylvania State University, University Park, Pennsylvania; Sept. 1987 to Jan. 1992. Responsibilities included undergraduate and graduate instruction, supervision of M.S. and Ph.D. degree candidates, and research in high-resolution seismology.

Recent Graduate Theses Directed

Ph.D. Thesis in Geophysics by Robert E. Abbott on ``Geophysical constraints on seismic hazard and tectonics in the western Basin and Range'' defended on 23 Aug. 2001.

Ph.D. Thesis in Geophysics by Abu M. Asad on ``Linearized and nonlinear travel time tomography for upper crustal velocity structure of the western Great Basin'' defended on 23 Jan. 1998.

M.S. Thesis in Hydrogeology by Ken Mela on ``Interpretation of stochastic hydrogeologic properties from seismic data'' defended on 14 Nov. 1997.

Ph.D. Thesis in Geophysics by Sergio Chavez-Perez on ``Enhanced imaging of fault zones in southern California from seismic reflection studies'' defended on 4 Aug. 1997.

M.S. Thesis in Geophysics by Zakir Kanbur on ``Seismic reflection study of Upheaval Dome, Canyonlands National Park, Utah'' defended on 17 July 1997.

Ph.D. Thesis in Geophysics by Sathish K. Pullammanappallil on ``Nonlinear optimization to estimate velocities and image reflectors from multi-offset seismic data'' defended on 14 Nov. 1994.

M.S. Thesis in Geophysics by William Honjas on ``Results of post- and pre-stack migrations imaging the Hosgri Fault, offshore Santa Maria Basin, CA'' defended on 1 April 1993.

Selected Recent Sponsored Research

Assembly of a crustal seismic velocity database for the Western Great Basin, sponsored by the US Dept. of Energy/Great Basin Center for Geothermal Energy 4/02-3/03 for $144,584.

Evolution of the Sierra Nevada - Basin and Range boundary — tephrochronologic and gravity constraints on the record in Neogene basin deposits, sponsored by the National Science Foundation 6/00-5/02 for $55,182 between 3 PIs.

Analysis of shallow site response to LARSE-2 blasts at precarious rock sites near the San Andreas fault, sponsored by the Southern California Earthquake Center 7/99-3/02 for $37,270 between 3 PIs.

Geophysical test of low-angle dip on the seismogenic Dixie Valley fault, Nevada, sponsored by the National Science Foundation 9/97-8/99 for $91,313 between 3 PIs.

Seismic hazards in the vicinity of Las Vegas and Reno, sponsored by the U.S. Geological Survey 4/99-3/01 for $100,000 between 4 PIs.

Reflectivity structure below San Fernando Valley from Northridge aftershock recordings, sponsored by the National Science Foundation 9/94-2/96 for $46,978.

Geophysical constraints on extensional models for the Death Valley region of California and Nevada, sponsored by the National Science Foundation 8/94-8/97 for $70,256.

Graduate Education

California Institute of Technology, Pasadena, California. Degrees: Ph.D. Geophysics, June, 1987; M.S. Geophysics, June, 1983.

Relevant Publications

J. N. Louie, 2001, Faster, better: shear-wave velocity to 100 meters depth from refraction microtremor arrays: Bull. Seismol. Soc. Amer., 91, no. 2 (April), 347-364.

R. E. Abbott and J. N. Louie, 2000, Depth to bedrock using gravimetry in the Reno and Carson City, Nevada area basins: Geophysics, 65, 340-350.

A. M. Asad, S. K. Pullammanappallil, A. Anooshehpoor, and J. N. Louie, 1999, Inversion of traveltime data for earthquake locations and three-dimensional velocity structure in the Eureka Valley area, eastern California: Bull. Seismol. Soc. Amer., 89, 796-810.

S. Ozalaybey, M. K. Savage, A. F. Sheehan, J. N. Louie, and J. N. Brune, 1997, Shear-wave velocity structure in the northern Basin and Range province from the combined analysis of receiver functions and surface waves: Bull. Seismol. Soc. Amer., 87, 183-199.

J. N. Louie, S. K. Pullammanappallil, and W. Honjas, 1997, Velocity models for the highly extended crust of Death Valley, California: Geophys. Res. Lett., 24, 735-738.

Other Important Publications

R. E. Abbott, J. N. Louie, S. J. Caskey, and S. Pullammanappallil, 2001, Geophysical confirmation of low-angle normal slip on the historically active Dixie Valley fault, Nevada: Jour. Geophys. Res., 106, 4169-4181.

Z. Kanbur, J. N. Louie, S. Chavez-Perez, G. Plank, and D. Morey, 2000, Seismic reflection study of Upheaval Dome, Canyonlands National Park, Utah: Jour. Geophys. Res. (Planets), 105, 9489-9505.

S. Chavez-Perez and J. N. Louie, 1998, Crustal imaging in southern California using earthquake sequences: Tectonophysics, 286 (March 15), 223-236.

S. Chavez-Perez, J. N. Louie, and S. K. Pullammanappallil, 1998, Seismic depth imaging of normal faulting in the southern Death Valley basin: Geophysics, 63, 223-230.

S. K. Pullammanappallil and J. N. Louie, 1994, A generalized simulated-annealing optimization for inversion of first-arrival times: Bull. Seismol. Soc. Amer., 84, 1397-1409.

Recent Collaborators

Tomotaka Iwata, Kojiro Irikura, Ruey-Chuan Shih, John Taber, Stephen Bannister, Stuart Henrys, Roger Morrison, Lauren Wright, John Anderson, James Brune, Steve Wesnousky, Yuehua Zeng.

Thesis Advisor: Robert W. Clayton.

Graduate Students Advised

Jizeng Qin (M.S. 1989), Michael Matthewson, Raymond Laird, Satish K. Pullammanappallil (Ph.D. 1994), Deborah Dann, Abu Asad (Ph.D. 1998), William Honjas (M.S. 1993), Serdar Ozalaybey (Ph.D. 1996), Sergio Chavez-Perez (Ph.D. 1997), Ken Mela (M.S. 1997), Zakir Kanbur (M.S. 1997), Li Li, Robert E. Abbott (Ph.D. 2001), Matthew Clark, James Scott.

Current External Support - John N. Louie

National Science Foundation/Tectonics: Evolution of the Sierra Nevada - Basin and Range Boundary - Tephrochronologic and Gravity Constraints on the Record in Neogene Basin Deposits, $55,182, 6/1/2000 - 5/30/2002, Cashman, Louie (0.25 summer month), Trexler.

National Science Foundation/SCEC: Site Response Investigations at Critical Precarious Rocks Near the San Andreas Fault, $20,000, 4/01/2001 - 3/31/2002, Louie (0.5 summer month), Anderson, Brune, Anooshehpoor.

Dept. of Energy/Great Basin Center for Geothermal Energy: Assembly of a crustal seismic velocity database for the western Great Basin, $144,584, 4/1/2002 - 3/31/2003, Louie (1.0 summer month).

John G. Anderson

Seismological Laboratory, MS 174, University of Nevada, Reno, Nevada 89557

Phone: (702) 784 4265 Fax: (702) 784 1833 Email: jga@seismo.unr.edu

Education

Ph.D. Geophysics, 1976 Columbia University, New York City, New York

B. S. Physics, 1970 Michigan State University, East Lansing, Michigan

Diploma 1966 LaSalle High School, Niagara Falls, New York

Professional Experience

University of Nevada, Reno - Mackay School of Mines

Department of Geological Sciences

Professor of Geophysics: July 1992   present

Associate Professor of Geophysics: Sept. 1988   June 1992

Seismological Laboratory

Director, Feb. 1998 - present

Associate Director: Sept. 1989 – Feb. 1998

Acting Director: June 1994   Dec. 1995

University of California, San Diego

Institute of Geophysics and Planetary Physics

Associate Research Geophysicist and Lecturer: July 1984 to 30 June 1990

Assistant Research Geophysicist: August 1980 to 1984

Department of Applied Mechanics and Engineering Sciences

Associate Research Engineer: July 1984 to 30 June 1988

Assistant Research Engineer: August 1980 to 1984

University of Southern California, Los Angeles

Senior Research Associate: Oct. 1978 to 1980

Research Associate: October 1976 to 1978

California Institute of Technology, Pasadena, California

Research Fellow: November 1975 to 1976.

Lamont Doherty Geological Observatory of Columbia University, Palisades, N. Y.

Research Assistant: July 1970 to 1975.

Other Experience

Nevada Seismic Safety Council

Chairman, November 1992   November, 1997

Member, May 1992   present

Bulletin of the Seismological Society of America

Associate Editor, Sept 1992   1994

National Academy of Sciences

Committee on Seismic Base Isolation 1989 1993

Committee on Probabilistic Seismic Hazard Analysis 1984 1988

Major Research Interests

Engineering seismology: all aspects , including applications of geological and seismological information to estimate seismicity and seismic hazards; recording strong ground motions; understanding the physics of near-source ground motions; applications to engineering problems.

Selected Papers

Anderson, J. G. (1979) Estimating the seismicity from geological structure for seismic risk studies: Bull. Seism. Soc. Am. 69, 135-158.

Anderson, J. G. and S. Hough (1984). A Model for the shape of the Fourier amplitude spectrum of acceleration at high frequencies: Bull. Seism. Soc. Am. 74, 1969-1994.

Anderson, J. G., P. Bodin, J. Brune, J. Prince, S. Singh, R. Quaas, M. Onate, and E. Mena, (1986). Strong ground motion and source mechanism of the Mexico earthquake of Sept. 19, 1985, Science 233, 1043-1049.

Anderson, J. G. (1991). Strong Motion Seismology, Reviews of Geophysics, Seismology Supplement, U. S. National Report to the International Union of Geology and Geophysics 1987-1990, 700-720.

Yu, G., J. G. Anderson and R. Siddharthan (1993). On the characteristics of nonlinear soil response, Bull. Seism. Soc. Am. 83, 218-244.

Zeng, Y., J. G. Anderson and G. Yu (1994). A composite source model for computing realistic synthetic strong ground motions, Geophysical Research Letters 21, 725-728.

Anderson, J. G. and G. Yu (1996). Predictability of strong motions from the Northridge, California, earthquake, BSSA 86, S100-S114.

Anderson, J. G., S. G. Wesnousky, and M. W. Stirling (1996). Earthquake size as a function of fault slip rate, Bull. Seism. Soc. Am. 86, 683-690.

Anderson, J. G. (1997). Benefits of scenario ground motion maps, Engineering Geology 48, 43-57.

Anderson, J. G. (1997). Seismic energy and stress drop parameters for a composite source model, Bulletin of the Seismological Society of America 87, 85-96.

Anderson, J. G. and J. N. Brune (1999). Methodology for using precarious rocks in Nevada to test seismic hazard models, Bull. Seism. Soc. Am 89, 456-467.

Anderson, J. G. and J. N. Brune (1999). Probabilistic seismic hazard analysis without the ergodic assumption, Seismological Research Letters 70, 19-28.