David J Wald
Dr. Wald is a Seismologist with the USGS in Golden. He is involved in research, development & operations of several real-time earthquake information systems at the USGS National Earthquake Information Center. He developed and manages “ShakeMap”, “Did You Feel it?”, & is responsible for developing other systems for post-earthquake response & pre-earthquake mitigation, including ShakeCas
Wald's scientific interests include the characterization of rupture processes from complex recent and historic earthquakes using combined geodetic, teleseismic, and strong motion data; waveform modelling and inversion; analysis of ground motion hazards and site effects; earthquake source physics; and modelling earthquake-induced landslides, liquefaction, and losses, macroseismic intensity, building damage, financial and human impact, rapid damage and impact assessment, earthquake scenario development and mitigation planning and drills, and communication with the media, public, and emergency managers.
Previously at Caltech, and now at the Colorado School of Mines, Wald has advised dozens of post-doctoral, graduate, and undergraduate student research projects. Wald directly supervises 10 PhD level scientists and 5 five BS and MS level support staff, and supervises several students. Wald serves on several PhD committees at this time. This research has resulted in more than 450 professional publications that David has authored or co-authored, including journal papers, USGS publication series, conference papers, and published abstracts.
Education:
Post-doctoral Fellow, Geophysics, National Research Council, USGS, Pasadena, 1995
Ph.D., Geophysics, California Institute of Technology, Pasadena, CA, 1993
M.S., Geophysics, University of Arizona, Tucson, AZ, 1986
B.S., Geology & Physics, St. Lawrence University, Canton, NY, 1984
Science and Products
Intensity distribution and isoseismal maps for the Nisqually, Washington, earthquake of 28 February 2001
Instrumental intensity distribution for the Hector Mine, California, and the Chi-Chi, Taiwan, earthquakes: Comparison of two methods
Did you feel it? Community-made earthquake shaking maps
Resolution analysis of finite fault source inversion using one- and three-dimensional Green's functions 1. Strong motions
Southern California seismic network: Caltech/USGS element of TriNet 1997-2001
Slip distribution and tectonic implication of the 1999 Chi-Chi, Taiwan, earthquake
Resolution analysis of finite fault source inversion using one- and three-dimensional Green's functions 2. Combining seismic and geodetic data
"ShakeMaps" - instant maps of earthquake shaking
Preliminary report on the 16 October 1999 M 7.1 Hector mine, California, earthquake
TriNet "ShakeMaps": Rapid generation of peak ground motion and intensity maps for earthquakes in southern California
Characterizing crustal earthquake slip models for the prediction of strong ground motion
Relationships between peak ground acceleration, peak ground velocity, and Modified Mercalli Intensity in California
Non-USGS Publications**
**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.
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Filter Total Items: 157
Intensity distribution and isoseismal maps for the Nisqually, Washington, earthquake of 28 February 2001
We present isoseismal maps, macroseismic intensities, and community summaries of damage for the MW=6.8 Nisqually, Washington, earthquake of 28 February, 2001. For many communities, two types of macroseismic intensity are assigned, the traditional U.S. Geological Survey Modified Mercalli Intensities (USGS MMI) and a type of intensity newly introduced with this paper, the USGS Reviewed CommunAuthorsJames W. Dewey, Margaret G. Hopper, David J. Wald, Vincent Quitoriano, Elizabeth R. AdamsInstrumental intensity distribution for the Hector Mine, California, and the Chi-Chi, Taiwan, earthquakes: Comparison of two methods
We compare two methods of seismic-intensity estimation from ground-motion records for the two recent strong earthquakes: the 1999 (M 7.1) Hector Mine, California, and the 1999 (M 7.6) Chi-Chi, Taiwan. The first technique utilizes the peak ground acceleration (PGA) and velocity (PGV), and it is used for rapid generation of the instrumental intensity map in California. The other method is based on tAuthorsV. Sokolov, D. J. WaldDid you feel it? Community-made earthquake shaking maps
Since the early 1990's, the magnitude and location of an earthquake have been available within minutes on the Internet. Now, as a result of work by the U.S. Geological Survey (USGS) and with the cooperation of various regional seismic networks, people who experience an earthquake can go online and share information about its effects to help create a map of shaking intensities and damage. Such 'ComAuthorsD. J. Wald, L. A. Wald, J. W. Dewey, Vince Quitoriano, Elisabeth AdamsResolution analysis of finite fault source inversion using one- and three-dimensional Green's functions 1. Strong motions
We develop a methodology to perform finite fault source inversions from strong motion data using Green's functions (GFs) calculated for a three-dimensional (3-D) velocity structure. The 3-D GFs are calculated numerically by inserting body forces at each of the strong motion sites and then recording the resulting strains along the target fault surface. Using reciprocity, these GFs can be recombinedAuthorsR.W. Graves, D. J. WaldSouthern California seismic network: Caltech/USGS element of TriNet 1997-2001
No abstract available.AuthorsE. Hauksson, P. Small, K. Hafner, R. Busby, R. Clayton, J. Goltz, T. Heaton, K. Hutton, H. Kanamori, J. Polet, D. Given, L.M. Jones, D. WaldSlip distribution and tectonic implication of the 1999 Chi-Chi, Taiwan, earthquake
We report on the fault complexity of the large (Mw = 7.6) Chi-Chi earthquake obtained by inverting densely and well-distributed static measurements consisting of 119 GPS and 23 doubly integrated strong motion records. We show that the slip of the Chi-Chi earthquake was concentrated on the surface of a "wedge shaped" block. The inferred geometric complexity explains the difference between the strikAuthorsC. Ji, D.V. Helmberger, T.-R.A. Song, K.-F. Ma, D. J. WaldResolution analysis of finite fault source inversion using one- and three-dimensional Green's functions 2. Combining seismic and geodetic data
Using numerical tests for a prescribed heterogeneous earthquake slip distribution, we examine the importance of accurate Green's functions (GF) for finite fault source inversions which rely on coseismic GPS displacements and leveling line uplift alone and in combination with near-source strong ground motions. The static displacements, while sensitive to the three-dimensional (3-D) structure, are lAuthorsD. J. Wald, R.W. Graves"ShakeMaps" - instant maps of earthquake shaking
No abstract available.AuthorsDavid Wald, Lisa Wald, Jim Goltz, Bruce Worden, Craig ScrivnerPreliminary report on the 16 October 1999 M 7.1 Hector mine, California, earthquake
The Mw 7.1 Hector Mine, California, earthquake occurred at 9:46 GMT on 16 October 1999. The event caused minimal damage because it was located in a remote, sparsely populated part of the Mojave Desert, approximately 47 miles east-southeast of Barstow, with epicentral coordinates 34.59°N 116.27°W and a hypocentral depth of 5 ± 3 km. Twelve foreshocks, M 1.9-3.8, preceded the mainshock during the prAuthorsJ. Behr, B. Bryant, D. Given, K. Gross, K. Hafner, J. Hardebeck, E. Hauksson, T. Heaton, S. Hough, K. Hudnut, K. Hutton, L. Jones, H. Kanamori, K. Kendrick, N. King, P. Maechling, A. Meltzner, D. Ponti, Thomas Rockwell, A. Shakal, M. Simons, K. Stark, D. Wald, L. Wald, L. ZhuTriNet "ShakeMaps": Rapid generation of peak ground motion and intensity maps for earthquakes in southern California
Rapid (3-5 minutes) generation of maps of instrumental ground-motion and shaking intensity is accomplished through advances in real-time seismographic data acquisition combined with newly developed relationships between recorded ground-motion parameters and expected shaking intensity values. Estimation of shaking over the entire regional extent of southern California is obtained by the spatial intAuthorsDavid J. Wald, Vince Quitoriano, Thomas H. Heaton, Hiroo Kanamori, Craig Scrivner, C. Bruce WordenCharacterizing crustal earthquake slip models for the prediction of strong ground motion
[No abstract available]AuthorsP. Somerville, K. Irikura, R. Graves, S. Sawada, D. Wald, N. Abrahamson, Y. Iwasaki, T. Kagawa, N. Smith, A. KowadaRelationships between peak ground acceleration, peak ground velocity, and Modified Mercalli Intensity in California
We have developed regression relationships between Modified Mercalli Intensity (Imm) and peak ground acceleration (PGA) and velocity (PGV) by comparing horizontal peak ground motions to observed intensities for eight significant California earthquakes. For the limited range of Modified Mercalli intensities (Imm), we find that for peak acceleration with V ≤ Imm ≤ VIII, Imm = 3.66 log(PGA) − 1.66, aAuthorsDavid J. Wald, Vincent Quitoriano, Thomas H. Heaton, Hiroo KanamoriNon-USGS Publications**
References in Google Scholar**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.
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