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 ShakeCast.
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
Honors and Awards
2025 - Alfred E. Alquist Special Recognition Medal of Earthquake Engineering Research Institute
2023 - Presidential Rank Award
2023 - USGS Shoemaker Lifetime Achievement Award in Communications
2023 - American Geophysical Union Fellow
2018—2023 - Editor-in-Chief, Earthquake Spectra
2021 - Joyner Lectureship, Seismological Society of America and the Earthquake Engineering Research Institute
2015—2017 - Board of Directors, Earthquake Engineering Research Institute
2016 - Meritorious Service Award (MSA), Department of the Interior
2015 - Distinguished Lecturer, Earthquake Engineering Research Institute
2015—2017 - Board of Directors, Earthquake Engineering Research Institute
2009—2011 - Board of Directors, Seismological Society of America
2010 - Superior Service Award (SSA), Department of the Interior
2009 - Frank Press Public Service Award of the Seismological Society of America
2004 - Seismological Society of America’s Distinguished Lecturer
2003 - U.S.G.S. Shoemaker Award. Excellence in Communications
Science and Products
Filter Total Items: 163
Aftershocks and triggered events of the Great 1906 California earthquake Aftershocks and triggered events of the Great 1906 California earthquake
The San Andreas fault is the longest fault in California and one of the longest strike-slip faults in the world, yet little is known about the aftershocks following the most recent great event on the San Andreas, the Mw 7.8 San Francisco earthquake on 18 April 1906. We conducted a study to locate and to estimate magnitudes for the largest aftershocks and triggered events of this...
Authors
A.J. Meltzner, D.J. Wald
Slip history and dynamic implications of the 1999 Chi-Chi, Taiwan, earthquake Slip history and dynamic implications of the 1999 Chi-Chi, Taiwan, earthquake
[1] We investigate the rupture process of the 1999 Chi‐Chi, Taiwan, earthquake using extensive near‐source observations, including three‐component velocity waveforms at 36 strong motion stations and 119 GPS measurements. A three‐plane fault geometry derived from our previous inversion using only static data [Ji et al., 2001] is applied. The slip amplitude, rake angle, rupture initiation...
Authors
Ji Chen, Donald V. Helmberger, David J. Wald, Kuo-Fong Ma
Development of a ShakeMap-based, earthquake response system within caltrans Development of a ShakeMap-based, earthquake response system within caltrans
The development of a shakemap-based earthquake response system within Caltrans is discussed. Caltrans is test deploying a simplified protocol for its direct use for post-earthquake prioritization of bridge inspection. The process involves employing a GIS spatial analysis to identify the bridges that were most strongly shaken.
Authors
D.J. Wald, P.A. Naecker, C. Roblee, Loren Turner
Bayesian Estimations of Peak Ground Acceleration and 5% Damped Spectral Acceleration from Modified Mercalli Intensity Data Bayesian Estimations of Peak Ground Acceleration and 5% Damped Spectral Acceleration from Modified Mercalli Intensity Data
We describe a new probabilistic method that uses observations of modified Mercalli intensity (MMI) from past earthquakes to make quantitative estimates of ground shaking parameters (i.e., peak ground acceleration, peak ground velocity, 5% damped spectral acceleration values, etc.). The method uses a Bayesian approach to make quantitative estimates of the probabilities of different levels...
Authors
J.E. Ebel, D.J. Wald
Felt reports and intensity assignments for aftershocks and triggered events of the great 1906 California earthquake Felt reports and intensity assignments for aftershocks and triggered events of the great 1906 California earthquake
The San Andreas fault is the longest fault in California and one of the longest strikeslip faults in the world, yet little is known about the aftershocks following the most recent great event on the San Andreas, the M 7.8 San Francisco earthquake, on 18 April 1906. This open-file report is a compilation of first-hand accounts (felt reports) describing aftershocks and triggered events of...
Authors
Aron J. Meltzner, David J. Wald
Intensity distribution and isoseismal maps for the Nisqually, Washington, earthquake of 28 February 2001 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...
Authors
James W. Dewey, Margaret G. Hopper, David J. Wald, Vincent Quitoriano, Elizabeth R. Adams
Instrumental intensity distribution for the Hector Mine, California, and the Chi-Chi, Taiwan, earthquakes: Comparison of two methods Instrumental 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...
Authors
V. Sokolov, D.J. Wald
Did you feel it? Community-made earthquake shaking maps Did 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...
Authors
D.J. Wald, L. A. Wald, J. W. Dewey, Vince Quitoriano, Elisabeth Adams
Resolution analysis of finite fault source inversion using one- and three-dimensional Green's functions 1. Strong motions Resolution 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...
Authors
R.W. Graves, D.J. Wald
Resolution analysis of finite fault source inversion using one- and three-dimensional Green's functions 2. Combining seismic and geodetic data Resolution 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)...
Authors
D.J. Wald, R.W. Graves
Southern California seismic network: Caltech/USGS element of TriNet 1997-2001 Southern California seismic network: Caltech/USGS element of TriNet 1997-2001
No abstract available.
Authors
E. 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. Wald
Slip distribution and tectonic implication of the 1999 Chi-Chi, Taiwan, earthquake Slip 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...
Authors
C. Ji, D.V. Helmberger, T.-R.A. Song, K.-F. Ma, D.J. Wald
Non-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.
Science and Products
Filter Total Items: 163
Aftershocks and triggered events of the Great 1906 California earthquake Aftershocks and triggered events of the Great 1906 California earthquake
The San Andreas fault is the longest fault in California and one of the longest strike-slip faults in the world, yet little is known about the aftershocks following the most recent great event on the San Andreas, the Mw 7.8 San Francisco earthquake on 18 April 1906. We conducted a study to locate and to estimate magnitudes for the largest aftershocks and triggered events of this...
Authors
A.J. Meltzner, D.J. Wald
Slip history and dynamic implications of the 1999 Chi-Chi, Taiwan, earthquake Slip history and dynamic implications of the 1999 Chi-Chi, Taiwan, earthquake
[1] We investigate the rupture process of the 1999 Chi‐Chi, Taiwan, earthquake using extensive near‐source observations, including three‐component velocity waveforms at 36 strong motion stations and 119 GPS measurements. A three‐plane fault geometry derived from our previous inversion using only static data [Ji et al., 2001] is applied. The slip amplitude, rake angle, rupture initiation...
Authors
Ji Chen, Donald V. Helmberger, David J. Wald, Kuo-Fong Ma
Development of a ShakeMap-based, earthquake response system within caltrans Development of a ShakeMap-based, earthquake response system within caltrans
The development of a shakemap-based earthquake response system within Caltrans is discussed. Caltrans is test deploying a simplified protocol for its direct use for post-earthquake prioritization of bridge inspection. The process involves employing a GIS spatial analysis to identify the bridges that were most strongly shaken.
Authors
D.J. Wald, P.A. Naecker, C. Roblee, Loren Turner
Bayesian Estimations of Peak Ground Acceleration and 5% Damped Spectral Acceleration from Modified Mercalli Intensity Data Bayesian Estimations of Peak Ground Acceleration and 5% Damped Spectral Acceleration from Modified Mercalli Intensity Data
We describe a new probabilistic method that uses observations of modified Mercalli intensity (MMI) from past earthquakes to make quantitative estimates of ground shaking parameters (i.e., peak ground acceleration, peak ground velocity, 5% damped spectral acceleration values, etc.). The method uses a Bayesian approach to make quantitative estimates of the probabilities of different levels...
Authors
J.E. Ebel, D.J. Wald
Felt reports and intensity assignments for aftershocks and triggered events of the great 1906 California earthquake Felt reports and intensity assignments for aftershocks and triggered events of the great 1906 California earthquake
The San Andreas fault is the longest fault in California and one of the longest strikeslip faults in the world, yet little is known about the aftershocks following the most recent great event on the San Andreas, the M 7.8 San Francisco earthquake, on 18 April 1906. This open-file report is a compilation of first-hand accounts (felt reports) describing aftershocks and triggered events of...
Authors
Aron J. Meltzner, David J. Wald
Intensity distribution and isoseismal maps for the Nisqually, Washington, earthquake of 28 February 2001 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...
Authors
James W. Dewey, Margaret G. Hopper, David J. Wald, Vincent Quitoriano, Elizabeth R. Adams
Instrumental intensity distribution for the Hector Mine, California, and the Chi-Chi, Taiwan, earthquakes: Comparison of two methods Instrumental 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...
Authors
V. Sokolov, D.J. Wald
Did you feel it? Community-made earthquake shaking maps Did 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...
Authors
D.J. Wald, L. A. Wald, J. W. Dewey, Vince Quitoriano, Elisabeth Adams
Resolution analysis of finite fault source inversion using one- and three-dimensional Green's functions 1. Strong motions Resolution 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...
Authors
R.W. Graves, D.J. Wald
Resolution analysis of finite fault source inversion using one- and three-dimensional Green's functions 2. Combining seismic and geodetic data Resolution 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)...
Authors
D.J. Wald, R.W. Graves
Southern California seismic network: Caltech/USGS element of TriNet 1997-2001 Southern California seismic network: Caltech/USGS element of TriNet 1997-2001
No abstract available.
Authors
E. 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. Wald
Slip distribution and tectonic implication of the 1999 Chi-Chi, Taiwan, earthquake Slip 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...
Authors
C. Ji, D.V. Helmberger, T.-R.A. Song, K.-F. Ma, D.J. Wald
Non-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.