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 and PAGER.
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.
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
Estimating structural collapse fragility of generic building typologies using expert judgment
The structured expert elicitation process proposed by Cooke (1991), hereafter referred to as Cooke’s approach, is applied for the first time in the realm of structural collapse-fragility assessment for selected generic construction types. Cooke’s approach works on the principle of objective calibration scoring of judgments coupled with...Deodatis, George; Ellingwood, Bruce R.; Frangopol, Dan M.; Jaiswal, Kishor S.; Wald, D.J.; Perkins, D.; Aspinall, W.P.; Kiremidjian, Anne S.
Predicting the spatial extent of liquefaction from geospatial and earthquake specific parameters
The spatially extensive damage from the 2010-2011 Christchurch, New Zealand earthquake events are a reminder of the need for liquefaction hazard maps for anticipating damage from future earthquakes. Liquefaction hazard mapping as traditionally relied on detailed geologic mapping and expensive site studies. These traditional techniques are...Deodatis, George; Ellingwood, Bruce R.; Frangopol, Dan M.; Zhu, Jing; Baise, Laurie G.; Thompson, Eric M.; Wald, David J.; Knudsen, Keith L.
Estimating economic losses from earthquakes using an empirical approach
We extended the U.S. Geological Survey's Prompt Assessment of Global Earthquakes for Response (PAGER) empirical fatality estimation methodology proposed by Jaiswal et al. (2009) to rapidly estimate economic losses after significant earthquakes worldwide. The requisite model inputs are shaking intensity estimates made by the ShakeMap system, the...Jaiswal, Kishor; Wald, David J.
Strategies for rapid global earthquake impact estimation: the Prompt Assessment of Global Earthquakes for Response (PAGER) system
This chapter summarizes the state-of-the-art for rapid earthquake impact estimation. It details the needs and challenges associated with quick estimation of earthquake losses following global earthquakes, and provides a brief literature review of various approaches that have been used in the past. With this background, the chapter introduces the...Jaiswal, Kishor; Wald, D.J.
Developing ShakeCast statistical fragility analysis framework for rapid post-earthquake assessment
When an earthquake occurs, the U. S. Geological Survey (USGS) ShakeMap estimates the extent of potentially damaging shaking and provides overall information regarding the affected areas. The USGS ShakeCast system is a freely-available, post-earthquake situational awareness application that automatically retrieves earthquake shaking data from...Lin, K.-W.; Wald, D.J.
Developing Vs30 site-condition maps by combining observations with geologic and topographic constraints
Despite obvious limitations as a proxy for site amplification, the use of time-averaged shear-wave velocity over the top 30 m (VS30) remains widely practiced, most notably through its use as an explanatory variable in ground motion prediction equations (and thus hazard maps and ShakeMaps, among other applications). As such, we are developing an...Thompson, E.M.; Wald, D.J.
Impact-based earthquake alerts with the U.S. Geological Survey's PAGER system: what's next?
In September 2010, the USGS began publicly releasing earthquake alerts for significant earthquakes around the globe based on estimates of potential casualties and economic losses with its Prompt Assessment of Global Earthquakes for Response (PAGER) system. These estimates significantly enhanced the utility of the USGS PAGER system which had been,...Wald, D.J.; Jaiswal, K.S.; Marano, K.D.; Garcia, D.; So, E.; Hearne, M.
Improving PAGER's real-time earthquake casualty and loss estimation toolkit: a challenge
We describe the on-going developments of PAGER’s loss estimation models, and discuss value-added web content that can be generated related to exposure, damage and loss outputs for a variety of PAGER users. These developments include identifying vulnerable building types in any given area, estimating earthquake-induced damage and loss statistics by...Jaiswal, K.S.; Wald, D.J.
ShakeMap Atlas 2.0: an improved suite of recent historical earthquake ShakeMaps for global hazard analyses and loss model calibration
We introduce the second version of the U.S. Geological Survey ShakeMap Atlas, which is an openly-available compilation of nearly 8,000 ShakeMaps of the most significant global earthquakes between 1973 and 2011. This revision of the Atlas includes: (1) a new version of the ShakeMap software that improves data usage and uncertainty estimations; (2)...Garcia, D.; Mah, R.T.; Johnson, K.L.; Hearne, M.G.; Marano, K.D.; Lin, K.-W.; Wald, D.J.
Use of expert judgment elicitation to estimate seismic vulnerability of selected building types
Pooling engineering input on earthquake building vulnerability through an expert judgment elicitation process requires careful deliberation. This article provides an overview of expert judgment procedures including the Delphi approach and the Cooke performance-based method to estimate the seismic vulnerability of a building category.Jaiswal, K.S.; Aspinall, W.; Perkins, D.; Wald, D.; Porter, K.A.
A global earthquake discrimination scheme to optimize ground-motion prediction equation selection
We present a new automatic earthquake discrimination procedure to determine in near-real time the tectonic regime and seismotectonic domain of an earthquake, its most likely source type, and the corresponding ground-motion prediction equation (GMPE) class to be used in the U.S. Geological Survey (USGS) Global ShakeMap system. This method makes use...Garcia, Daniel; Wald, David J.; Hearne, Michael
Probabilistic Relationships between Ground‐Motion Parameters and Modified Mercalli Intensity in California
We use a database of approximately 200,000 modified Mercalli intensity (MMI) observations of California earthquakes collected from USGS "Did You Feel It?" (DYFI) reports, along with a comparable number of peak ground-motion amplitudes from California seismic networks, to develop probabilistic relationships between MMI and peak ground velocity (PGV...Worden, C.B.; Wald, David J.; Rhoades, D.A.