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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

 

 

 

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A map of the magnitude 5.4 Earthquake Felt in Puerto Rico showing it hit about six miles offshore on the south side of island

Developing and Implementing an International Macroseismic Scale (IMS) for Earthquake Engineering, Earthquake Science, and Rapid Damage Assessment

The USGS “Did You Feel It” (DYFI) is an extremely popular way for members of the public to contribute to earthquake science and earthquake response. DYFI has been in operation for nearly two decades (1999-2019) in the U.S., and for nearly 15 years globally. During that period the amount of data collected is astounding: Over 5 million individual DYFI intensity reports—spanning all magnitude and dis...
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John Wesley Powell Center for Analysis and Synthesis
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Developing and Implementing an International Macroseismic Scale (IMS) for Earthquake Engineering, Earthquake Science, and Rapid Damage Assessment

The USGS “Did You Feel It” (DYFI) is an extremely popular way for members of the public to contribute to earthquake science and earthquake response. DYFI has been in operation for nearly two decades (1999-2019) in the U.S., and for nearly 15 years globally. During that period the amount of data collected is astounding: Over 5 million individual DYFI intensity reports—spanning all magnitude and dis...
Learn More
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map of Los Angeles area with different gradational colors

The Blind Zone of Earthquake Early Warning

Release Date: MAY 29, 2020Residents in California, Oregon, and Washington have been told that earthquake early warning (EEW) is at their doorstep and will alert them to the shaking from an earthquake before it arrives. Some media reports have said there will be “up to a minute of warning”. The problem is, for onshore earthquakes these claims are exaggerated, and under some conditions a warning is...
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Natural Hazards, Earthquake Hazards
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The Blind Zone of Earthquake Early Warning

Release Date: MAY 29, 2020Residents in California, Oregon, and Washington have been told that earthquake early warning (EEW) is at their doorstep and will alert them to the shaking from an earthquake before it arrives. Some media reports have said there will be “up to a minute of warning”. The problem is, for onshore earthquakes these claims are exaggerated, and under some conditions a warning is...
Learn More
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World map showing the global distribution of earthquakes in gray scale.

Future Opportunities in Regional and Global Seismic Network Monitoring and Science

The past decade has seen improvements in computational efficiency, seismic data coverage, and communication technology - driven by societal expectation for timely, accurate information. While aspects of earthquake research have taken advantage of this evolution, the adoption of improvements in earthquake monitoring has not been fully leveraged. In real-time monitoring, earthquakes are characterize
By
John Wesley Powell Center for Analysis and Synthesis
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Future Opportunities in Regional and Global Seismic Network Monitoring and Science

The past decade has seen improvements in computational efficiency, seismic data coverage, and communication technology - driven by societal expectation for timely, accurate information. While aspects of earthquake research have taken advantage of this evolution, the adoption of improvements in earthquake monitoring has not been fully leveraged. In real-time monitoring, earthquakes are characterize
Learn More
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USGS science for a changing world logo

Operational Earthquake Forecasting – Implementing a Real-Time System for California

It is well know that every earthquake can spawn others (e.g., as aftershocks), and that such triggered events can be large and damaging, as recently demonstrated by L’Aquila, Italy and Christchurch, New Zealand earthquakes. In spite of being an explicit USGS strategic-action priority (http://pubs.usgs.gov/of/2012/1088; page 32), the USGS currently lacks an automated system with which to forecast s...
By
John Wesley Powell Center for Analysis and Synthesis
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Operational Earthquake Forecasting – Implementing a Real-Time System for California

It is well know that every earthquake can spawn others (e.g., as aftershocks), and that such triggered events can be large and damaging, as recently demonstrated by L’Aquila, Italy and Christchurch, New Zealand earthquakes. In spite of being an explicit USGS strategic-action priority (http://pubs.usgs.gov/of/2012/1088; page 32), the USGS currently lacks an automated system with which to forecast s...
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A Global Hybrid Vs30 Map with a Topographic-Slope-Based Default and Regional Map Insets

Time-averaged shear wave velocity over the upper 30 meters of the earth's surface (Vs30) is a key parameter for estimating ground motion amplification as both a predictive and diagnostic tool for earthquake hazards. A first-order approximation of Vs30 is commonly obtained via a topographic slope-based or terrain proxy due to the widely available nature of digital elevation models. However, better-
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Natural Hazards, Earthquake Hazards, Geologic Hazards Science Center

An Open Repository of Earthquake-Triggered Ground-Failure Inventories

Earthquake-triggered ground-failure, such as landsliding and liquefaction, can contribute significantly to losses, but our current ability to accurately include them in earthquake hazard analyses is limited. The development of robust and transportable models requires access to numerous inventories of ground failure triggered by earthquakes that span a broad range of terrains, shaking characteristi
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Earthquake Hazards
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Comment on “Which earthquake accounts matter” by Susan E. Hough and Stacey S. Martin

In their analysis of the U.S. Geological Survey’s (USGS) “Did You Feel It?” (DYFI) data Hough and Martin (2021) claim, among other assertions, that the following:Socioeconomic and geopolitical factors can introduce biases in the USGS’ characterization of earthquakes and their effects, especially if online data collection systems are not designed to be broadly accessible;These biases can, in turn,
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Natural Hazards, Geologic Hazards Science Center

Evaluation of intensity prediction equations (IPEs) for small-magnitude earthquakes

This study assesses existing intensity prediction equations (IPEs) for small unspecified magnitude (M ≤3.5) earthquakes at short hypocentral distances (⁠Dh⁠) and explores such earthquakes’ contribution to the felt shaking hazard. In particular, we consider IPEs by Atkinson and Wald (2007) and Atkinson et al. (2014), and evaluate their performance based on “Did You Feel It” (DYFI) reports and recor
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Natural Hazards, Geologic Hazards Science Center

An efficient Bayesian framework for updating PAGER loss estimates

We introduce a Bayesian framework for incorporating time-varying noisy reported data on damage and loss information to update near real-time loss estimates/alerts for the U.S. Geological Survey’s Prompt Assessment of Global Earthquakes for Response (PAGER) system. Initial loss estimation by PAGER immediately following an earthquake includes several uncertainties. Historically, the PAGER’s alerting
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Natural Hazards, Geologic Hazards Science Center

The US Geological Survey ground failure product: Near-real-time estimates of earthquake-triggered landslides and liquefaction

Since late 2018, the US Geological Survey (USGS) ground failure (GF) earthquake product has provided publicly available spatial estimates of earthquake-triggered landslide and liquefaction hazards, along with the qualitative hazard and population exposure-based alerts for M > 6 earthquakes worldwide and in near real time (within ∼30 min). Earthquake losses are oftentimes greatly aggravated by the
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Natural Hazards, Geologic Hazards Science Center

ShakeMap operations, policies, and procedures

The US Geological Survey’s ShakeMap is used domestically and globally for post-earthquake emergency management and response, engineering analyses, financial instruments, and other decision-making activities. Recent developments in the insurance, reinsurance, and catastrophe bond sectors link payouts of potentially hundreds of millions of dollars to ShakeMap products. Similarly, building codes, pos
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Natural Hazards, Earthquake Hazards, Geologic Hazards Science Center

Amateur radio operators help fill earthquake donut holes

If you’ve ever seen tall antennas rising from everyday residences in your community and wondered what they are for, it could be that those homes belong to ham radio enthusiasts who enjoy communicating with each other over the airwaves. In addition to having fun with their radios and finding camaraderie, many ham radio operators are also prepared to help neighbors and authorities communicate during
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Natural Hazards, Earthquake Hazards, Geologic Hazards Science Center

Quantifying nuisance ground motion thresholds for induced earthquakes

Hazards from induced earthquakes are a growing concern with a need for effective management. One aspect of that concern is the “nuisance” from unexpected ground motions, which have the potential to cause public alarm and discontent. In this article, we borrow earthquake engineering concepts to quantify the chance of building damage states and adapt them to quantify felt thresholds for induced eart
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Natural Hazards, Earthquake Hazards, Geologic Hazards Science Center

Assessing the long-term earthquake risk for the US National Bridge Inventory (NBI)

We estimate annualized earthquake loss associated with over 600,000 bridges located throughout the contiguous United States. Each year, the Federal Highway Administration, in partnership with State Departments of Transportation, undertake a massive exercise to update the National Bridge Inventory (NBI) by combining data from states, federal agencies, local jurisdictions, and tribal governments. Th
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Natural Hazards, Geologic Hazards Science Center

Financial risk innovation: Development of earthquake parametric triggers for contingent credit instruments

The Inter-American Development Bank (IDB) has developed financial risk management strategies for natural disasters focusing primarily on the emergency phase of the catastrophes where financial support is more cost-efficient and certainly most needed. The main IDB financial instrument to provide liquidity in the aftermath of catastrophic events is the Contingent Credit Facility (CCF). The CCF is a
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Natural Hazards, Earthquake Hazards, Geologic Hazards Science Center

Human behavioral response in the Ridgecrest earthquakes: Assessing immediate actions based on data from “Did You Feel It?”

Human behavioral response to earthquake ground motion has long been a subject of multidisciplinary interest and research. In most versions of seismic intensity scales, human perceptions and behavior are one component of the assignment of intensity. Public health research has shown that actions taken during earthquakes have a significant impact on the incidence of injury or the maintenance of safet
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Natural Hazards, Earthquake Hazards, Geologic Hazards Science Center

A global hybrid VS30 map with a topographic slope–based default and regional map insets

Time-averaged shear wave velocity over the upper 30 m of the earth’s surface (VS30) is a key parameter for estimating ground motion amplification as both a predictive and a diagnostic tool for earthquake hazards. The first-order approximation of VS30 is commonly obtained through a topographic slope–based or terrain proxy due to the widely available nature of digital elevation models. However, bett
By
Natural Hazards, Geologic Hazards Science Center

Practical limitations of Earthquake Early Warning

Earthquake Early Earning (EEW) entails detection of initial earthquake shaking and rapid estimation and notification to users prior to imminent, stronger shaking. EEW is coming to the U.S. West Coast. But what are the technical and social challenges to delivering actionable information on earthquake shaking before it arrives? Although there will be tangible benefits, there are also limitations. Ba
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Natural Hazards, Earthquake Hazards, Geologic Hazards Science Center

Pre-USGS Publications

References in Google Scholar

ShakeCast

An application for automating ShakeMap delivery to critical users and for facilitating notification of shaking levels at user-selected facilities.

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Earthquake Hazards
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The Blind Zone of Earthquake Early Warning

One USGS scientist has sorted through the challenges, the claims, and the data to determine what the possibilities and limitations really are for EEW...

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