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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...
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map of Los Angeles area with different gradational colors

The Blind Zone of Earthquake Early Warning

Release Date: MAY 29, 2020 Residents 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 Mission Area, Earthquake Hazards Program
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The Blind Zone of Earthquake Early Warning

Release Date: MAY 29, 2020 Residents 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...
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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 Mission Area, Earthquake Hazards Program, 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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Natural Hazards Mission Area, Earthquake Hazards Program, Landslide Hazards Program, Geologic Hazards Science Center

Shakemap earthquake scenario: Building Seismic Safety Council 2014 Event Set (BSSC2014)

This is a catalog of earthquake scenarios, represented as ShakeMaps. A ShakeMap is a USGS product that facilitates communication of earthquake effects by portraying a map of the severity of shaking. Maps of shaking severity are provided in terms of macroseismic intensity, peak ground acceleration, peak ground velocity, and spectral accelerations (at 0.3, 1.0 and 3 sec oscillator periods).
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Natural Hazards Mission Area, Earthquake Hazards Program, Geologic Hazards Science Center
Image: Damage from 2008 Great Sichuan Earthquake in China
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Filter Total Items: 149

DisasterNet: Causal Bayesian networks with normalizing flows for cascading hazards

Sudden-onset hazards like earthquakes often induce cascading secondary hazards (e.g., landslides, liquefaction, debris flows, etc.) and subsequent impacts (e.g., building and infrastructure damage) that cause catastrophic human and economic losses. Rapid and accurate estimates of these hazards and impacts are critical for timely and effective post-disaster responses. Emerging remote sensing techni
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Xuechun Li, Paula Madeline Burgi, Wei Ma, Haeyoung Noh, David J. Wald, Susu Xu
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Natural Hazards Mission Area, Geologic Hazards Science Center

Alerting the globe of consequential earthquakes

The primary ingredients on the hazard side of the equation include the rapid characterization of the earthquake source and quantifying the spatial distribution of the shaking, plus any secondary hazards an earthquake may have triggered. On the earthquake impact side, loss calculations require the aforementioned hazard assessments—and their uncertainties—as input, plus the quantification of the exp
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David J. Wald
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Natural Hazards Mission Area, Geologic Hazards Science Center

Rapid characterization of the February 2023 Kahramanmaraş, Turkey, earthquake sequence

The 6 February 2023 Mw 7.8 Pazarcık and subsequent Mw  7.5 Elbistan earthquakes generated strong ground shaking that resulted in catastrophic human and economic loss across south‐central Türkiye and northwest Syria. The rapid characterization of the earthquakes, including their location, size, fault geometries, and slip kinematics, is critical to estimate the impact of significant seismic events.
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Dara Elyse Goldberg, Tuncay Taymaz, Nadine G. Reitman, Alexandra Elise Hatem, Seda Yolsal-Çevikbilen, William D. Barnhart, Tahir Serkan Irmak, David J. Wald, Taylan Öcalan, William L. Yeck, Berkan Özkan, Jessica Ann Thompson Jobe, David R. Shelly, Eric M. Thompson, Christopher DuRoss, Paul S. Earle, Richard W. Briggs, Harley M. Benz, Ceyhun Erman, Ali Hasan Doğan, Cemali Altuntaş
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Natural Hazards Mission Area, Earthquake Hazards Program, Geologic Hazards Science Center

Seismic multi-hazard and impact estimation via causal inference from satellite imagery

Rapid post-earthquake reconnaissance is important for emergency responses and rehabilitation by providing accurate and timely information about secondary hazards and impacts, including landslide, liquefaction, and building damage. Despite the extensive collection of geospatial data and satellite images, existing physics-based and data-driven methods suffer from low estimation performance due to th
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Susu Xu, Joshua Dimasaka, David J. Wald, Hae Young Noh
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Natural Hazards Mission Area, Geologic Hazards Science Center

Assessing direct and indirect long-term economic impacts from earthquakes to the U.S. National Bridge Inventory

Using the 2018 National Seismic Hazard Model and the 2018 National Bridge Inventory, an annualized earthquake loss (AEL) study was conducted for approximately 610,000 bridges in the conterminous United States, quantifying both direct and indirect economic losses. The typical AEL framework has been augmented with new replacement unit cost data and bridge-specific parameters for modifying default fr
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Kishor Jaiswal, N. Simon Kwong, Doug Bausch, David J. Wald, Kuo-wan Lin, Sharon Yen, Jerry Shen, Jeffrey Ger
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Natural Hazards Mission Area, Geologic Hazards Science Center

Applying consequence-driven scenario selection to lifelines

We present a new consequence-driven framework for earthquake scenario selection. For emergency managers, utility operators, policy makers, and other stakeholders, a scenario-based seismic risk assessment is often necessary for the purpose of emergency management and planning. In developing a scientifically defensible scenario, stakeholders can simulate a realistic event in order to pre-identify vu
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Yolanda C Lin, David J. Wald, Eric M. Thompson, David Lallemant

Integrated strategies for enhanced rapid earthquake shaking, ground failure, and impact estimation employing remotely sensed and ground truth constraints

Estimating earthquake impacts using physical or empirical models is challenging because the three components of loss estimation-shaking, exposure, and vulnerabilities-entail inherent uncertainties. Loss modeling in near-real-time adds additional uncertainties, yet expectations for actionable information with a reasonable level of confidence in the results are real. The modeling approaches describe
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David J. Wald, Susu Xu, H. Noh, J. Dimasaka, Kishor Jaiswal, Kate E. Allstadt, Davis T. Engler

Improving the Development Pipelines for USGS Earthquake Hazards Program Real-Time and Scenario Products

The real-time and scenario products of the U.S. Geological Survey (USGS) Earthquake Hazards Program, such as the ComCat catalog, Did You Feel It?, ShakeMap, ShakeCast, and PAGER, are highly visible and used by a wide variety of stakeholders. We propose two significant enhancements to the development pipelines for the Earthquake Hazards Program real-time and scenario products that have far-reaching
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Brad T. Aagaard, David J. Wald, Eric M. Thompson, Mike Hearne, Lisa Sue Schleicher
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Natural Hazards Mission Area, Earthquake Hazards Program, Earthquake Science Center, Geologic Hazards Science Center

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,
Authors
David J. Wald
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Natural Hazards Mission Area, 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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Ganyu Teng, Jack W. Baker, David J. Wald
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Natural Hazards Mission Area, 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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Hae Young Noh, Kishor Jaiswal, Davis T. Engler, David J. Wald
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Natural Hazards Mission Area, 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
Authors
Kate E. Allstadt, Eric M. Thompson, Randall W. Jibson, David J. Wald, Mike Hearne, Edward J. Hunter, Jeremy Fee, Heather Schovanec, Daniel Slosky, Kirstie Lafon Haynie
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Natural Hazards Mission Area, Geologic Hazards Science Center

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.

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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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