Ned Field
Ned (Edward) Field is a Research Geophysicist with the Earthquake Hazards Program.
Ned Field coordinates and leads the development of earthquake forecast models for the USGS Earthquake Hazards Program. These forecasts, coupled with ground-motion models, form the basis of modern seismic hazard and risk analyses. Their development is multidisciplinary and collaborative (a "systems science" problem) in that information from a broad range of disciplines (e.g., seismology, geodesy, geology, paleoseismology, and earthquake physics) must reconciled.
Recent accomplishments and ongoing challenges involve representation of multi-fault ruptures and spatiotemporal clustering (e.g., aftershocks), improved uncertainty estimates, applying more physics-based approaches, and the need to add "valuation" to our verification and validation protocols (i.e., a greater focus on usefulness). Ned is also involved in developing and deploying end-to-end seismic hazard and risk computational platforms. The resultant models influence a variety of risk mitigation activities, including construction requirements (building codes) and earthquake insurance rates.
Science and Products
Candidate products for operational earthquake forecasting illustrated using the HayWired planning scenario, including one very quick (and not‐so‐dirty) hazard‐map option
A prototype operational earthquake loss model for California based on UCERF3-ETAS – A first look at valuation
A synoptic view of the Third Uniform California Earthquake Rupture Forecast (UCERF3)
Trimming a hazard logic tree with a new model-order-reduction technique
A spatiotemporal clustering model for the Third Uniform California Earthquake Rupture Forecast (UCERF3‐ETAS): Toward an operational earthquake forecast
The potential uses of operational earthquake forecasting
Seismic source characterization for the 2014 update of the U.S. National Seismic Hazard Model
The 2014 United States National Seismic Hazard Model
The 2014 update to the National Seismic Hazard Model in California
UCERF3: A new earthquake forecast for California's complex fault system
Long‐term time‐dependent probabilities for the third Uniform California Earthquake Rupture Forecast (UCERF3)
Time‐dependent renewal‐model probabilities when date of last earthquake is unknown
New USGS map shows where damaging earthquakes are most likely to occur in US
USGS scientists and our partners recently revealed the latest National Seismic Hazard Model, showing that nearly 75% of the United States could experience a damaging earthquake, emphasizing seismic hazards span a significant part of the country.
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Candidate products for operational earthquake forecasting illustrated using the HayWired planning scenario, including one very quick (and not‐so‐dirty) hazard‐map option
In an effort to help address debates on the usefulness of operational earthquake forecasting (OEF), we illustrate a number of OEF products that could be automatically generated in near‐real time. To exemplify, we use an M 7.1 mainshock on the Hayward fault, which is very similar to the U.S. Geological Survey (USGS) HayWired earthquake planning scenario. Given that there is always some background lAuthorsEdward H. Field, Kevin R. MilnerA prototype operational earthquake loss model for California based on UCERF3-ETAS – A first look at valuation
We present a prototype operational loss model based on UCERF3-ETAS, which is the third Uniform California Earthquake Rupture Forecast with an Epidemic Type Aftershock Sequence (ETAS) component. As such, UCERF3-ETAS represents the first earthquake forecast to relax fault segmentation assumptions and to include multi-fault ruptures, elastic-rebound, and spatiotemporal clustering, all of which seem iAuthorsEdward H. Field, Keith Porter, Kevn MilnerA synoptic view of the Third Uniform California Earthquake Rupture Forecast (UCERF3)
Probabilistic forecasting of earthquake‐producing fault ruptures informs all major decisions aimed at reducing seismic risk and improving earthquake resilience. Earthquake forecasting models rely on two scales of hazard evolution: long‐term (decades to centuries) probabilities of fault rupture, constrained by stress renewal statistics, and short‐term (hours to years) probabilities of distributed sAuthorsEdward H. Field, Thomas H. Jordan, Morgan T. Page, Kevin R. Milner, Bruce E. Shaw, Timothy E. Dawson, Glenn Biasi, Thomas E. Parsons, Jeanne L. Hardebeck, Andrew J. Michael, Ray J. Weldon, Peter M. Powers, Kaj M. Johnson, Yuehua Zeng, Peter Bird, Karen Felzer, Nicholas van der Elst, Christopher Madden, Ramon Arrowsmith, Maximillan J. Werner, Wayne R. ThatcherTrimming a hazard logic tree with a new model-order-reduction technique
The size of the logic tree within the Uniform California Earthquake Rupture Forecast Version 3, Time-Dependent (UCERF3-TD) model can challenge risk analyses of large portfolios. An insurer or catastrophe risk modeler concerned with losses to a California portfolio might have to evaluate a portfolio 57,600 times to estimate risk in light of the hazard possibility space. Which branches of the logicAuthorsKeith Porter, Edward H. Field, Kevin R. MilnerA spatiotemporal clustering model for the Third Uniform California Earthquake Rupture Forecast (UCERF3‐ETAS): Toward an operational earthquake forecast
We, the ongoing Working Group on California Earthquake Probabilities, present a spatiotemporal clustering model for the Third Uniform California Earthquake Rupture Forecast (UCERF3), with the goal being to represent aftershocks, induced seismicity, and otherwise triggered events as a potential basis for operational earthquake forecasting (OEF). Specifically, we add an epidemic‐type aftershock sequAuthorsEdward H. Field, Kevin R. Milner, Jeanne L. Hardebeck, Morgan T. Page, Nicholas van der Elst, Thomas H. Jordan, Andrew J. Michael, Bruce E. Shaw, Maximillan J. WernerThe potential uses of operational earthquake forecasting
This article reports on a workshop held to explore the potential uses of operational earthquake forecasting (OEF). We discuss the current status of OEF in the United States and elsewhere, the types of products that could be generated, the various potential users and uses of OEF, and the need for carefully crafted communication protocols. Although operationalization challenges remain, there was cleAuthorsEdward H. Field, Thomas Jordan, Lucille M. Jones, Andrew Michael, Michael L. BlanpiedSeismic source characterization for the 2014 update of the U.S. National Seismic Hazard Model
We present the updated seismic source characterization (SSC) for the 2014 update of the National Seismic Hazard Model (NSHM) for the conterminous United States. Construction of the seismic source models employs the methodology that was developed for the 1996 NSHM but includes new and updated data, data types, source models, and source parameters that reflect the current state of knowledge of earthAuthorsMorgan P. Moschetti, Peter M. Powers, Mark D. Petersen, Oliver S. Boyd, Rui Chen, Edward H. Field, Arthur Frankel, Kathleen Haller, Stephen Harmsen, Charles S. Mueller, Russell Wheeler, Yuehua ZengThe 2014 United States National Seismic Hazard Model
New seismic hazard maps have been developed for the conterminous United States using the latest data, models, and methods available for assessing earthquake hazard. The hazard models incorporate new information on earthquake rupture behavior observed in recent earthquakes; fault studies that use both geologic and geodetic strain rate data; earthquake catalogs through 2012 that include new assessmeAuthorsMark D. Petersen, Morgan P. Moschetti, Peter M. Powers, Charles Mueller, Kathleen Haller, Arthur Frankel, Yuehua Zeng, Sanaz Rezaeian, Stephen Harmsen, Oliver S. Boyd, Edward H. Field, Rui Chen, Kenneth S. Rukstales, Nicolas Luco, Russell Wheeler, Robert Williams, Anna H. OlsenThe 2014 update to the National Seismic Hazard Model in California
The 2014 update to the U. S. Geological Survey National Seismic Hazard Model in California introduces a new earthquake rate model and new ground motion models (GMMs) that give rise to numerous changes to seismic hazard throughout the state. The updated earthquake rate model is the third version of the Uniform California Earthquake Rupture Forecast (UCERF3), wherein the rates of all ruptures are deAuthorsPeter M. Powers, Edward H. FieldUCERF3: A new earthquake forecast for California's complex fault system
With innovations, fresh data, and lessons learned from recent earthquakes, scientists have developed a new earthquake forecast model for California, a region under constant threat from potentially damaging events. The new model, referred to as the third Uniform California Earthquake Rupture Forecast, or "UCERF" (http://www.WGCEP.org/UCERF3), provides authoritative estimates of the magnitude, locatAuthorsEdward H. FieldLong‐term time‐dependent probabilities for the third Uniform California Earthquake Rupture Forecast (UCERF3)
The 2014 Working Group on California Earthquake Probabilities (WGCEP 2014) presents time-dependent earthquake probabilities for the third Uniform California Earthquake Rupture Forecast (UCERF3). Building on the UCERF3 time-independent model, published previously, renewal models are utilized to represent elastic-rebound-implied probabilities. A new methodology has been developed that solves applicaAuthorsEdward H. Field, Glenn P. Biasi, Peter Bird, Timothy E. Dawson, Karen R. Felzer, David A. Jackson, Kaj M. Johnson, Thomas H. Jordan, Christopher Madden, Andrew J. Michael, Kevin Milner, Morgan T. Page, Thomas E. Parsons, Peter Powers, Bruce E. Shaw, Wayne R. Thatcher, Ray J. Weldon, Yuehua ZengTime‐dependent renewal‐model probabilities when date of last earthquake is unknown
We derive time-dependent, renewal-model earthquake probabilities for the case in which the date of the last event is completely unknown, and compare these with the time-independent Poisson probabilities that are customarily used as an approximation in this situation. For typical parameter values, the renewal-model probabilities exceed Poisson results by more than 10% when the forecast duration excAuthorsEdward H. Field, Thomas H. Jordan - Software
- News
New USGS map shows where damaging earthquakes are most likely to occur in US
USGS scientists and our partners recently revealed the latest National Seismic Hazard Model, showing that nearly 75% of the United States could experience a damaging earthquake, emphasizing seismic hazards span a significant part of the country.