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
Filter Total Items: 61
The 2018 update of the US National Seismic Hazard Model: Where, why, and how much probabilistic ground motion maps changed
The 2018 US Geological Survey National Seismic Hazard Model (NSHM) incorporates new data and updated science to improve the underlying earthquake and ground motion forecasts for the conterminous United States. The NSHM considers many new data and component input models: (1) new earthquakes between 2013 and 2017 and updated earthquake magnitudes for some earlier earthquakes; (2) two updated smoothe
Authors
Mark D. Petersen, Allison Shumway, Peter M. Powers, Charles S Mueller, Morgan P. Moschetti, Arthur Frankel, Sanaz Rezaeian, Daniel McNamara, Nico Luco, Oliver S. Boyd, Kenneth S. Rukstales, Kishor S. Jaiswal, Eric M. Thompson, Susan M. Hoover, Brandon Clayton, Ned Field, Yuehua Zeng
Toward physics-based nonergodic PSHA: A prototype fully-deterministic seismic hazard model for southern California
We present a nonergodic framework for probabilistic seismic‐hazard analysis (PSHA) that is constructed entirely of deterministic, physical models. The use of deterministic ground‐motion simulations in PSHA calculations is not new (e.g., CyberShake), but prior studies relied on kinematic rupture generators to extend empirical earthquake rupture forecasts. Fully dynamic models, which simulate ruptur
Authors
Kevin R. Milner, Bruce E. Shaw, Christine A. Goulet, Keith B. Richards-Dinger, Scott Callaghan, Thomas H. Jordan, James H. Dieterich, Ned Field
Generalizing the inversion‐based PSHA source model for an interconnected fault system
This article represents a step toward generalizing and simplifying the procedure for constructing an inversion‐based seismic hazard source model for an interconnected fault system, including the specification of adjustable segmentation constraints. A very simple example is used to maximize understandability and to counter the notion that an inversion approach is only applicable when an abundance o
Authors
Ned Field, Kevin R. Milner, Morgan T. Page
Pseudo-prospective evaluation of UCERF3-ETAS forecasts during the 2019 Ridgecrest sequence
The 2019 Ridgecrest sequence provides the first opportunity to evaluate Uniform California Earthquake Rupture Forecast v.3 with epidemic‐type aftershock sequences (UCERF3‐ETAS) in a pseudoprospective sense. For comparison, we include a version of the model without explicit faults more closely mimicking traditional ETAS models (UCERF3‐NoFaults). We evaluate the forecasts with new metrics developed
Authors
William J. Savran, Maximillian J. Werner, W. Marzocchi, David A. Rhoades, David D. Jackson, Kevin R. Milner, Edward H. Field, Andrew J. Michael
Assessing the value of removing earthquake-hazard-related epistemic uncertainties, exemplified using average annual loss in California
To aid in setting scientific research priorities, we assess the potential value of removing each of the epistemic uncertainties currently represented in the US Geological Survey California seismic-hazard model, using average annual loss (AAL) as the risk metric of interest. Given all the uncertainties, represented with logic-tree branches, we find a mean AAL of $3.94 billion. The modal value is 17
Authors
Edward H. Field, Kevin R. Milner, Keith Porter
Probabilistic seismic hazard analysis at regional and national scale: State of the art and future challenges
Seismic hazard modelling is a multi-disciplinary science that aims to forecast earthquake occurrence and its resultant ground shaking. Such models consist of a probabilistic framework that quantifies uncertainty across a complex system; typically, this includes at least two model components developed from Earth science: seismic-source and ground-motion models. Although there is no scientific presc
Authors
M. C. Gerstenberger, W. Marzocchi, T. J. Allen, M. Pagani, Janice Adams, L. Danciu, Edward H. Field, H. Fujiwara, Nico Luco, K-F Ma, C. Meletti, Mark D. Petersen
Operational earthquake forecasting during the 2019 Ridgecrest, California, earthquake sequence with the UCERF3-ETAS model
The first Uniform California Earthquake Rupture Forecast, Version 3–epidemic‐type aftershock sequence (UCERF3‐ETAS) aftershock simulations were running on a high‐performance computing cluster within 33 min of the 4 July 2019 M 6.4 Searles Valley earthquake. UCERF3‐ETAS, an extension of the third Uniform California Earthquake Rupture Forecast (UCERF3), is the first comprehensive, fault‐based, epide
Authors
Kevin R. Milner, Edward H. Field, William H Savran, Morgan T. Page, Thomas H Jordan
An exploration of parametric earthquake risk transfer solutions that dynamically adapt to seismicity changes
(Re)insurance companies rely on earthquake risk models to estimate the frequency and severity of their potential financial losses. To protect themselves, they sometimes use parametric risk transfer solutions, which are derivative-form agreements that provide compensation as a function of routine measurable earthquake characteristics. These mechanisms typically remain in force for one to three year
Authors
Guillermo Franco, R Guidotti, Edward H. Field, K.R. Milner, Y.J. Lee, R. S. Stein
The 2018 update of the US National Seismic Hazard Model: Overview of model and implications
During 2017–2018, the National Seismic Hazard Model for the conterminous United States was updated as follows: (1) an updated seismicity catalog was incorporated, which includes new earthquakes that occurred from 2013 to 2017; (2) in the central and eastern United States (CEUS), new ground motion models were updated that incorporate updated median estimates, modified assessments of the associated
Authors
Mark D. Petersen, Allison Shumway, Peter M. Powers, Charles Mueller, Morgan P. Moschetti, Arthur Frankel, Sanaz Rezaeian, Daniel E. McNamara, Nico Luco, Oliver S. Boyd, Kenneth S. Rukstales, Kishor S. Jaiswal, Eric M. Thompson, Susan M. Hoover, Brandon Clayton, Edward H. Field, Yuehua Zeng
Relaxing segmentation on the Wasatch Fault Zone: Impact on seismic hazard
The multisegment Wasatch fault zone is a well-studied normal fault in the western United States that has paleoseismic evidence of recurrent Holocene surface-faulting earthquakes. Along the 270-km-long central part of the fault, four primary structural complexities provide possible along-strike limits to these ruptures and form the basis for models of fault segmentation. Here, we assess the impact
Authors
Alessandro Valentini, Christopher DuRoss, Edward H. Field, Ryan D. Gold, Richard W. Briggs, Francesco Visini, Bruno Pace
How physics‐based earthquake simulators might help improve earthquake forecasts
Questions have persisted on the usefulness of physics‐based earthquake simulators with respect to forecasting earthquakes, due mostly to the inevitable assumptions, approximations, and uncertainties. Whether any model is reliable or trustworthy depends entirely on what questions we are asking of it, so the point of this article is to outline a number of currently anticipated and desired inferences
Authors
Edward H. Field
Developing earthquake forecast templates for fast and effective communication
No abstract available.
Authors
Sara McBride, Andrew J. Michael, Anne M. Wein, Jeanne L. Hardebeck, Julia S. Becker, Sally H. Potter, Suzanne C. Perry, Morgan T. Page, Matthew Gerstenberger, Edward H. Field, Nicholas van der Elst
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.
Science and Products
Filter Total Items: 61
The 2018 update of the US National Seismic Hazard Model: Where, why, and how much probabilistic ground motion maps changed
The 2018 US Geological Survey National Seismic Hazard Model (NSHM) incorporates new data and updated science to improve the underlying earthquake and ground motion forecasts for the conterminous United States. The NSHM considers many new data and component input models: (1) new earthquakes between 2013 and 2017 and updated earthquake magnitudes for some earlier earthquakes; (2) two updated smoothe
Authors
Mark D. Petersen, Allison Shumway, Peter M. Powers, Charles S Mueller, Morgan P. Moschetti, Arthur Frankel, Sanaz Rezaeian, Daniel McNamara, Nico Luco, Oliver S. Boyd, Kenneth S. Rukstales, Kishor S. Jaiswal, Eric M. Thompson, Susan M. Hoover, Brandon Clayton, Ned Field, Yuehua Zeng
Toward physics-based nonergodic PSHA: A prototype fully-deterministic seismic hazard model for southern California
We present a nonergodic framework for probabilistic seismic‐hazard analysis (PSHA) that is constructed entirely of deterministic, physical models. The use of deterministic ground‐motion simulations in PSHA calculations is not new (e.g., CyberShake), but prior studies relied on kinematic rupture generators to extend empirical earthquake rupture forecasts. Fully dynamic models, which simulate ruptur
Authors
Kevin R. Milner, Bruce E. Shaw, Christine A. Goulet, Keith B. Richards-Dinger, Scott Callaghan, Thomas H. Jordan, James H. Dieterich, Ned Field
Generalizing the inversion‐based PSHA source model for an interconnected fault system
This article represents a step toward generalizing and simplifying the procedure for constructing an inversion‐based seismic hazard source model for an interconnected fault system, including the specification of adjustable segmentation constraints. A very simple example is used to maximize understandability and to counter the notion that an inversion approach is only applicable when an abundance o
Authors
Ned Field, Kevin R. Milner, Morgan T. Page
Pseudo-prospective evaluation of UCERF3-ETAS forecasts during the 2019 Ridgecrest sequence
The 2019 Ridgecrest sequence provides the first opportunity to evaluate Uniform California Earthquake Rupture Forecast v.3 with epidemic‐type aftershock sequences (UCERF3‐ETAS) in a pseudoprospective sense. For comparison, we include a version of the model without explicit faults more closely mimicking traditional ETAS models (UCERF3‐NoFaults). We evaluate the forecasts with new metrics developed
Authors
William J. Savran, Maximillian J. Werner, W. Marzocchi, David A. Rhoades, David D. Jackson, Kevin R. Milner, Edward H. Field, Andrew J. Michael
Assessing the value of removing earthquake-hazard-related epistemic uncertainties, exemplified using average annual loss in California
To aid in setting scientific research priorities, we assess the potential value of removing each of the epistemic uncertainties currently represented in the US Geological Survey California seismic-hazard model, using average annual loss (AAL) as the risk metric of interest. Given all the uncertainties, represented with logic-tree branches, we find a mean AAL of $3.94 billion. The modal value is 17
Authors
Edward H. Field, Kevin R. Milner, Keith Porter
Probabilistic seismic hazard analysis at regional and national scale: State of the art and future challenges
Seismic hazard modelling is a multi-disciplinary science that aims to forecast earthquake occurrence and its resultant ground shaking. Such models consist of a probabilistic framework that quantifies uncertainty across a complex system; typically, this includes at least two model components developed from Earth science: seismic-source and ground-motion models. Although there is no scientific presc
Authors
M. C. Gerstenberger, W. Marzocchi, T. J. Allen, M. Pagani, Janice Adams, L. Danciu, Edward H. Field, H. Fujiwara, Nico Luco, K-F Ma, C. Meletti, Mark D. Petersen
Operational earthquake forecasting during the 2019 Ridgecrest, California, earthquake sequence with the UCERF3-ETAS model
The first Uniform California Earthquake Rupture Forecast, Version 3–epidemic‐type aftershock sequence (UCERF3‐ETAS) aftershock simulations were running on a high‐performance computing cluster within 33 min of the 4 July 2019 M 6.4 Searles Valley earthquake. UCERF3‐ETAS, an extension of the third Uniform California Earthquake Rupture Forecast (UCERF3), is the first comprehensive, fault‐based, epide
Authors
Kevin R. Milner, Edward H. Field, William H Savran, Morgan T. Page, Thomas H Jordan
An exploration of parametric earthquake risk transfer solutions that dynamically adapt to seismicity changes
(Re)insurance companies rely on earthquake risk models to estimate the frequency and severity of their potential financial losses. To protect themselves, they sometimes use parametric risk transfer solutions, which are derivative-form agreements that provide compensation as a function of routine measurable earthquake characteristics. These mechanisms typically remain in force for one to three year
Authors
Guillermo Franco, R Guidotti, Edward H. Field, K.R. Milner, Y.J. Lee, R. S. Stein
The 2018 update of the US National Seismic Hazard Model: Overview of model and implications
During 2017–2018, the National Seismic Hazard Model for the conterminous United States was updated as follows: (1) an updated seismicity catalog was incorporated, which includes new earthquakes that occurred from 2013 to 2017; (2) in the central and eastern United States (CEUS), new ground motion models were updated that incorporate updated median estimates, modified assessments of the associated
Authors
Mark D. Petersen, Allison Shumway, Peter M. Powers, Charles Mueller, Morgan P. Moschetti, Arthur Frankel, Sanaz Rezaeian, Daniel E. McNamara, Nico Luco, Oliver S. Boyd, Kenneth S. Rukstales, Kishor S. Jaiswal, Eric M. Thompson, Susan M. Hoover, Brandon Clayton, Edward H. Field, Yuehua Zeng
Relaxing segmentation on the Wasatch Fault Zone: Impact on seismic hazard
The multisegment Wasatch fault zone is a well-studied normal fault in the western United States that has paleoseismic evidence of recurrent Holocene surface-faulting earthquakes. Along the 270-km-long central part of the fault, four primary structural complexities provide possible along-strike limits to these ruptures and form the basis for models of fault segmentation. Here, we assess the impact
Authors
Alessandro Valentini, Christopher DuRoss, Edward H. Field, Ryan D. Gold, Richard W. Briggs, Francesco Visini, Bruno Pace
How physics‐based earthquake simulators might help improve earthquake forecasts
Questions have persisted on the usefulness of physics‐based earthquake simulators with respect to forecasting earthquakes, due mostly to the inevitable assumptions, approximations, and uncertainties. Whether any model is reliable or trustworthy depends entirely on what questions we are asking of it, so the point of this article is to outline a number of currently anticipated and desired inferences
Authors
Edward H. Field
Developing earthquake forecast templates for fast and effective communication
No abstract available.
Authors
Sara McBride, Andrew J. Michael, Anne M. Wein, Jeanne L. Hardebeck, Julia S. Becker, Sally H. Potter, Suzanne C. Perry, Morgan T. Page, Matthew Gerstenberger, Edward H. Field, Nicholas van der Elst
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.