I specialize in the development of earthquake-forecast models, which are one of the two main modeling components used in modern seismic-hazard analysis (the other being a ground-motion model).
My focus area has mainly been California, which due to an abundance of riches in terms of both scientific talent and data constraints, has enabled the forging of state-or-the-art methodologies (California also hosts trillions of dollars in assets and, consequently, two-thirds of the nationwide seismic risk). The multi-disciplinary nature of earthquake forecasting necessitates a collaborative approach, which we have achieved through the Working Group on California Earthquake Probabilities (www.WGCEP.org). I led the development of our most recent model, the Third Uniform California Earthquake Rupture Forecast (UCERF3; www.WGCEP.org/UCERF3), which is innovative in terms of representing both multi-fault ruptures and spatiotemporal clustering (e.g. aftershocks); the relevance of both these effects was dramatically exemplified in a recent sequence of damaging earthquakes in New Zealand. Our forecast models influence a variety of risk mitigation activities, including construction requirements (building codes) and insurance rates. Important themes going forward include: a better quantification of uncertainties; the use of more physics-based approaches; and the need to add “valuation” to our verification and validation protocols (“all models are wrong” at some level, so a relevant question is whether a new and improved one really represents value added with respect to risk assessment).
I have also led the development of OpenSHA (http://www.OpenSHA.org), which is an object-oriented, GUI-enabled, open-source, and platform-independent computational framework for conducting seismic hazard analysis. OpenSHA also makes use of distributed object technologies (components can exist anywhere over the Internet), it runs on high-performance super computers, and it supports loss modeling as well.
I am also a member of the planning committee of the Southern California Earthquake Center (http://www.SCEC.org), and as such, I help formulated the SCEC science plan, write the annual RFPs, and review and recommend funding levels for proposals submitted to SCEC.
Science and Products
External Grants - Overview
Could the M7.1 Ridgecrest, CA Earthquake Sequence Trigger a Large Earthquake Nearby?
Operational Earthquake Forecasting – Implementing a Real-Time System for California
Joint USGS - GEM Group on Global Probabilistic Modeling of Earthquake Recurrence Rates and Maximum Magnitudes
Earthquake geology inputs for the U.S. National Seismic Hazard Model (NSHM) 2023, version 1.0
Shakemap earthquake scenario: Building Seismic Safety Council 2014 Event Set (BSSC2014)
Seismic-hazard maps for the conterminous United States, 2014
Seismic-Hazard Maps for the Conterminous United States, 2008
Western U.S. deformation models for the 2023 update to the U.S. National Seismic Hazard Model
Simplifying complex fault data for systems-level analysis: Earthquake geology inputs for U.S. NSHM 2023
Enumerating plausible multifault ruptures in complex fault systems with physical constraints
Some systemic risks to progress on seismic hazard assessment
STEPS: Slip time earthquake path simulations applied to the San Andreas and Toe Jam Hill Faults to redefine geologic slip rate uncertainty
The seismic hazard implications of declustering and poisson assumptions inferred from a fully time‐dependent model
Improvements to the Third Uniform California Earthquake Rupture Forecast ETAS Model (UCERF3‐ETAS)
The 2018 update of the US National Seismic Hazard Model: Where, why, and how much probabilistic ground motion maps changed
Toward physics-based nonergodic PSHA: A prototype fully-deterministic seismic hazard model for southern California
Generalizing the inversion‐based PSHA source model for an interconnected fault system
Pseudo-prospective evaluation of UCERF3-ETAS forecasts during the 2019 Ridgecrest sequence
Assessing the value of removing earthquake-hazard-related epistemic uncertainties, exemplified using average annual loss in California
STEPS: Slip Time Earthquake Path Simulations applied to the San Andreas and Toe Jam Hill faults to redefine geologic slip rate uncertainty (Matlab code)
nshm-fault-sections
Science and Products
- Science
External Grants - Overview
The U.S. Geological Survey (USGS) provides support for research that will assist in achieving the goals of the Earthquake Hazards Program. The goal is to mitigate earthquake losses that can occur in many parts of the nation by providing earth science data and assessments essential for land-use planning, engineering design, and emergency preparedness decisions.Could the M7.1 Ridgecrest, CA Earthquake Sequence Trigger a Large Earthquake Nearby?
Release Date: SEPTEMBER 30, 2019 Two of the first questions that come to mind for anyone who just felt an earthquake are, “Will there be another one?” and “Will it be larger?”.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...Joint USGS - GEM Group on Global Probabilistic Modeling of Earthquake Recurrence Rates and Maximum Magnitudes
Despite the best monitoring networks, the highest rate of earthquakes and the longest continuous recorded history in the world, this year’s M=9.0 Tohoku, Japan, earthquake was completely unforeseen. The Japanese had expected no larger than a M=8 quake in the Japan trench, 1/30 th the size of the Tohoku temblor. This year also saw the devastating M=6.3 Christchurch, New Zealand earthquake and the M... - Data
Earthquake geology inputs for the U.S. National Seismic Hazard Model (NSHM) 2023, version 1.0
This Data Release contains preliminary versions of two related databases: 1) A fault sections database ("NSHM2023_FaultSections_v1"), which depicts the geometry of faults capable of hosting independent earthquakes, and 2) An earthquake geology site information database ("NSHM2023_EQGeoDB_v1"), which contains fault slip-rate constraints at points. These databases were prepared in anticipation of upShakemap 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). - Maps
Seismic-hazard maps for the conterminous United States, 2014
The maps presented here provide an update to the 2008 data contained in U.S Geological Survey Scientific Investigations Map 3195 (http://pubs.usgs.gov/sim/3195/).Probabilistic seismic-hazard maps were prepared for the conterminous United States for 2014 portraying peak horizontal acceleration and horizontal spectral response acceleration for 0.2- and 1.0-second periods with probabilities of exceedSeismic-Hazard Maps for the Conterminous United States, 2008
Probabilistic seismic-hazard maps were prepared for the conterminous United States portraying peak horizontal acceleration and horizontal spectral response acceleration for 0.2- and 1.0-second periods with probabilities of exceedance of 10 percent in 50 years and 2 percent in 50 years. All of the maps were prepared by combining the hazard derived from spatially smoothed historic seismicity with th - Publications
Filter Total Items: 54
Western U.S. deformation models for the 2023 update to the U.S. National Seismic Hazard Model
This report describes geodetic and geologic information used to constrain deformation models of the 2023 update to the National Seismic Hazard Model (NSHM), a set of deformation models to interpret these data, and their implications for earthquake rates in the western United States. Recent updates provide a much larger data set of Global Positioning System crustal velocities than used in the 2014AuthorsFred Pollitz, Eileen L. Evans, Edward H. Field, Alexandra Elise Hatem, Elizabeth H. Hearn, Kaj M Johnson, Jessica R. Murray, Peter M. Powers, Zheng-Kang Shen, Crystal Wespestad, Yuehua ZengSimplifying complex fault data for systems-level analysis: Earthquake geology inputs for U.S. NSHM 2023
As part of the U.S. National Seismic Hazard Model (NSHM) update planned for 2023, two databases were prepared to more completely represent Quaternary-active faulting across the western United States: the NSHM23 fault sections database (FSD) and earthquake geology database (EQGeoDB). In prior iterations of NSHM, fault sections were included only if a field-measurement-derived slip rate was estimateAuthorsAlexandra Elise Hatem, Camille Marie Collett, Richard W. Briggs, Ryan D. Gold, Stephen J. Angster, Edward H. Field, Peter M. PowersEnumerating plausible multifault ruptures in complex fault systems with physical constraints
We propose a new model for determining the set of plausible multifault ruptures in an interconnected fault system. We improve upon the rules used in the Third Uniform California Earthquake Rupture Forecast (UCERF3) to increase connectivity and the physical consistency of ruptures. We replace UCERF3’s simple azimuth change rules with new Coulomb favorability metrics and increase the maximum jump diAuthorsKevin R. Milner, Bruce E. Shaw, Edward H. FieldSome systemic risks to progress on seismic hazard assessment
No abstract available.AuthorsEdward H. FieldSTEPS: Slip time earthquake path simulations applied to the San Andreas and Toe Jam Hill Faults to redefine geologic slip rate uncertainty
Geologic slip rates are a time-averaged measurement of fault displacement calculated over hundreds to million-year time scales and are a primary input for probabilistic seismic hazard analyses, which forecast expected ground shaking in future earthquakes. Despite their utility for seismic hazard calculations, longer-term geologic slip rates represent a time-averaged measure of the tempo of strainAuthorsAlexandra Elise Hatem, Ryan D. Gold, Richard W. Briggs, Katherine Scharer, Edward H. FieldThe seismic hazard implications of declustering and poisson assumptions inferred from a fully time‐dependent model
We use the Third Uniform California Earthquake Rupture Forecast (UCERF3) epidemic‐type aftershock sequence (ETAS) model (UCERF3‐ETAS) to evaluate the effects of declustering and Poisson assumptions on seismic hazard estimates. Although declustering is necessary to infer the long‐term spatial distribution of earthquake rates, the question is whether it is also necessary to honor the Poisson assumptAuthorsEdward H. Field, Kevin R. Milner, Nicolas LucoImprovements to the Third Uniform California Earthquake Rupture Forecast ETAS Model (UCERF3‐ETAS)
We describe recent improvements to the Third Uniform California Earthquake Rupture Forecast ETAS Model (UCERF3‐ETAS), which continues to represent our most advanced and complete earthquake forecast in terms of relaxing segmentation assumptions and representing multifault ruptures, elastic‐rebound effects, and spatiotemporal clustering (the latter to represent aftershocks and otherwise triggered evAuthorsEdward H. Field, Kevin R. Milner, Morgan T. Page, William H. Savran, Nicholas van der ElstThe 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 smootheAuthorsMark D. Petersen, Allison Shumway, Peter M. Powers, Charles S Mueller, Morgan P. Moschetti, Arthur Frankel, Sanaz Rezaeian, Daniel McNamara, Nicolas Luco, Oliver S. Boyd, Kenneth S. Rukstales, Kishor Jaiswal, Eric M. Thompson, Susan M. Hoover, Brandon Clayton, Edward H. Field, Yuehua ZengToward 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 rupturAuthorsKevin R. Milner, Bruce E. Shaw, Christine A. Goulet, Keith B. Richards-Dinger, Scott Callaghan, Thomas H. Jordan, James H. Dieterich, Edward H. FieldGeneralizing 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 oAuthorsEdward H. Field, Kevin R. Milner, Morgan T. PagePseudo-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 developedAuthorsWilliam J. Savran, Maximillian J. Werner, W. Marzocchi, David A. Rhoades, David D. Jackson, Kevin R. Milner, Edward H. Field, Andrew J. MichaelAssessing 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 17AuthorsEdward H. Field, Kevin R. Milner, Keith Porter - Software
STEPS: Slip Time Earthquake Path Simulations applied to the San Andreas and Toe Jam Hill faults to redefine geologic slip rate uncertainty (Matlab code)
Geologic slip rates are a time-averaged measurement of fault displacement calculated over 100s- to 1,000,000-year time scales and are a primary input for probabilistic seismic hazard analyses (PSHA), which forecast expected ground shaking in future earthquakes. Despite their utility for seismic hazard calculations, longer-term geologic slip rates represent a time-averaged measure of the tempo of snshm-fault-sections
A repository of all geologic fault section data included in USGS National Seismic Hazard Models