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
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
Data Release for the 2023 U.S. 50-State National Seismic Hazard Model - Overview
Earthquake geology inputs for the U.S. National Seismic Hazard Model (NSHM) 2023 (western U.S.) (ver. 3.0, December 2023)
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
The 2023 US 50-State National Seismic Hazard Model: Overview and implications
The USGS 2023 Conterminous U.S. time‐independent earthquake rupture forecast
We present the 2023 U.S. Geological Survey time‐independent earthquake rupture forecast for the conterminous United States, which gives authoritative estimates of the magnitude, location, and time‐averaged frequency of potentially damaging earthquakes throughout the region. In addition to updating virtually all model components, a major focus has been to provide a better representation of epistemi
A comprehensive fault system inversion approach: Methods and application to NSHM23
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
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
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
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
Data Release for the 2023 U.S. 50-State National Seismic Hazard Model - Overview
Earthquake geology inputs for the U.S. National Seismic Hazard Model (NSHM) 2023 (western U.S.) (ver. 3.0, December 2023)
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
The 2023 US 50-State National Seismic Hazard Model: Overview and implications
The USGS 2023 Conterminous U.S. time‐independent earthquake rupture forecast
We present the 2023 U.S. Geological Survey time‐independent earthquake rupture forecast for the conterminous United States, which gives authoritative estimates of the magnitude, location, and time‐averaged frequency of potentially damaging earthquakes throughout the region. In addition to updating virtually all model components, a major focus has been to provide a better representation of epistemi
A comprehensive fault system inversion approach: Methods and application to NSHM23
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
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
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.