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Peter Powers

I am a research and development geophysicist specializing in probabilisitic seismic hazard analysis.

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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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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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Data Release for PGV Data for the 2018 National Seismic Hazard Model for the Conterminous United States

Peak ground velocity (PGV) gridded probabilistic seismic hazard data for the updated 2018 National Seismic Hazard Model (NSHM) for the Conterminous United States (CONUS). PGV hazard curves and ground motions have been calculated on a 0.05 by 0.05 degree grid using the NSHM CONUS 2018 earthquake source model. PGV support has been incorporated into the NSHM using a newly developed PGV model conditio
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Geologic Hazards Science Center

Geologic Inputs for the 2023 Alaska Update to the U.S. National Seismic Hazard Model (NSHM)

This data release comprises three crustal (as opposed to subduction zone) geologic input datasets for the 2023 Alaska update to the U.S. National Seismic Hazard Model (NSHM): a fault sections map dataset, a fault zones map dataset, and an accompanying earthquake geology table.
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Alaska Science Center

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 up
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Geologic Hazards Science Center
Filter Total Items: 17

The 2018 update of the US National Seismic Hazard Model: Ground motion models in the central and eastern US

The United States Geological Survey (USGS) National Seismic Hazard Model (NSHM) is the scientific foundation of seismic design regulations in the United States and is regularly updated to consider the best available science and data. The 2018 update of the conterminous US NSHM includes major changes to the underlying ground motion models (GMMs). Most of the changes are motivated by the new multi-p
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Natural Hazards, Earthquake Hazards, Earthquake Science Center, Geologic Hazards Science Center

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
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Natural Hazards, Earthquake Hazards, Earthquake Science Center, Geologic Hazards Science Center

The 2018 update of the US National Seismic Hazard Model: Additional period and site class data

As part of the update of the 2018 National Seismic Hazard Model (NSHM) for the conterminous United States (CONUS), new ground motion and site effect models for the central and eastern United States were incorporated, as well as basin depths from local seismic velocity models in four western US (WUS) urban areas. These additions allow us, for the first time, to calculate probabilistic seismic hazar
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Natural Hazards, Geologic Hazards Science Center

Evaluation of ground‐motion models for U.S. Geological Survey seismic hazard forecasts: Hawaii tectonic earthquakes and volcanic eruptions

The selection and weighting of ground‐motion models (GMMs) introduces a significant source of uncertainty in U.S. Geological Survey (USGS) National Seismic Hazard Modeling Project (NSHMP) forecasts. In this study, we evaluate 18 candidate GMMs using instrumental ground‐motion observations of horizontal peak ground acceleration (PGA) and 5%‐damped pseudospectral acceleration (0.02–10 s) for tectoni
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Natural Hazards, Geologic Hazards Science Center

Evaluation of ground‐motion models for U.S. Geological Survey seismic hazard models: 2018 Anchorage, Alaska, Mw 7.1 subduction zone earthquake sequence

Instrumental ground‐motion recordings from the 2018 Anchorage, Alaska (⁠Mw 7.1), earthquake sequence provide an independent data set allowing us to evaluate the predictive power of ground‐motion models (GMMs) for intraslab earthquakes associated with the Alaska subduction zone. In this study, we evaluate 15 candidate GMMs using instrumental ground‐motion observations of peak ground acceleration an
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Natural Hazards, Geologic Hazards Science Center

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
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Natural Hazards, Geologic Hazards Science Center

Ground-motion amplification in Cook Inlet region, Alaska from intermediate-depth earthquakes, including the 2018 MW=7.1 Anchorage earthquake

We measure pseudospectral and peak ground motions from 44 intermediate‐depth Mw≥4.9 earthquakes in the Cook Inlet region of southern Alaska, including those from the 2018 Mw 7.1 earthquake near Anchorage, to identify regional amplification features (⁠0.1–5  s period). Ground‐motion residuals are computed with respect to an empirical ground‐motion model for intraslab subduction earthquakes, and we
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Natural Hazards, Earthquake Hazards, Geologic Hazards Science Center

Evaluation of ground motion models for USGS seismic hazard forecasts: Induced and tectonic earthquakes in the Central and Eastern U.S.

Ground motion model (GMM) selection and weighting introduces a significant source of uncertainty in United States Geological Survey (USGS) seismic hazard models. The increase in moderate moment magnitude induced earthquakes (Mw 4 to 5.8) in Oklahoma and Kansas since 2009, due to increased wastewater injection related to oil and gas production (Keranen et al., 2013; 2014; Weingarten et al., 2015;
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Natural Hazards, Earthquake Hazards, Geologic Hazards Science Center, Earthquake Science Center

Preliminary 2018 national seismic hazard model for the conterminous United States

The 2014 U.S. Geological Survey national seismic hazard model for the conterminous U.S. will be updated in 2018 and 2020 to coincide with the Building Seismic Safety Council’s Project 17 timeline for development of new building code design criteria. The two closely timed updates are planned to allow more time for the Provisions Update Committee to analyze the consequences of the hazard model chang
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Natural Hazards, Earthquake Hazards, Earthquake Science Center, Geologic Hazards Science Center

Ground motions from induced earthquakes in Oklahoma and Kansas

Improved predictions of earthquake ground motions are critical to advancing seismic hazard analyses and earthquake response. The high seismicity rate from 2009 to 2016 in Oklahoma and Kansas provides an extensive data set for examining the ground motions from these events. We evaluate the ability of three suites of ground‐motion prediction equations (GMPEs)—appropriate for modeling tectonic earthq
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Natural Hazards, Earthquake Hazards, Geologic Hazards Science Center

Additional period and site class maps for the 2014 National Seismic Hazard Model for the conterminous United States

The 2014 update of the U.S. Geological Survey (USGS) National Seismic Hazard Model (NSHM) for the conterminous United States (2014 NSHM; Petersen and others, 2014, 2015) included probabilistic ground motion maps for 2 percent and 10 percent probabilities of exceedance in 50 years, derived from seismic hazard curves for peak ground acceleration (PGA) and 0.2 and 1.0 second spectral accelerations (S
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Natural Hazards, Earthquake Hazards, Geologic Hazards Science Center

The science, engineering applications, and policy implications of simulation-based PSHA

We summarize scientific methods for developing probabilistic seismic hazard assessments from 3-D earthquake ground motion simulations, describe current use of simulated ground motions for engineering applications, and discuss on-going efforts to incorporate these effects in the U.S. national seismic hazard model. The 3-D simulations provide important, additional information about earthquake ground
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Natural Hazards, Earthquake Hazards, Earthquake Science Center, Geologic Hazards Science Center

nshm-fault-sections

A repository of all geologic fault section data included in USGS National Seismic Hazard Models
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Geologic Hazards Science Center

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