My research is focused on how to best describe the behavior of active faults in the recent past. I use methods such as paleoseismology, slip rate studies, topographic analysis, numerical modeling and tectonic reconstructions to understand how earthquakes occur in space and time, both on single faults and within larger fault systems.
Overall, I am interested in how faults evolve over time and characterizing variability and evolution of fault behavior on across different space-time scales. An overarching goal of my work is to understand how to represent geological constraints within hazard models, like the National Seismic Hazard Map and the Uniform California Earthquake Rupture Forecast.
Professional Experience
Research Geologist: USGS-GHSC, 2020-present
Mendenhall post-doctoral fellow: USGS-GHSC, 2019-2020
Education
PhD: University of Southern California, 2019
MS: University of Massachusetts, Amherst, 2014
BA: Wellesley College, 2012
Science and Products
Fault Rupture Mapping of the 6 February 2023 Kahramanmaraş, Türkiye, Earthquake Sequence from Satellite Data
This data release contains two datasets that depict fault rupture on the East Anatolian and Çardak faults resulting from the Mw7.8 and Mw7.5 earthquakes in Turkey (Türkiye). It contains two additional datasets that describe satellite imagery coverage and observation gaps. The 6 February 2023 earthquake sequence caused >500 km of combined surface rupture on the primarily left-lateral strike-slip Ea
Western U.S. geologic deformation model for use in the U.S. National Seismic Hazard Model 2023, version 1.0
The U.S. National Seismic Hazard Model (NSHM) relies on deformation models to assign slip rates along active faults used in the earthquake rupture forecast. Here, we present the geologic deformation model results in tabular form. We provide model outputs in multiple file formats, as well as the polygons used in analyses throughout the geologic deformation model process.The data presented herein ar
Geodetic deformation model results and corrections for use in U.S. National Seismic Hazard Model 2023
This page houses model results used in the U.S. National Seismic Hazard Model, 2023. We include results from four geodetic deformation models (Pollitz, Zeng, Shen, Evans), post-seismic relaxation ("ghost transient") calculation (Hearn), and creep calculation (Johnson/Murray). Geologic deformation model results are available in Hatem et al. (2022a).
An overview of all model procedures and comparis
Plotting multiple fault representations: Applications for National Seismic Hazard Model 2023 update (NSHM-faultmaps)
The National Seismic Hazard Model (NSHM) utilizes a fault sections database (FSD) throughout the model workflow. Working towards a 2023 NSHM release, the NSHM23 FSD encompasses a major update with the addition of new fault sections, as well as the revision of existing fault sections from prior FSD (2014). The additions and revisions were largely based on the U.S. Geological Survey's Quaternary Fau
Compilation of geologic slip rate constraints used in 1996-2014 U.S. National Seismic Hazard Models (ver. 2.0, February 2022)
A key input for probabilistic seismic hazard analysis (PSHA) is geologic slip rate data. Here, we compile all geologic slip rates that are reportedly used in U.S. National Seismic Hazard Map (NSHM) releases from 1996, 2002, 2007, 2008, and 2014. Although a new NSHM was released in 2018, no changes were made in geologic slip rate data used. The geologic slip rates are collated from existing NSHM re
Earthquake geology inputs for the U.S. National Seismic Hazard Model (NSHM) 2023 (western US) (ver. 2.0, February 2022)
This Data Release contains preliminary versions of two related databases: 1) A fault sections database ('NSHM23_FSD_v2'), which depicts the geometry of faults capable of hosting independent earthquakes, and 2) An earthquake geology site information database ('NSHM23_EQGeoDB_v2'), which contains fault slip-rate constraints at points. These databases were prepared in anticipation of updates to the N
Summary of proposed changes to geologic inputs for the U.S. National Seismic Hazard Model (NSHM) 2023, version 1.0
This data release documents proposed updates to geologic inputs (faults) for the upcoming 2023 National Seismic Hazard Model (NSHM). This version (1.0) conveys differences between 2014 NSHM fault sources and those recently released in the earthquake geology inputs for the U.S. National Seismic Hazard Model (NSHM) 2023, version 1.0 data release by Hatem et al. (2021). A notable difference between t
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
Compilation of geologic slip rate constraints used in 1996 - 2014 U.S. National Seismic Hazard Maps
A key input for probabilistic seismic hazard analysis (PSHA) is geologic slip rate data. Yet, no single database exists to house all geologic slip rate data used in these calculations. Here, we compile all geologic slip rates that are reportedly used in U.S. National Seismic Hazard Map (NSHM) releases from 1996, 2002, 2007, 2008, and 2014. Although a new NSHM was released in 2018, no changes were
Surface Rupture Map of the 2020 M 6.5 Monte Cristo Range earthquake, Esmeralda and Mineral counties, Nevada
The 15 May 2020, M6.5 Monte Cristo Range earthquake was the largest earthquake in Nevada in over 66 years and occurred in a sparsely populated area of western Nevada about 74 km southeast of the town of Hawthorne. The earthquake produced surface rupture distributed across a 28-km-long zone along the eastward projection of the Candelaria fault in the Mina deflection of the central Walker Lane. Post
Rapid surface rupture mapping from satellite data: The 2023 Kahramanmaraş, Turkey (Türkiye), earthquake sequence
The 6 February 2023 Kahramanmaraş, Turkey (Türkiye), earthquake sequence produced > 500 km of surface rupture primarily on the left‐lateral East Anatolian (~345 km) and Çardak (~175 km) faults. Constraining the length and magnitude of surface displacement on the causative faults is critical for loss estimates, recovery efforts, rapid identification of impacted infrastructure, and fault displacemen
Authors
Nadine G. Reitman, Richard W. Briggs, William D. Barnhart, Alexandra Elise Hatem, Jessica Ann Thompson Jobe, Christopher DuRoss, Ryan D. Gold, John David Mejstrik, Camille Collett, Richard D Koehler, Sinan Akçiz
Rapid characterization of the February 2023 Kahramanmaraş, Turkey, earthquake sequence
The 6 February 2023 Mw 7.8 Pazarcık and subsequent Mw 7.5 Elbistan earthquakes generated strong ground shaking that resulted in catastrophic human and economic loss across south‐central Türkiye and northwest Syria. The rapid characterization of the earthquakes, including their location, size, fault geometries, and slip kinematics, is critical to estimate the impact of significant seismic events.
Authors
Dara Elyse Goldberg, Tuncay Taymaz, Nadine G. Reitman, Alexandra Elise Hatem, Seda Yolsal-Çevikbilen, William D. Barnhart, Tahir Serkan Irmak, David J. Wald, Taylan Öcalan, William L. Yeck, Berkan Özkan, Jessica Ann Thompson Jobe, David R. Shelly, Eric M. Thompson, Christopher DuRoss, Paul S. Earle, Richard W. Briggs, Harley M. Benz, Ceyhun Erman, Ali Hasan Doğan, Cemali Altuntaş
Preface to the focus section on deformation models for the U.S. National Seismic Hazard Model
No abstract available.
Authors
Fred Pollitz, Alexandra Elise Hatem, Kaj M. Johnson
Western U.S. geologic deformation model for use in the U.S. National Seismic Hazard Model 2023
Fault geometry and slip rates are key input data for geologic deformation models, which are a fundamental component of probabilistic seismic hazard analyses (PSHAs). However, geologic sources for PSHA have traditionally been limited to faults with field‐based slip rate constraints, which results in underrepresentation of known, but partially characterized, active faults. Here, we evaluate fault ge
Authors
Alexandra Elise Hatem, Nadine G. Reitman, Richard W. Briggs, Ryan D. Gold, Jessica Ann Thompson Jobe, Reed J. Burgette
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 2014
Authors
Fred 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 Zeng
Simplifying 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 estimate
Authors
Alexandra Elise Hatem, Camille Marie Collett, Richard W. Briggs, Ryan D. Gold, Stephen J. Angster, Edward H. Field, Peter M. Powers
How similar was the 1983 Mw 6.9 Borah Peak earthquake rupture to its surface-faulting predecessors along the northern Lost River fault zone (Idaho, USA)?
We excavated trenches at two paleoseismic sites bounding a trans-basin bedrock ridge (the Willow Creek Hills) along the northern Lost River fault zone to explore the uniqueness of the 1983 Mw 6.9 Borah Peak earthquake compared to its prehistoric predecessors. At the Sheep Creek site on the southernmost Warm Springs section, two earthquakes occurred at 9.8−14.0 ka (95% confidence) and 6.5−7.1 ka; e
Authors
Christopher DuRoss, Richard W. Briggs, Ryan D. Gold, Alexandra Elise Hatem, Austin John Elliott, Jaime Delano, Ivan Medina-Cascales, Harrison J. Gray, Shannon A. Mahan, Sylvia Nicovich, Zachery Lifton, Emily J. Kleber, Greg N. McDonald, Adam Hiscock, Mike Bunds, Nadine G. Reitman
STEPS: 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 strain
Authors
Alexandra Elise Hatem, Ryan D. Gold, Richard W. Briggs, Katherine Scharer, Edward H. Field
Field response and surface rupture characteristics of the 2020 M6.5 Monte Cristo Range earthquake, central Walker Lane, Nevada
The M 6.5 Monte Cristo Range earthquake that occurred in the central Walker Lane on 15 May 2020 was the largest earthquake in Nevada in 66 yr and resulted in a multidisciplinary scientific field response. The earthquake was the result of left‐lateral slip along largely unmapped parts of the Candelaria fault, one of a series of east–northeast‐striking faults that comprise the Mina deflection, a maj
Authors
Richard D Koehler, Seth Dee, Austin John Elliott, Alexandra Elise Hatem, Alexandra Pickering, Ian Pierce, Gordon G. Seitz
Documentation of Surface Fault Rupture and Ground‐Deformation Features Produced by the 4 and 5 July 2019 Mw 6.4 and Mw 7.1 Ridgecrest Earthquake Sequence
The MwMw 6.4 and MwMw 7.1 Ridgecrest earthquake sequence occurred on 4 and 5 July 2019 within the eastern California shear zone of southern California. Both events produced extensive surface faulting and ground deformation within Indian Wells Valley and Searles Valley. In the weeks following the earthquakes, more than six dozen scientists from government, academia, and the private sector carefully
Authors
Daniel J. Ponti, James Luke Blair, Rosa Carla M, Kate Thomas, Alexandra Pickering, Sinan Akciz, Stephen J. Angster, Jean-Philipe Avouac, Jeffrey Bachhuber, Steven Bacon, Nicolas C. Barth, S. Bennett, Kelly Blake, Stephan Bork, Benjamin A. Brooks, Thomas Bullard, Paul A. Burgess, Colin Chupik, Timothy E. Dawson, Michael DeFrisco, Jaime E. Delano, Stephen B. DeLong, James D. Dolan, Andrea Donnellan, Christopher DuRoss, Todd Ericksen, Erik Frost, Gareth J. Funning, Ryan D. Gold, Nicholas A Graehl, Carlos Gutierrez, Elizabeth Haddon, Alexandra Elise Hatem, John Helms, Janis Hernandez, Christopher S. Hitchcock, Peter Holland, Kenneth W. Hudnut, Katherine J. Kendrick, Richard D Koehler, Ozgur Kozaci, Tyler C. Ladinsky, Robert Leeper, Christopher Madugo, Maxime Mareschal, James McDonald, Devin McPhillips, Christopher Milliner, Daniel Mongovin, Alexander Morelan, Stephanie Nale, Johanna Nevitt, Matt O'Neal, Brian J. Olsen, Michael Oskin, Salena Padilla, Jason Patton, Belle E. Philibosian, Ian Pierce, Cynthia Pridmore, Nathaniel Roth, David Sandwell, Katherine Scharer, Gordon G. Seitz, Drake Singleton, Bridget Smith-Konter, Eleanor Spangler, Brian J. Swanson, Jessica Thompson Jobe, Jerome Treiman, Francesca Valencia, Joshua Vanderwal, Alana Williams, Xiaohua Xu, Judith Zachariasen, Jade Zimmerman, Robert Zinke
Surface displacement distributions for the July 2019 Ridgecrest, California earthquake ruptures
Surface rupture in the 2019 Ridgecrest, California, earthquake sequence occurred along two orthogonal cross faults and includes dominantly left‐lateral and northeast‐striking rupture in the Mw 6.4 foreshock and dominantly right‐lateral and northwest‐striking rupture in the Mw 7.1 mainshock. We present >650 field‐based, surface‐displacement observations for these ruptures and synthesize our results
Authors
Christopher DuRoss, Ryan D. Gold, Timothy E. Dawson, Katherine Scharer, Katherine J. Kendrick, Sinan Akciz, Stephen J. Angster, Jeffery Bachhuber, Steven Bacon, Scott E. K. Bennett, Luke Blair, Benjamin A. Brooks, Thomas Bullard, W. Paul Burgess, Colin Chupik, Michael DeFrisco, Jaime Delano, James D. Dolan, Erik Frost, Nick Graehl, Elizabeth Haddon, Alexandra Elise Hatem, Janis Hernandez, Christopher S. Hitchcock, Kennth Hudnut, Jessica Thompson Jobe, Richard D Koehler, Ozgur Kozaci, Tyler C. Ladinsky, Christopher Madugo, Devin McPhillips, Christopher Milliner, Alexander Morelan, Brian Olson, Jason Patton, Belle E. Philibosian, Alexandra J. Pickering, Ian Pierce, Daniel J. Ponti, Gordon G. Seitz, Eleanor Spangler, Brian J. Swanson, Kate Thomas, Jerome Treiman, Francesca Valencia, Alana Williams, Robert Zinke
Non-USGS Publications**
**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.
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 s
Science and Products
- Data
Fault Rupture Mapping of the 6 February 2023 Kahramanmaraş, Türkiye, Earthquake Sequence from Satellite Data
This data release contains two datasets that depict fault rupture on the East Anatolian and Çardak faults resulting from the Mw7.8 and Mw7.5 earthquakes in Turkey (Türkiye). It contains two additional datasets that describe satellite imagery coverage and observation gaps. The 6 February 2023 earthquake sequence caused >500 km of combined surface rupture on the primarily left-lateral strike-slip EaWestern U.S. geologic deformation model for use in the U.S. National Seismic Hazard Model 2023, version 1.0
The U.S. National Seismic Hazard Model (NSHM) relies on deformation models to assign slip rates along active faults used in the earthquake rupture forecast. Here, we present the geologic deformation model results in tabular form. We provide model outputs in multiple file formats, as well as the polygons used in analyses throughout the geologic deformation model process.The data presented herein arGeodetic deformation model results and corrections for use in U.S. National Seismic Hazard Model 2023
This page houses model results used in the U.S. National Seismic Hazard Model, 2023. We include results from four geodetic deformation models (Pollitz, Zeng, Shen, Evans), post-seismic relaxation ("ghost transient") calculation (Hearn), and creep calculation (Johnson/Murray). Geologic deformation model results are available in Hatem et al. (2022a). An overview of all model procedures and comparisPlotting multiple fault representations: Applications for National Seismic Hazard Model 2023 update (NSHM-faultmaps)
The National Seismic Hazard Model (NSHM) utilizes a fault sections database (FSD) throughout the model workflow. Working towards a 2023 NSHM release, the NSHM23 FSD encompasses a major update with the addition of new fault sections, as well as the revision of existing fault sections from prior FSD (2014). The additions and revisions were largely based on the U.S. Geological Survey's Quaternary FauCompilation of geologic slip rate constraints used in 1996-2014 U.S. National Seismic Hazard Models (ver. 2.0, February 2022)
A key input for probabilistic seismic hazard analysis (PSHA) is geologic slip rate data. Here, we compile all geologic slip rates that are reportedly used in U.S. National Seismic Hazard Map (NSHM) releases from 1996, 2002, 2007, 2008, and 2014. Although a new NSHM was released in 2018, no changes were made in geologic slip rate data used. The geologic slip rates are collated from existing NSHM reEarthquake geology inputs for the U.S. National Seismic Hazard Model (NSHM) 2023 (western US) (ver. 2.0, February 2022)
This Data Release contains preliminary versions of two related databases: 1) A fault sections database ('NSHM23_FSD_v2'), which depicts the geometry of faults capable of hosting independent earthquakes, and 2) An earthquake geology site information database ('NSHM23_EQGeoDB_v2'), which contains fault slip-rate constraints at points. These databases were prepared in anticipation of updates to the NSummary of proposed changes to geologic inputs for the U.S. National Seismic Hazard Model (NSHM) 2023, version 1.0
This data release documents proposed updates to geologic inputs (faults) for the upcoming 2023 National Seismic Hazard Model (NSHM). This version (1.0) conveys differences between 2014 NSHM fault sources and those recently released in the earthquake geology inputs for the U.S. National Seismic Hazard Model (NSHM) 2023, version 1.0 data release by Hatem et al. (2021). A notable difference between tEarthquake 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 upCompilation of geologic slip rate constraints used in 1996 - 2014 U.S. National Seismic Hazard Maps
A key input for probabilistic seismic hazard analysis (PSHA) is geologic slip rate data. Yet, no single database exists to house all geologic slip rate data used in these calculations. Here, we compile all geologic slip rates that are reportedly used in U.S. National Seismic Hazard Map (NSHM) releases from 1996, 2002, 2007, 2008, and 2014. Although a new NSHM was released in 2018, no changes were - Maps
Surface Rupture Map of the 2020 M 6.5 Monte Cristo Range earthquake, Esmeralda and Mineral counties, Nevada
The 15 May 2020, M6.5 Monte Cristo Range earthquake was the largest earthquake in Nevada in over 66 years and occurred in a sparsely populated area of western Nevada about 74 km southeast of the town of Hawthorne. The earthquake produced surface rupture distributed across a 28-km-long zone along the eastward projection of the Candelaria fault in the Mina deflection of the central Walker Lane. Post - Publications
Rapid surface rupture mapping from satellite data: The 2023 Kahramanmaraş, Turkey (Türkiye), earthquake sequence
The 6 February 2023 Kahramanmaraş, Turkey (Türkiye), earthquake sequence produced > 500 km of surface rupture primarily on the left‐lateral East Anatolian (~345 km) and Çardak (~175 km) faults. Constraining the length and magnitude of surface displacement on the causative faults is critical for loss estimates, recovery efforts, rapid identification of impacted infrastructure, and fault displacemenAuthorsNadine G. Reitman, Richard W. Briggs, William D. Barnhart, Alexandra Elise Hatem, Jessica Ann Thompson Jobe, Christopher DuRoss, Ryan D. Gold, John David Mejstrik, Camille Collett, Richard D Koehler, Sinan AkçizRapid characterization of the February 2023 Kahramanmaraş, Turkey, earthquake sequence
The 6 February 2023 Mw 7.8 Pazarcık and subsequent Mw 7.5 Elbistan earthquakes generated strong ground shaking that resulted in catastrophic human and economic loss across south‐central Türkiye and northwest Syria. The rapid characterization of the earthquakes, including their location, size, fault geometries, and slip kinematics, is critical to estimate the impact of significant seismic events.AuthorsDara Elyse Goldberg, Tuncay Taymaz, Nadine G. Reitman, Alexandra Elise Hatem, Seda Yolsal-Çevikbilen, William D. Barnhart, Tahir Serkan Irmak, David J. Wald, Taylan Öcalan, William L. Yeck, Berkan Özkan, Jessica Ann Thompson Jobe, David R. Shelly, Eric M. Thompson, Christopher DuRoss, Paul S. Earle, Richard W. Briggs, Harley M. Benz, Ceyhun Erman, Ali Hasan Doğan, Cemali AltuntaşPreface to the focus section on deformation models for the U.S. National Seismic Hazard Model
No abstract available.AuthorsFred Pollitz, Alexandra Elise Hatem, Kaj M. JohnsonWestern U.S. geologic deformation model for use in the U.S. National Seismic Hazard Model 2023
Fault geometry and slip rates are key input data for geologic deformation models, which are a fundamental component of probabilistic seismic hazard analyses (PSHAs). However, geologic sources for PSHA have traditionally been limited to faults with field‐based slip rate constraints, which results in underrepresentation of known, but partially characterized, active faults. Here, we evaluate fault geAuthorsAlexandra Elise Hatem, Nadine G. Reitman, Richard W. Briggs, Ryan D. Gold, Jessica Ann Thompson Jobe, Reed J. BurgetteWestern 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. PowersHow similar was the 1983 Mw 6.9 Borah Peak earthquake rupture to its surface-faulting predecessors along the northern Lost River fault zone (Idaho, USA)?
We excavated trenches at two paleoseismic sites bounding a trans-basin bedrock ridge (the Willow Creek Hills) along the northern Lost River fault zone to explore the uniqueness of the 1983 Mw 6.9 Borah Peak earthquake compared to its prehistoric predecessors. At the Sheep Creek site on the southernmost Warm Springs section, two earthquakes occurred at 9.8−14.0 ka (95% confidence) and 6.5−7.1 ka; eAuthorsChristopher DuRoss, Richard W. Briggs, Ryan D. Gold, Alexandra Elise Hatem, Austin John Elliott, Jaime Delano, Ivan Medina-Cascales, Harrison J. Gray, Shannon A. Mahan, Sylvia Nicovich, Zachery Lifton, Emily J. Kleber, Greg N. McDonald, Adam Hiscock, Mike Bunds, Nadine G. ReitmanSTEPS: 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. FieldField response and surface rupture characteristics of the 2020 M6.5 Monte Cristo Range earthquake, central Walker Lane, Nevada
The M 6.5 Monte Cristo Range earthquake that occurred in the central Walker Lane on 15 May 2020 was the largest earthquake in Nevada in 66 yr and resulted in a multidisciplinary scientific field response. The earthquake was the result of left‐lateral slip along largely unmapped parts of the Candelaria fault, one of a series of east–northeast‐striking faults that comprise the Mina deflection, a majAuthorsRichard D Koehler, Seth Dee, Austin John Elliott, Alexandra Elise Hatem, Alexandra Pickering, Ian Pierce, Gordon G. SeitzDocumentation of Surface Fault Rupture and Ground‐Deformation Features Produced by the 4 and 5 July 2019 Mw 6.4 and Mw 7.1 Ridgecrest Earthquake Sequence
The MwMw 6.4 and MwMw 7.1 Ridgecrest earthquake sequence occurred on 4 and 5 July 2019 within the eastern California shear zone of southern California. Both events produced extensive surface faulting and ground deformation within Indian Wells Valley and Searles Valley. In the weeks following the earthquakes, more than six dozen scientists from government, academia, and the private sector carefullyAuthorsDaniel J. Ponti, James Luke Blair, Rosa Carla M, Kate Thomas, Alexandra Pickering, Sinan Akciz, Stephen J. Angster, Jean-Philipe Avouac, Jeffrey Bachhuber, Steven Bacon, Nicolas C. Barth, S. Bennett, Kelly Blake, Stephan Bork, Benjamin A. Brooks, Thomas Bullard, Paul A. Burgess, Colin Chupik, Timothy E. Dawson, Michael DeFrisco, Jaime E. Delano, Stephen B. DeLong, James D. Dolan, Andrea Donnellan, Christopher DuRoss, Todd Ericksen, Erik Frost, Gareth J. Funning, Ryan D. Gold, Nicholas A Graehl, Carlos Gutierrez, Elizabeth Haddon, Alexandra Elise Hatem, John Helms, Janis Hernandez, Christopher S. Hitchcock, Peter Holland, Kenneth W. Hudnut, Katherine J. Kendrick, Richard D Koehler, Ozgur Kozaci, Tyler C. Ladinsky, Robert Leeper, Christopher Madugo, Maxime Mareschal, James McDonald, Devin McPhillips, Christopher Milliner, Daniel Mongovin, Alexander Morelan, Stephanie Nale, Johanna Nevitt, Matt O'Neal, Brian J. Olsen, Michael Oskin, Salena Padilla, Jason Patton, Belle E. Philibosian, Ian Pierce, Cynthia Pridmore, Nathaniel Roth, David Sandwell, Katherine Scharer, Gordon G. Seitz, Drake Singleton, Bridget Smith-Konter, Eleanor Spangler, Brian J. Swanson, Jessica Thompson Jobe, Jerome Treiman, Francesca Valencia, Joshua Vanderwal, Alana Williams, Xiaohua Xu, Judith Zachariasen, Jade Zimmerman, Robert ZinkeSurface displacement distributions for the July 2019 Ridgecrest, California earthquake ruptures
Surface rupture in the 2019 Ridgecrest, California, earthquake sequence occurred along two orthogonal cross faults and includes dominantly left‐lateral and northeast‐striking rupture in the Mw 6.4 foreshock and dominantly right‐lateral and northwest‐striking rupture in the Mw 7.1 mainshock. We present >650 field‐based, surface‐displacement observations for these ruptures and synthesize our resultsAuthorsChristopher DuRoss, Ryan D. Gold, Timothy E. Dawson, Katherine Scharer, Katherine J. Kendrick, Sinan Akciz, Stephen J. Angster, Jeffery Bachhuber, Steven Bacon, Scott E. K. Bennett, Luke Blair, Benjamin A. Brooks, Thomas Bullard, W. Paul Burgess, Colin Chupik, Michael DeFrisco, Jaime Delano, James D. Dolan, Erik Frost, Nick Graehl, Elizabeth Haddon, Alexandra Elise Hatem, Janis Hernandez, Christopher S. Hitchcock, Kennth Hudnut, Jessica Thompson Jobe, Richard D Koehler, Ozgur Kozaci, Tyler C. Ladinsky, Christopher Madugo, Devin McPhillips, Christopher Milliner, Alexander Morelan, Brian Olson, Jason Patton, Belle E. Philibosian, Alexandra J. Pickering, Ian Pierce, Daniel J. Ponti, Gordon G. Seitz, Eleanor Spangler, Brian J. Swanson, Kate Thomas, Jerome Treiman, Francesca Valencia, Alana Williams, Robert ZinkeNon-USGS Publications**
**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.
- 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 s