Devin McPhillips, PhD
As an earthquake geologist, I investigate fault systems, fault activity, and ground shaking intensity. I am particularly interested in records of past earthquakes that are preserved in the landscape. My research methods include field observation, geochronology, and quantitative analysis. My goals are to quantify seismic hazard and reduce risk.
Professional Experience
Research Geologist: USGS-ESC, 2023-present
Geologist: USGS-ESC, 2016-2023
Research Associate: Syracuse University, 2013-2105
NSF Postdoctoral Fellow: University of Vermont, 2011-2013
Education and Certifications
PhD: Yale University, 2011
BA: Carleton College, 2003
Science and Products
Precariously balanced rock data from northern New York and Vermont, USA
This work describes observations of boulders and their pedestals at five sites in New York and Vermont, which are used to calculate scaling factors for the 2023 time-independent National Seismic Hazard Model site-specific hazard curves (Petersen, M.D., Shumway, A.M., Powers, P.M., Field, E.H., Moschetti, M.P., Jaiswal, K.S., Milner, K.R., Rezaeian, S., Frankel, A.D., Llenos, A.L. and...
Data Release for the 2023 U.S. 50-State National Seismic Hazard Model - Overview
This data release contains data sets associated with the 2023 50-State National Seismic Hazard Model Update. The 2023 50-State National Seimsic Hazard Model (NSHM) Update includes an update to the NSHMs for the conterminous U.S (CONUS, last updated in 2018), Alaska (AK, last updated in 2007), and Hawaii (last updated in 2001). Data sets include inputs like seismicity catalogs used as...
Data release for fault activity in the San Gabriel Mountains, USA: insights from landscape morphometrics, erosion rates, and fault-slip rates (ver. 2.0, November 2023)
This report summarizes geomorphic data and analysis from the range front and interior of the San Gabriel Mountains, California, USA. For catchment-average erosion rates, we describe the methodology used to collect samples of detrital sediment, determine concentrations of cosmogenic beryllium-10 in purified quartz isolated from the samples, and use those nuclide concentrations to...
Radiocarbon dates from the 2020 Bobcat Fire and 2013 Grand Fire, Western Transverse Ranges, California
This data release provides radiocarbon data for burned plant material collected from deposits following two wildfires in southern California. For the 2020 Bobcat Fire we collected deposits in five stream channels within the Pallett Creek drainage in 2021. For the 2013 Grand Fire near Frazier Mountain, we sampled from two shallow pits excavated into alluvium deposited in 2014. The types...
Sediment properties, charcoal counts, and radiocarbon dates from the Pallett Creek paleoseismic site, San Gabriel Mountains, California (ver. 2.0, February 2024)
This data release provides geochemical, sedimentological, and geochronological data from interbedded fluvial and marsh deposits and radiocarbon dates of the section spanning the last 1500 years from the Pallett Creek paleoseismic site, California. The samples were collected to support paleoenvironmental reconstruction of the site and refine several previous investigations of...
Beryllium-10 concentrations in depth profiles and surface clasts from terrace surfaces near Littlerock Creek, California
This report summarizes the age-dating results from four terrace surfaces of the Littlerock Creek (map units T3g, T3c, T2, and T1c) that record cumulative strike-slip displacements ranging from 470 to 1080 meters along the Mojave section of the San Andreas Fault. Within this report are detailed the methodology used to collect samples of rock and sediment, determine concentrations of...
Remote survey of fragile geologic features for use as earthquake ground motion constraints, Oregon and Washington, USA
Fragile geologic features (FGFs) are elements of the landscape that are vulnerable to destruction during sufficiently strong earthquake ground shaking. As result, the observation of extant FGFs on the landscape may constrain the maximum intensity of past earthquake shaking. McPhillips and Scharer (2022, Survey of fragile geologic features and their quasi-static earthquake ground motion...
Data release for spatial and temporal analysis of geologically derived fault slip rates, Cucamonga Fault, California, USA
This report summarizes the age-dating results from two alluvial fan surfaces (map units Qyf2 and Qyf3) that are broken by strands of the Cucamonga Fault, in southern California, at Day Canyon and Etiwanda Canyon. Within this report are detailed the methodology used to collect samples of rock and sediment, determine concentrations of cosmogenic beryllium-10 in purified quartz isolated...
Updated Compilation of VS30 Data for the United States
VS30, the time-averaged shear-wave velocity (VS) to a depth of 30 meters, is a key index adopted by the earthquake engineering community to account for seismic site conditions. VS30 is typically based on geophysical measurements of VS derived from invasive and noninvasive techniques at sites of interest. Owing to cost considerations, as well as logistical and environmental concerns, VS30...
Filter Total Items: 22
Precariously balanced rocks in northern New York and Vermont, U.S.A.: Ground-motion constraints and implications for fault sources
Precariously balanced rocks (PBRs) and other fragile geologic features have the potential to constrain the maximum intensity of earthquake ground shaking over millennia. Such constraints may be particularly useful in the eastern United States (U.S.), where few earthquake‐source faults are reliably identified, and moderate earthquakes can be felt at great distances due to low seismic...
Authors
Devin McPhillips, Thomas L. Pratt
Inbuilt age, residence time, and inherited age from radiocarbon dates of modern fires and late Holocene deposits, Western Transverse Ranges, California
Radiocarbon dates of sedimentary deposits include the elapsed time between formation of the organic material and deposition at the sample site, known as the inherited age. Long inherited ages reduce the accuracy of estimates of the timing of depositional events used to infer paleoclimate change, fire histories, and paleoearthquake timing. An inherited age distribution combines the...
Authors
Katherine M. Scharer, Devin McPhillips, Jenifer Amy Leidelmeijer, Matthew E. Kirby
Fault activity in the San Gabriel Mountains, southern California, USA: Insights from landscape morphometrics, erosion rates, and fault-slip rates
Many studies use landscape form to determine spatial patterns of tectonic deformation, and these are particularly effective when paired with independent measures of rock uplift and erosion. Here, we use morphometric analyses and 10Be catchment-averaged erosion rates, together with reverse slip rates from the Sierra Madre−Cucamonga fault zone, to reveal patterns in uplift, erosion, and...
Authors
Andrew Meredith, Devin McPhillips
The 2023 US 50-State National Seismic Hazard Model: Overview and implications
The US National Seismic Hazard Model (NSHM) was updated in 2023 for all 50 states using new science on seismicity, fault ruptures, ground motions, and probabilistic techniques to produce a standard of practice for public policy and other engineering applications (defined for return periods greater than ∼475 or less than ∼10,000 years). Changes in 2023 time-independent seismic hazard...
Authors
Mark D. Petersen, Allison Shumway, Peter M. Powers, Ned Field, Morgan P. Moschetti, Kishor S. Jaiswal, Kevin R. Milner, Sanaz Rezaeian, Arthur Frankel, Andrea L. Llenos, Andrew J. Michael, Jason M. Altekruse, Sean Kamran Ahdi, Kyle Withers, Charles Mueller, Yuehua Zeng, Robert Edward Chase, Leah Marschall Salditch, Nico Luco, Kenneth S. Rukstales, Julie Herrick, Demi Leafar Girot, Brad T. Aagaard, Adrian M. Bender, Michael L. Blanpied, Richard W. Briggs, Oliver S. Boyd, Brandon Clayton, Christopher DuRoss, Eileen Evans, Peter J. Haeussler, Alexandra Elise Hatem, Kirstie Lafon Haynie, Elizabeth H. Hearn, Kaj M. Johnson, Zachary Alan Kortum, N. Simon Kwong, Andrew James Makdisi, Henry (Ben) Mason, Daniel McNamara, Devin McPhillips, Paul G. Okubo, Morgan T. Page, Frederick Pollitz, Justin L. Rubinstein, Bruce E. Shaw, Zheng-Kang Shen, Brian Shiro, James Andrew Smith, William J. Stephenson, Eric M. Thompson, Jessica Ann Thompson Jobe, Erin Wirth, Robert Witter
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...
Authors
Ned Field, Kevin R. Milner, Alexandra Elise Hatem, Peter M. Powers, Frederick Pollitz, Andrea L. Llenos, Yuehua Zeng, Kaj M. Johnson, Bruce E. Shaw, Devin McPhillips, Jessica Ann Thompson Jobe, Allison Shumway, Andrew J. Michael, Zheng-Kang Shen, Eileen Evans, Elizabeth H. Hearn, Charles Mueller, Arthur Frankel, Mark D. Petersen, Christopher DuRoss, Richard W. Briggs, Morgan T. Page, Justin L. Rubinstein, Julie Herrick
The Mojave section of the San Andreas fault (California), 1: Shaping the terrace stratigraphy of Littlerock Creek through the competition between rapid strike-slip faulting and lateral stream erosion over the last 40ka.
To determine the post-40 ka slip-rate along the Mojave section of the San Andreas Fault (MSAF) we re-analyze the sedimentary record preserved where Little Rock (LR) Creek flows across the fault. At this location, interaction between the northeast-flowing stream and right-lateral fault has resulted in the abandonment and preservation of 11 strath terraces and one paleo-floodplain in the...
Authors
Adrien Moulin, Eric S. Cowgill, Katherine M. Scharer, Devin McPhillips, Arjun Heimsath
Spatial and temporal analysis of geologic slip rates, Cucamonga Fault, California, USA: Implications for along-strike applications and multi-fault rupture
To constrain fault processes and hazard, fault slip rates may be extrapolated over different fault lengths or time intervals. Here, we investigate slip rates for the Cucamonga Fault (CF). The CF is located at the junction of the Transverse Range fault system with the San Andreas and San Jacinto Faults, and it is hypothesized to connect with these faults, promoting the propagation of...
Authors
Devin McPhillips, Katherine M. Scharer
Survey of fragile geologic features and their quasi-static earthquake ground-motion constraints, southern Oregon
Fragile geologic features (FGFs), which are extant on the landscape but vulnerable to earthquake ground shaking, may provide geological constraints on the intensity of prior shaking. These empirical constraints are particularly important in regions such as the Pacific Northwest that have not experienced a megathrust earthquake in written history. Here, we describe our field survey of...
Authors
Devin McPhillips, Katherine M. Scharer
Revised earthquake recurrence intervals in California, USA: New paleoseismic sites and application of event likelihoods
Recurrence intervals for ground rupturing earthquakes are critical data for assessing seismic hazard. Recurrence intervals are presented here for 38 paleoseismic sites in California. Eleven of these include new or updated data; the remainder use data previously included in the Unified California Earthquake Rupture Forecast Version 3 (UCERF3). The methods and results are consistent with...
Authors
Devin McPhillips
Toppling of a Trona Pinnacles Spire following the M5.5 RidgecrestaAftershock of June 2020
The 2019 Mw 7.1 Ridgecrest California earthquake rupture passed within 4 km of the Trona Pinnacles, a large group of tufa rock pillars. Reconnaissance following the Ridgecrest mainshock documented fresh damage to several of the Pinnacles. Repeated aerial photogrammetric surveys also documented damage during subsequent aftershocks. Here, we describe the photogrammetric data with emphasis...
Authors
Andrea Donnellan, Joaquin Garcia-Suarez, Devin McPhillips, Domniki Asimaki, Christine A. Goulet, Xiaofeng Meng, Savannah Devine, Gregory Lyzanga
Holocene depositional history inferred from single-grain luminescence ages in southern California, North America
Significant sediment flux and deposition in a sedimentary system are influenced by climate changes, tectonics, lithology, and the sedimentary system's internal dynamics. Identifying the timing of depositional periods from stratigraphic records is a first step to critically evaluate the controls of sediment flux and deposition. Here, we show that ages of single-grain K-feldspar...
Authors
Sourav Saha, Seulgi Moon, Nathan D. Brown, Edward J. Rhodes, Katherine M. Scharer, Devin McPhillips, Sally F. McGill, Bryan A. Castillo
Prehistoric earthquakes on the Banning strand of the San Andreas fault, North Palm Springs, California
We studied a paleoseismic trench excavated in 2017 across the Banning strand of the San Andreas fault and herein provide the first detailed record of ground-breaking earthquakes on this important fault in Southern California. The trench exposed an ~40-m-wide fault zone cutting through alluvial sand, gravel, silt, and clay deposits. We evaluated the paleoseismic record using a new metric...
Authors
Bryan A. Castillo, Sally F. McGill, Katherine M. Scharer, Doug Yule, Devin McPhillips, James McNeil, Sourav Saha, Nathan D. Brown, Seulgi Moon
Science and Products
Precariously balanced rock data from northern New York and Vermont, USA
This work describes observations of boulders and their pedestals at five sites in New York and Vermont, which are used to calculate scaling factors for the 2023 time-independent National Seismic Hazard Model site-specific hazard curves (Petersen, M.D., Shumway, A.M., Powers, P.M., Field, E.H., Moschetti, M.P., Jaiswal, K.S., Milner, K.R., Rezaeian, S., Frankel, A.D., Llenos, A.L. and...
Data Release for the 2023 U.S. 50-State National Seismic Hazard Model - Overview
This data release contains data sets associated with the 2023 50-State National Seismic Hazard Model Update. The 2023 50-State National Seimsic Hazard Model (NSHM) Update includes an update to the NSHMs for the conterminous U.S (CONUS, last updated in 2018), Alaska (AK, last updated in 2007), and Hawaii (last updated in 2001). Data sets include inputs like seismicity catalogs used as...
Data release for fault activity in the San Gabriel Mountains, USA: insights from landscape morphometrics, erosion rates, and fault-slip rates (ver. 2.0, November 2023)
This report summarizes geomorphic data and analysis from the range front and interior of the San Gabriel Mountains, California, USA. For catchment-average erosion rates, we describe the methodology used to collect samples of detrital sediment, determine concentrations of cosmogenic beryllium-10 in purified quartz isolated from the samples, and use those nuclide concentrations to...
Radiocarbon dates from the 2020 Bobcat Fire and 2013 Grand Fire, Western Transverse Ranges, California
This data release provides radiocarbon data for burned plant material collected from deposits following two wildfires in southern California. For the 2020 Bobcat Fire we collected deposits in five stream channels within the Pallett Creek drainage in 2021. For the 2013 Grand Fire near Frazier Mountain, we sampled from two shallow pits excavated into alluvium deposited in 2014. The types...
Sediment properties, charcoal counts, and radiocarbon dates from the Pallett Creek paleoseismic site, San Gabriel Mountains, California (ver. 2.0, February 2024)
This data release provides geochemical, sedimentological, and geochronological data from interbedded fluvial and marsh deposits and radiocarbon dates of the section spanning the last 1500 years from the Pallett Creek paleoseismic site, California. The samples were collected to support paleoenvironmental reconstruction of the site and refine several previous investigations of...
Beryllium-10 concentrations in depth profiles and surface clasts from terrace surfaces near Littlerock Creek, California
This report summarizes the age-dating results from four terrace surfaces of the Littlerock Creek (map units T3g, T3c, T2, and T1c) that record cumulative strike-slip displacements ranging from 470 to 1080 meters along the Mojave section of the San Andreas Fault. Within this report are detailed the methodology used to collect samples of rock and sediment, determine concentrations of...
Remote survey of fragile geologic features for use as earthquake ground motion constraints, Oregon and Washington, USA
Fragile geologic features (FGFs) are elements of the landscape that are vulnerable to destruction during sufficiently strong earthquake ground shaking. As result, the observation of extant FGFs on the landscape may constrain the maximum intensity of past earthquake shaking. McPhillips and Scharer (2022, Survey of fragile geologic features and their quasi-static earthquake ground motion...
Data release for spatial and temporal analysis of geologically derived fault slip rates, Cucamonga Fault, California, USA
This report summarizes the age-dating results from two alluvial fan surfaces (map units Qyf2 and Qyf3) that are broken by strands of the Cucamonga Fault, in southern California, at Day Canyon and Etiwanda Canyon. Within this report are detailed the methodology used to collect samples of rock and sediment, determine concentrations of cosmogenic beryllium-10 in purified quartz isolated...
Updated Compilation of VS30 Data for the United States
VS30, the time-averaged shear-wave velocity (VS) to a depth of 30 meters, is a key index adopted by the earthquake engineering community to account for seismic site conditions. VS30 is typically based on geophysical measurements of VS derived from invasive and noninvasive techniques at sites of interest. Owing to cost considerations, as well as logistical and environmental concerns, VS30...
Filter Total Items: 22
Precariously balanced rocks in northern New York and Vermont, U.S.A.: Ground-motion constraints and implications for fault sources
Precariously balanced rocks (PBRs) and other fragile geologic features have the potential to constrain the maximum intensity of earthquake ground shaking over millennia. Such constraints may be particularly useful in the eastern United States (U.S.), where few earthquake‐source faults are reliably identified, and moderate earthquakes can be felt at great distances due to low seismic...
Authors
Devin McPhillips, Thomas L. Pratt
Inbuilt age, residence time, and inherited age from radiocarbon dates of modern fires and late Holocene deposits, Western Transverse Ranges, California
Radiocarbon dates of sedimentary deposits include the elapsed time between formation of the organic material and deposition at the sample site, known as the inherited age. Long inherited ages reduce the accuracy of estimates of the timing of depositional events used to infer paleoclimate change, fire histories, and paleoearthquake timing. An inherited age distribution combines the...
Authors
Katherine M. Scharer, Devin McPhillips, Jenifer Amy Leidelmeijer, Matthew E. Kirby
Fault activity in the San Gabriel Mountains, southern California, USA: Insights from landscape morphometrics, erosion rates, and fault-slip rates
Many studies use landscape form to determine spatial patterns of tectonic deformation, and these are particularly effective when paired with independent measures of rock uplift and erosion. Here, we use morphometric analyses and 10Be catchment-averaged erosion rates, together with reverse slip rates from the Sierra Madre−Cucamonga fault zone, to reveal patterns in uplift, erosion, and...
Authors
Andrew Meredith, Devin McPhillips
The 2023 US 50-State National Seismic Hazard Model: Overview and implications
The US National Seismic Hazard Model (NSHM) was updated in 2023 for all 50 states using new science on seismicity, fault ruptures, ground motions, and probabilistic techniques to produce a standard of practice for public policy and other engineering applications (defined for return periods greater than ∼475 or less than ∼10,000 years). Changes in 2023 time-independent seismic hazard...
Authors
Mark D. Petersen, Allison Shumway, Peter M. Powers, Ned Field, Morgan P. Moschetti, Kishor S. Jaiswal, Kevin R. Milner, Sanaz Rezaeian, Arthur Frankel, Andrea L. Llenos, Andrew J. Michael, Jason M. Altekruse, Sean Kamran Ahdi, Kyle Withers, Charles Mueller, Yuehua Zeng, Robert Edward Chase, Leah Marschall Salditch, Nico Luco, Kenneth S. Rukstales, Julie Herrick, Demi Leafar Girot, Brad T. Aagaard, Adrian M. Bender, Michael L. Blanpied, Richard W. Briggs, Oliver S. Boyd, Brandon Clayton, Christopher DuRoss, Eileen Evans, Peter J. Haeussler, Alexandra Elise Hatem, Kirstie Lafon Haynie, Elizabeth H. Hearn, Kaj M. Johnson, Zachary Alan Kortum, N. Simon Kwong, Andrew James Makdisi, Henry (Ben) Mason, Daniel McNamara, Devin McPhillips, Paul G. Okubo, Morgan T. Page, Frederick Pollitz, Justin L. Rubinstein, Bruce E. Shaw, Zheng-Kang Shen, Brian Shiro, James Andrew Smith, William J. Stephenson, Eric M. Thompson, Jessica Ann Thompson Jobe, Erin Wirth, Robert Witter
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...
Authors
Ned Field, Kevin R. Milner, Alexandra Elise Hatem, Peter M. Powers, Frederick Pollitz, Andrea L. Llenos, Yuehua Zeng, Kaj M. Johnson, Bruce E. Shaw, Devin McPhillips, Jessica Ann Thompson Jobe, Allison Shumway, Andrew J. Michael, Zheng-Kang Shen, Eileen Evans, Elizabeth H. Hearn, Charles Mueller, Arthur Frankel, Mark D. Petersen, Christopher DuRoss, Richard W. Briggs, Morgan T. Page, Justin L. Rubinstein, Julie Herrick
The Mojave section of the San Andreas fault (California), 1: Shaping the terrace stratigraphy of Littlerock Creek through the competition between rapid strike-slip faulting and lateral stream erosion over the last 40ka.
To determine the post-40 ka slip-rate along the Mojave section of the San Andreas Fault (MSAF) we re-analyze the sedimentary record preserved where Little Rock (LR) Creek flows across the fault. At this location, interaction between the northeast-flowing stream and right-lateral fault has resulted in the abandonment and preservation of 11 strath terraces and one paleo-floodplain in the...
Authors
Adrien Moulin, Eric S. Cowgill, Katherine M. Scharer, Devin McPhillips, Arjun Heimsath
Spatial and temporal analysis of geologic slip rates, Cucamonga Fault, California, USA: Implications for along-strike applications and multi-fault rupture
To constrain fault processes and hazard, fault slip rates may be extrapolated over different fault lengths or time intervals. Here, we investigate slip rates for the Cucamonga Fault (CF). The CF is located at the junction of the Transverse Range fault system with the San Andreas and San Jacinto Faults, and it is hypothesized to connect with these faults, promoting the propagation of...
Authors
Devin McPhillips, Katherine M. Scharer
Survey of fragile geologic features and their quasi-static earthquake ground-motion constraints, southern Oregon
Fragile geologic features (FGFs), which are extant on the landscape but vulnerable to earthquake ground shaking, may provide geological constraints on the intensity of prior shaking. These empirical constraints are particularly important in regions such as the Pacific Northwest that have not experienced a megathrust earthquake in written history. Here, we describe our field survey of...
Authors
Devin McPhillips, Katherine M. Scharer
Revised earthquake recurrence intervals in California, USA: New paleoseismic sites and application of event likelihoods
Recurrence intervals for ground rupturing earthquakes are critical data for assessing seismic hazard. Recurrence intervals are presented here for 38 paleoseismic sites in California. Eleven of these include new or updated data; the remainder use data previously included in the Unified California Earthquake Rupture Forecast Version 3 (UCERF3). The methods and results are consistent with...
Authors
Devin McPhillips
Toppling of a Trona Pinnacles Spire following the M5.5 RidgecrestaAftershock of June 2020
The 2019 Mw 7.1 Ridgecrest California earthquake rupture passed within 4 km of the Trona Pinnacles, a large group of tufa rock pillars. Reconnaissance following the Ridgecrest mainshock documented fresh damage to several of the Pinnacles. Repeated aerial photogrammetric surveys also documented damage during subsequent aftershocks. Here, we describe the photogrammetric data with emphasis...
Authors
Andrea Donnellan, Joaquin Garcia-Suarez, Devin McPhillips, Domniki Asimaki, Christine A. Goulet, Xiaofeng Meng, Savannah Devine, Gregory Lyzanga
Holocene depositional history inferred from single-grain luminescence ages in southern California, North America
Significant sediment flux and deposition in a sedimentary system are influenced by climate changes, tectonics, lithology, and the sedimentary system's internal dynamics. Identifying the timing of depositional periods from stratigraphic records is a first step to critically evaluate the controls of sediment flux and deposition. Here, we show that ages of single-grain K-feldspar...
Authors
Sourav Saha, Seulgi Moon, Nathan D. Brown, Edward J. Rhodes, Katherine M. Scharer, Devin McPhillips, Sally F. McGill, Bryan A. Castillo
Prehistoric earthquakes on the Banning strand of the San Andreas fault, North Palm Springs, California
We studied a paleoseismic trench excavated in 2017 across the Banning strand of the San Andreas fault and herein provide the first detailed record of ground-breaking earthquakes on this important fault in Southern California. The trench exposed an ~40-m-wide fault zone cutting through alluvial sand, gravel, silt, and clay deposits. We evaluated the paleoseismic record using a new metric...
Authors
Bryan A. Castillo, Sally F. McGill, Katherine M. Scharer, Doug Yule, Devin McPhillips, James McNeil, Sourav Saha, Nathan D. Brown, Seulgi Moon