View of Glacier Bay National Park from the air.
Katherine (Kate) Scharer
Dr. Scharer holds a Ph.D. from the University of Oregon and a B.S. in Geological Sciences from the University of Washington.
Prior to coming to the USGS, she was a professor at Appalachian State University in North Carolina. Dr. Scharer studies the timing and size of pre-historic earthquakes along the San Andreas Fault and other active faults in southern California, Alaska, and the Dominican Republic. She also investigates the deformation produced by tectonic motion through a combination of field mapping, lidar analysis, and Quaternary geochronologic methods.
Science and Products
External Grants - Overview
Back to the Future on the San Andreas Fault
Earthquake geology inputs for the U.S. National Seismic Hazard Model (NSHM) 2023 (western U.S.) (ver. 3.0, December 2023)
Radiocarbon dates from the 2020 Bobcat Fire and 2013 Grand Fire, Western Transverse Ranges, California
Sediment properties, charcoal counts, and radiocarbon dates from the Pallett Creek paleoseismic site, San Gabriel Mountains, California (ver. 2.0, February 2024)
Beryllium-10 concentrations in depth profiles and surface clasts from terrace surfaces near Littlerock Creek, California
Data release for spatial and temporal analysis of geologically derived fault slip rates, Cucamonga Fault, California, USA
Earthquake geology inputs for the U.S. National Seismic Hazard Model (NSHM) 2023 (western US) (ver. 2.0, February 2022)
Earthquake geology inputs for the U.S. National Seismic Hazard Model (NSHM) 2023, version 1.0
Surface Displacement Observations of the 2019 Ridgecrest, California Earthquake Sequence
View of Glacier Bay National Park from the air.
USGS research geologist Kate Scharer with her finger on the Fairweather Fault in southeast Alaska. The magnitude 7.8 Lituya Bay earthquake caused shaking that toppled trees along the fault, which left a break in the forest shown here.
USGS research geologist Kate Scharer with her finger on the Fairweather Fault in southeast Alaska. The magnitude 7.8 Lituya Bay earthquake caused shaking that toppled trees along the fault, which left a break in the forest shown here.
The field team revisited many of the same locations geologists Don Tocher and Don Miller studied in 1958.
The field team revisited many of the same locations geologists Don Tocher and Don Miller studied in 1958.
Spatial and temporal analysis of geologic slip rates, Cucamonga Fault, California, USA: Implications for along-strike applications and multi-fault rupture
Survey of fragile geologic features and their quasi-static earthquake ground-motion constraints, southern Oregon
Observation-constrained multicycle dynamic models of the southern San Andreas and the northern San Jacinto Faults: Addressing complexity in paleoearthquake extent and recurrence with realistic 2D fault geometry
STEPS: Slip time earthquake path simulations applied to the San Andreas and Toe Jam Hill Faults to redefine geologic slip rate uncertainty
SSA task force on diversity, equity, and inclusion: Toward a changing, inclusive future in earthquake science
Late Holocene slip rate of the Mojave section of the San Andreas Fault near Palmdale, California
Holocene depositional history inferred from single-grain luminescence ages in southern California, North America
Prehistoric earthquakes on the Banning strand of the San Andreas fault, North Palm Springs, California
Geomorphic expression and slip rate of the Fairweather fault, southeast Alaska, and evidence for predecessors of the 1958 rupture
The San Andreas fault paleoseismic record at Elizabeth Lake: Why are there fewer surface-rupturing earthquakes on the Mojave section?
A revised position for the primary strand of the Pleistocene-Holocene San Andreas fault in southern California
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
STEPS: Slip Time Earthquake Path Simulations applied to the San Andreas and Toe Jam Hill faults to redefine geologic slip rate uncertainty (Matlab code)
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.Back to the Future on the San Andreas Fault
Release Date: JUNE 1, 2017 Investigating Past Earthquakes to Inform the Future What does the science say? Where does the information come from? And what does it mean? Investigating past earthquakes to inform the future. Maybe you’ve heard that the “Big One is overdue” on the San Andreas Fault. No one can predict earthquakes, so what does the science really say? Where does the information come from... - Data
Earthquake geology inputs for the U.S. National Seismic Hazard Model (NSHM) 2023 (western U.S.) (ver. 3.0, December 2023)
This Data Release contains version 3.0 of two related earthquake geology databases for use in the 2023 U.S. National Seismic Hazard Model. The databases are: 1) A fault sections database (“NSHM23_FSD_v3”), which depicts the geometry of faults capable of hosting independent earthquakes, and 2) an earthquake geology site information database (“NSHM23_EQGeoDB_v3”), which contains fault slip rate consRadiocarbon 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 of taxa preSediment 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 paleoearthquakes alongBeryllium-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 cosmogenic beryData 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 from the sampEarthquake 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 NEarthquake 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 upSurface Displacement Observations of the 2019 Ridgecrest, California Earthquake Sequence
Surface rupture associated with the 2019 Ridgecrest, California earthquake sequence includes the dominantly left-lateral and northeast-striking M6.4 rupture and dominantly right-lateral and northwest-striking M7.1 rupture. This data release includes surface-displacement observations of these ruptures made by teams of federal, state, academic, and private sector geologists between July and November - Multimedia
Glacier Bay National Park
View of Glacier Bay National Park from the air.
View of Glacier Bay National Park from the air.
Fairweather FaultUSGS research geologist Kate Scharer with her finger on the Fairweather Fault in southeast Alaska. The magnitude 7.8 Lituya Bay earthquake caused shaking that toppled trees along the fault, which left a break in the forest shown here.
USGS research geologist Kate Scharer with her finger on the Fairweather Fault in southeast Alaska. The magnitude 7.8 Lituya Bay earthquake caused shaking that toppled trees along the fault, which left a break in the forest shown here.
Alaska field team revisit Tocher's 1958 siteThe field team revisited many of the same locations geologists Don Tocher and Don Miller studied in 1958.
The field team revisited many of the same locations geologists Don Tocher and Don Miller studied in 1958.
- Publications
Filter Total Items: 43
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 large, multi-fAuthorsDevin McPhillips, Katherine ScharerSurvey 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 FGFs in southAuthorsDevin McPhillips, Katherine ScharerObservation-constrained multicycle dynamic models of the southern San Andreas and the northern San Jacinto Faults: Addressing complexity in paleoearthquake extent and recurrence with realistic 2D fault geometry
Understanding mechanical conditions that lead to complexity in earthquakes is important to seismic hazard analysis. In this study, we simulate physics-based multicycle dynamic models of the San Andreas fault (Carrizo through San Bernardino sections) and the San Jacinto fault (Claremont and Clark strands). We focus on a complex fault geometry based on the Southern California Earthquake Center CommuAuthorsDunyu Liu, Benchuan Duan, Katherine Scharer, Doug YuleSTEPS: 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. FieldSSA task force on diversity, equity, and inclusion: Toward a changing, inclusive future in earthquake science
In the United States, a wide variety of studies show that the geoscience community does not reflect the broader societal makeup (e.g., Velasco and Jaurrieta de Velasco, 2010; Dutt, 2020; Howley, 2020). In fact, only about 10% of all Science, Technology, Engineering, and Mathematics (STEM) Ph.D. degrees are awarded to people of color, although they represent more than a third of the population (DutAuthorsAaron A. Velasco, Kasey Aderhold, Richard Alfaro-Diaz, Wesley Brown, Mike Brudzinski, Margaret Fraiser, Monique M. Holt, Jim Mori, Gabriela Noriega, Katherine M. Scharer, Denise Templeton, Fabia Terra, Sherilyn Williams-StroudLate Holocene slip rate of the Mojave section of the San Andreas Fault near Palmdale, California
The geologic slip rate on the Mojave section of the San Andreas fault is poorly constrained, despite its importance for understanding earthquake hazard, apparent discrepancies between geologic and geodetic slip rates along this fault section, and long‐term fault interactions in southern California. Here, we use surficial geologic mapping, excavations, and radiocarbon and luminescence dating to quaAuthorsElaine Young, Eric Cowgill, Katherine Scharer, Emery Anderson-Merritt, Amanda Keen-Zebert, Ray J. WeldonHolocene 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 luminescence subpopuAuthorsSourav Saha, Seulgi Moon, Nathan D. Brown, Edward J. Rhodes, Katherine Scharer, Devin McPhillips, Sally F. McGill, Bryan A. CastilloPrehistoric 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 that combiAuthorsBryan A. Castillo, Sally F. McGill, Katherine Scharer, Doug Yule, Devin McPhillips, James McNeil, Sourav Saha, Nathan D. Brown, Seulgi MoonGeomorphic expression and slip rate of the Fairweather fault, southeast Alaska, and evidence for predecessors of the 1958 rupture
Active traces of the southern Fairweather fault were revealed by light detection and ranging (lidar) and show evidence for transpressional deformation between North America and the Yakutat block in southeast Alaska. We map the Holocene geomorphic expression of tectonic deformation along the southern 30 km of the Fairweather fault, which ruptured in the 1958 moment magnitude 7.8 earthquake. DigitalAuthorsRobert C. Witter, Adrian Bender, Katherine Scharer, Christopher DuRoss, Peter J. Haeussler, Richard O. LeaseThe San Andreas fault paleoseismic record at Elizabeth Lake: Why are there fewer surface-rupturing earthquakes on the Mojave section?
The structural complexity of active faults and the stress release history along the fault system may exert control on the locus and extent of individual earthquake ruptures. Fault bends, in particular, are often invoked as a possible mechanism for terminating earthquake ruptures. However, there are few records available to examine how these factors may influence the along‐fault recurrence of earthAuthorsSean Bemis, Katherine Scharer, James D. DolanA revised position for the primary strand of the Pleistocene-Holocene San Andreas fault in southern California
The San Andreas fault has the highest calculated time-dependent probability for large-magnitude earthquakes in southern California. However, where the fault is multistranded east of the Los Angeles metropolitan area, it has been uncertain which strand has the fastest slip rate and, therefore, which has the highest probability of a destructive earthquake. Reconstruction of offset Pleistocene-HoloceAuthorsKim Blisniuk, Katherine Scharer, Warren Sharp, Roland Burgmann, Colin Amos, Michael RymerDocumentation 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 Zinke - 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