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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

Filter Total Items: 33

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

SSA 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 (Dut
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Natural Hazards, Earthquake Hazards, Earthquake Science Center

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 luminescence subpopu
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Natural Hazards, Earthquake Hazards, Earthquake Science Center

Geomorphic 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. Digital
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Alaska Science Center

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
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Natural Hazards, Earthquake Hazards, Earthquake Science Center

A maximum rupture model for the southern San Andreas and San Jacinto Faults California, derived from paleoseismic earthquake ages: Observations and limitations

Paleoseismic rupture histories provide spatiotemporal models of earthquake moment release needed to test numerical models and lengthen the instrumental catalog. We develop a model of the fewest and thus largest magnitude earthquakes permitted by paleoseismic data for the last 1,500 years on the southern San Andreas and San Jacinto Faults, California, USA. The largest geometric complexity appears t
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Natural Hazards, Earthquake Hazards, Earthquake Science Center

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
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Natural Hazards, Earthquake Hazards, Earthquake Science Center, Geologic Hazards Science Center, Geology, Minerals, Energy, and Geophysics Science Center

Late Quaternary slip rates on the Sierra Madre fault zone and paleoseismic evidence on the size and frequency of past ruptures

The Sierra Madre fault zone is a south-vergent, active reverse fault that accommodates shortening between basins on the northern margin of the Los Angeles region and the San Gabriel Mountains. The preservation of late Quaternary alluvial fill and fan surfaces in the hanging wall of the fault provides evidence of long-term uplift. Surface rupture from the 1971 Mw 6.6 San Fernando earthquake and evi
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Natural Hazards, Earthquake Hazards, Earthquake Science Center

Airborne lidar and electro-optical imagery along surface ruptures of the 2019 Ridgecrest earthquake sequence, Southern California

Surface rupture from the 2019 Ridgecrest earthquake sequence, initially associated with the M 6.4 foreshock, occurred on July 4 on a ~17 km long, northeast-southwest oriented, left-lateral zone of faulting. Following the M 7.1 mainshock on July 5 (local time), extensive northwest-southeast-oriented, right-lateral faulting was then also mapped along a ~50 km long zone of faults, including sub-paral
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Natural Hazards, Earthquake Hazards, Earthquake Science Center, Geologic Hazards Science Center

Late Quaternary slip rate of the Central Sierra Madre fault, southern California: Implications for slip partitioning and earthquake hazard

The Sierra Madre fault system accommodates contraction within a large restraining bend area of the San Andreas fault along the northern margin of the Los Angeles metropolitan area in Southern California. Reverse slip along this fault system during earthquakes controls growth of the San Gabriel Mountains and poses a significant seismic hazard to the region. Here, we measure the late Quaternary slip
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Natural Hazards, Earthquake Hazards, Earthquake Science Center

Preliminary report on engineering and geological effects of the July 2019 Ridgecrest earthquake sequence

The Ridgecrest Earthquake sequence included a foreshock event on July 4 2019 (M6.4) and a M7.1 mainshock event on July 5 2019. These events occurred in the Eastern California Shear Zone, near Indian Wells Valley, south of China Lake and west of Searles Valley. GEER has partnered with several organizations to collect perishable data and document the important impacts of these events, including the
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Natural Hazards, Earthquake Hazards, Earthquake Science Center, Geologic Hazards Science Center

The current unlikely earthquake hiatus at California’s transform boundary paleoseismic sites

Paleoseismic and historical earthquake records used to quantify earthquake recurrence rates can also be used to test the likelihood of seismically quiescent periods. At principal paleoseismic sites in California on the San Andreas, San Jacinto, Elsinore, and Hayward faults, no ground‐rupturing earthquake has occurred in the last 100 yr, yet this interval is about three times the average interearth
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Natural Hazards, Earthquake Hazards, Earthquake Science Center
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Exposure of the San Andreas Fault in a trench.

Back to the Future on the San Andreas Fault

Release Date: JUNE 1, 2017Investigating Past Earthquakes to Inform the FutureWhat 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...
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Natural Hazards, Earthquake Hazards
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Back to the Future on the San Andreas Fault

Release Date: JUNE 1, 2017Investigating Past Earthquakes to Inform the FutureWhat 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...
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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
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Natural Hazards, Earthquake Hazards, Geologic Hazards Science Center

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
By
Natural Hazards, Earthquake Hazards, Geologic Hazards Science Center

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