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: 43
Evidence for coseismic subsidence events in a southern California coastal saltmarsh
Paleoenvironmental records from a southern California coastal saltmarsh reveal evidence for repeated late Holocene coseismic subsidence events. Field analysis of sediment gouge cores established discrete lithostratigraphic units extend across the wetland. Detailed sediment analyses reveal abrupt changes in lithology, percent total organic matter, grain size, and magnetic susceptibility. Microfossi
Authors
Robert Leeper, Brady P. Rhodes, Matthew E. Kirby, Katherine M. Scharer, Joseph A. Carlin, Eileen Hemphill-Haley, Simona Avnaim-Katav, Glen M. MacDonald, Scott W. Starratt, Angela Aranda
Ground-rupturing earthquakes on the northern Big Bend of the San Andreas Fault, California, 800 A.D. to Present
Paleoseismic data on the timing of ground-rupturing earthquakes constrain the recurrence behavior of active faults and can provide insight on the rupture history of a fault if earthquakes dated at neighboring sites overlap in age and are considered correlative. This study presents the evidence and ages for 11 earthquakes that occurred along the Big Bend section of the southern San Andreas Fault at
Authors
Katherine M. Scharer, Ray J. Weldon, Glenn Biasi, Ashley Streig, Thomas E. Fumal
Late Quaternary offset of alluvial fan surfaces along the Central Sierra Madre Fault, southern California
The Sierra Madre Fault is a reverse fault system along the southern flank of the San Gabriel Mountains near Los Angeles, California. This study focuses on the Central Sierra Madre Fault (CSMF) in an effort to provide numeric dating on surfaces with ages previously estimated from soil development alone. We have refined previous geomorphic mapping conducted in the western portion of the CSMF near Pa
Authors
Reed J. Burgette, Austin Hanson, Katherine M. Scharer, Nikolas Midttun
Does paleoseismology forecast the historic rates of large earthquakes on the San Andreas fault system?
The 98-year open interval since the most recent ground-rupturing earthquake in the greater San Andreas boundary fault system would not be predicted by the quasi-periodic recurrence statistics from paleoseismic data. We examine whether the current hiatus could be explained by uncertainties in earthquake dating. Using seven independent paleoseismic records, 100 year intervals may have occurred circ
Authors
Glenn Biasi, Katherine M. Scharer, Ray J. Weldon, Timothy E. Dawson
Testing geomorphology-derived rupture histories against the paleoseismic record of the southern San Andreas fault
Evidence for the 340-km-long Fort Tejon earthquake of 1857 is found at each of the high-resolution paleoseismic sites on the southern San Andreas Fault. Using trenching data from these sites, we find that the assemblage of dated paleoearthquakes recurs quasi-periodically (coefficient of variation, COV, of 0.6, Biasi, 2013) and requires ~80% of ruptures were shorter than the 1857 rupture with an av
Authors
Katherine M. Scharer, Ray J. Weldon, Sean Bemis
Earthquake geology and paleoseismology of major strands of the San Andreas fault system
The San Andreas fault system in California is one of the best-studied faults in the world, both in terms of the long-term geologic history and paleoseismic study of past surface ruptures. In this paper, we focus on the Quaternary to historic data that have been collected from the major strands of the San Andreas fault system, both on the San Andreas Fault itself, and the major subparallel strands
Authors
Thomas Rockwell, Katherine M. Scharer, Timothy E. Dawson
The Elizabeth Lake paleoseismic site: Rupture pattern constraints for the past ~800 years for the Mojave section of the south-central San Andreas Fault
The southern San Andreas Fault in California has hosted two historic surface-rupturing earthquakes, the ~M7 1812 Wrightwood earthquake and the ~M7.9 1857 Fort Tejon earthquake (e.g., Sieh, 1978; Jacoby et al., 1988). Numerous paleoseismic studies have established chronologies of historic and prehistoric earthquakes at sites along the full length of the 1857 rupture (e.g., Sieh, 1978; Scharer et al
Authors
Sean Bemis, Katherine M. Scharer, James F. Dolan, Ed Rhodes
Validation of meter-scale surface faulting offset measurements from high-resolution topographic data
Studies of active fault zones have flourished with the availability of high-resolution topographic data, particularly where airborne light detection and ranging (lidar) and structure from motion (SfM) data sets provide a means to remotely analyze submeter-scale fault geomorphology. To determine surface offset at a point along a strike-slip earthquake rupture, geomorphic features (e.g., stream chan
Authors
Barrett Salisbury, D.E. Haddad, T. K. Rockwell, R. Arrowsmith, C. Madugo, O. Zielke, Katherine M. Scharer
Photomosaics and event evidence from the Frazier Mountain paleoseismic site, trench 1, cuts 5–24, San Andreas Fault Zone, southern California (2010–2012)
The Frazier Mountain paleoseismic site is located within the northern Big Bend of the southern San Andreas Fault (lat 34.8122° N., lon 118.9034° W.), in a small structural basin formed by the fault (fig. 1). The site has been the focus of over a decade of paleoseismic study due to high stratigraphic resolution and abundant dateable material. Trench 1 (T1) was initially excavated as a 50-m long, fa
Authors
Katherine M. Scharer, Tom E. Fumal, Ray J. Weldon, Ashley R. Streig
The Mw6.0 24 August 2014 South Napa earthquake
The Mw 6.0 South Napa earthquake, which occurred at 10:20 UTC 24 August 2014 was the largest earthquake to strike the greater San Francisco Bay area since the Mw 6.9 1989 Loma Prieta earthquake. The rupture from this right‐lateral earthquake propagated mostly unilaterally to the north and up‐dip, directing the strongest shaking toward the city of Napa, where peak ground accelerations (PGAs) betwee
Authors
Thomas M. Brocher, Annemarie S. Baltay, Jeanne L. Hardebeck, Fred F. Pollitz, Jessica R. Murray, Andrea L. Llenos, David P. Schwartz, J. Luke Blair, Daniel J. Ponti, James J. Lienkaemper, Victoria E. Langenheim, Timothy E. Dawson, Kenneth W. Hudnut, David R. Shelly, Douglas S. Dreger, John Boatwright, Brad T. Aagaard, David J. Wald, Richard M. Allen, William D. Barnhart, Keith L. Knudsen, Benjamin A. Brooks, Katherine M. Scharer
Rapid mapping of ultrafine fault zone topography with structure from motion
Structure from Motion (SfM) generates high-resolution topography and coregistered texture (color) from an unstructured set of overlapping photographs taken from varying viewpoints, overcoming many of the cost, time, and logistical limitations of Light Detection and Ranging (LiDAR) and other topographic surveying methods. This paper provides the first investigation of SfM as a tool for mapping faul
Authors
Kendra Johnson, Edwin Nissen, Srikanth Saripalli, J. Ramón Arrowsmith, Patrick McGarey, Katherine M. Scharer, Patrick Williams, Kimberly Blisniuk
Paleoearthquakes at Frazier Mountain, California delimit extent and frequency of past San Andreas Fault ruptures along 1857 trace
Large earthquakes are infrequent along a single fault, and therefore historic, well-characterized earthquakes exert a strong influence on fault behavior models. This is true of the 1857 Fort Tejon earthquake (estimated M7.7–7.9) on the southern San Andreas Fault (SSAF), but an outstanding question is whether the 330 km long rupture was typical. New paleoseismic data for six to seven ground-rupturi
Authors
Katherine M. Scharer, Ray Weldon, Ashley Streig, Thomas Fumal
Science and Products
Filter Total Items: 43
Evidence for coseismic subsidence events in a southern California coastal saltmarsh
Paleoenvironmental records from a southern California coastal saltmarsh reveal evidence for repeated late Holocene coseismic subsidence events. Field analysis of sediment gouge cores established discrete lithostratigraphic units extend across the wetland. Detailed sediment analyses reveal abrupt changes in lithology, percent total organic matter, grain size, and magnetic susceptibility. Microfossi
Authors
Robert Leeper, Brady P. Rhodes, Matthew E. Kirby, Katherine M. Scharer, Joseph A. Carlin, Eileen Hemphill-Haley, Simona Avnaim-Katav, Glen M. MacDonald, Scott W. Starratt, Angela Aranda
Ground-rupturing earthquakes on the northern Big Bend of the San Andreas Fault, California, 800 A.D. to Present
Paleoseismic data on the timing of ground-rupturing earthquakes constrain the recurrence behavior of active faults and can provide insight on the rupture history of a fault if earthquakes dated at neighboring sites overlap in age and are considered correlative. This study presents the evidence and ages for 11 earthquakes that occurred along the Big Bend section of the southern San Andreas Fault at
Authors
Katherine M. Scharer, Ray J. Weldon, Glenn Biasi, Ashley Streig, Thomas E. Fumal
Late Quaternary offset of alluvial fan surfaces along the Central Sierra Madre Fault, southern California
The Sierra Madre Fault is a reverse fault system along the southern flank of the San Gabriel Mountains near Los Angeles, California. This study focuses on the Central Sierra Madre Fault (CSMF) in an effort to provide numeric dating on surfaces with ages previously estimated from soil development alone. We have refined previous geomorphic mapping conducted in the western portion of the CSMF near Pa
Authors
Reed J. Burgette, Austin Hanson, Katherine M. Scharer, Nikolas Midttun
Does paleoseismology forecast the historic rates of large earthquakes on the San Andreas fault system?
The 98-year open interval since the most recent ground-rupturing earthquake in the greater San Andreas boundary fault system would not be predicted by the quasi-periodic recurrence statistics from paleoseismic data. We examine whether the current hiatus could be explained by uncertainties in earthquake dating. Using seven independent paleoseismic records, 100 year intervals may have occurred circ
Authors
Glenn Biasi, Katherine M. Scharer, Ray J. Weldon, Timothy E. Dawson
Testing geomorphology-derived rupture histories against the paleoseismic record of the southern San Andreas fault
Evidence for the 340-km-long Fort Tejon earthquake of 1857 is found at each of the high-resolution paleoseismic sites on the southern San Andreas Fault. Using trenching data from these sites, we find that the assemblage of dated paleoearthquakes recurs quasi-periodically (coefficient of variation, COV, of 0.6, Biasi, 2013) and requires ~80% of ruptures were shorter than the 1857 rupture with an av
Authors
Katherine M. Scharer, Ray J. Weldon, Sean Bemis
Earthquake geology and paleoseismology of major strands of the San Andreas fault system
The San Andreas fault system in California is one of the best-studied faults in the world, both in terms of the long-term geologic history and paleoseismic study of past surface ruptures. In this paper, we focus on the Quaternary to historic data that have been collected from the major strands of the San Andreas fault system, both on the San Andreas Fault itself, and the major subparallel strands
Authors
Thomas Rockwell, Katherine M. Scharer, Timothy E. Dawson
The Elizabeth Lake paleoseismic site: Rupture pattern constraints for the past ~800 years for the Mojave section of the south-central San Andreas Fault
The southern San Andreas Fault in California has hosted two historic surface-rupturing earthquakes, the ~M7 1812 Wrightwood earthquake and the ~M7.9 1857 Fort Tejon earthquake (e.g., Sieh, 1978; Jacoby et al., 1988). Numerous paleoseismic studies have established chronologies of historic and prehistoric earthquakes at sites along the full length of the 1857 rupture (e.g., Sieh, 1978; Scharer et al
Authors
Sean Bemis, Katherine M. Scharer, James F. Dolan, Ed Rhodes
Validation of meter-scale surface faulting offset measurements from high-resolution topographic data
Studies of active fault zones have flourished with the availability of high-resolution topographic data, particularly where airborne light detection and ranging (lidar) and structure from motion (SfM) data sets provide a means to remotely analyze submeter-scale fault geomorphology. To determine surface offset at a point along a strike-slip earthquake rupture, geomorphic features (e.g., stream chan
Authors
Barrett Salisbury, D.E. Haddad, T. K. Rockwell, R. Arrowsmith, C. Madugo, O. Zielke, Katherine M. Scharer
Photomosaics and event evidence from the Frazier Mountain paleoseismic site, trench 1, cuts 5–24, San Andreas Fault Zone, southern California (2010–2012)
The Frazier Mountain paleoseismic site is located within the northern Big Bend of the southern San Andreas Fault (lat 34.8122° N., lon 118.9034° W.), in a small structural basin formed by the fault (fig. 1). The site has been the focus of over a decade of paleoseismic study due to high stratigraphic resolution and abundant dateable material. Trench 1 (T1) was initially excavated as a 50-m long, fa
Authors
Katherine M. Scharer, Tom E. Fumal, Ray J. Weldon, Ashley R. Streig
The Mw6.0 24 August 2014 South Napa earthquake
The Mw 6.0 South Napa earthquake, which occurred at 10:20 UTC 24 August 2014 was the largest earthquake to strike the greater San Francisco Bay area since the Mw 6.9 1989 Loma Prieta earthquake. The rupture from this right‐lateral earthquake propagated mostly unilaterally to the north and up‐dip, directing the strongest shaking toward the city of Napa, where peak ground accelerations (PGAs) betwee
Authors
Thomas M. Brocher, Annemarie S. Baltay, Jeanne L. Hardebeck, Fred F. Pollitz, Jessica R. Murray, Andrea L. Llenos, David P. Schwartz, J. Luke Blair, Daniel J. Ponti, James J. Lienkaemper, Victoria E. Langenheim, Timothy E. Dawson, Kenneth W. Hudnut, David R. Shelly, Douglas S. Dreger, John Boatwright, Brad T. Aagaard, David J. Wald, Richard M. Allen, William D. Barnhart, Keith L. Knudsen, Benjamin A. Brooks, Katherine M. Scharer
Rapid mapping of ultrafine fault zone topography with structure from motion
Structure from Motion (SfM) generates high-resolution topography and coregistered texture (color) from an unstructured set of overlapping photographs taken from varying viewpoints, overcoming many of the cost, time, and logistical limitations of Light Detection and Ranging (LiDAR) and other topographic surveying methods. This paper provides the first investigation of SfM as a tool for mapping faul
Authors
Kendra Johnson, Edwin Nissen, Srikanth Saripalli, J. Ramón Arrowsmith, Patrick McGarey, Katherine M. Scharer, Patrick Williams, Kimberly Blisniuk
Paleoearthquakes at Frazier Mountain, California delimit extent and frequency of past San Andreas Fault ruptures along 1857 trace
Large earthquakes are infrequent along a single fault, and therefore historic, well-characterized earthquakes exert a strong influence on fault behavior models. This is true of the 1857 Fort Tejon earthquake (estimated M7.7–7.9) on the southern San Andreas Fault (SSAF), but an outstanding question is whether the 330 km long rupture was typical. New paleoseismic data for six to seven ground-rupturi
Authors
Katherine M. Scharer, Ray Weldon, Ashley Streig, Thomas Fumal