William J Stephenson
Bill Stephensen is a scientist in the Earthquake Hazards Program.
Science and Products
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Geophysical characterization of seismic station sites in the United States – The importance of a flexible, multi-method approach Geophysical characterization of seismic station sites in the United States – The importance of a flexible, multi-method approach
Noninvasive geophysical site characterization methods were used in two recent projects to obtain shear-wave velocity (VS) profiles to a minimum depth of 30 m and the time-averaged VS of the upper 30 meters (VS30) at seismic station sites. These projects include the 2009 American Recovery and Reinvestment Act (ARRA) funded U.S. Geological Survey site characterization project for 191 sites...
Authors
Antony Martin, Alan Yong, William Stephenson, J. Boatwright, John Diehl
3D ground‐motion simulations of Mw 7 earthquakes on the Salt Lake City segment of the Wasatch fault zone: Variability of long‐period (T≥1 s) ground motions and sensitivity to kinematic rupture parameters 3D ground‐motion simulations of Mw 7 earthquakes on the Salt Lake City segment of the Wasatch fault zone: Variability of long‐period (T≥1 s) ground motions and sensitivity to kinematic rupture parameters
We examine the variability of long‐period (T≥1 s) earthquake ground motions from 3D simulations of Mw 7 earthquakes on the Salt Lake City segment of the Wasatch fault zone, Utah, from a set of 96 rupture models with varying slip distributions, rupture speeds, slip velocities, and hypocenter locations. Earthquake ruptures were prescribed on a 3D fault representation that satisfies...
Authors
Morgan Moschetti, Stephen Hartzell, Leonardo Ramirez-Guzman, Arthur Frankel, Stephen Angster, William Stephenson
3-D simulations of M9 earthquakes on the Cascadia Megathrust: Key parameters and uncertainty 3-D simulations of M9 earthquakes on the Cascadia Megathrust: Key parameters and uncertainty
Geologic and historical records indicate that the Cascadia subduction zone is capable of generating large, megathrust earthquakes up to magnitude 9. The last great Cascadia earthquake occurred in 1700, and thus there is no direct measure on the intensity of ground shaking or specific rupture parameters from seismic recordings. We use 3-D numerical simulations to generate broadband (0-10...
Authors
Erin Wirth, Arthur Frankel, John Vidale, Nasser Marafi, William Stephenson
The story of a Yakima fold and how it informs Late Neogene and Quaternary backarc deformation in the Cascadia subduction zone, Manastash anticline, Washington, USA The story of a Yakima fold and how it informs Late Neogene and Quaternary backarc deformation in the Cascadia subduction zone, Manastash anticline, Washington, USA
The Yakima folds of central Washington, USA, are prominent anticlines that are the primary tectonic features of the backarc of the northern Cascadia subduction zone. What accounts for their topographic expression and how much strain do they accommodate and over what time period? We investigate Manastash anticline, a north vergent fault propagation fold typical of structures in the fold...
Authors
Harvey Kelsey, Tyler Ladinsky, Lydia Staisch, Brian Sherrod, Richard Blakely, Thomas Pratt, William Stephenson, Jackson K. Odum, Elmira Wan
Continuity of the Reelfoot fault across the Cottonwood Grove and Ridgely faults of the New Madrid Seismic Zone Continuity of the Reelfoot fault across the Cottonwood Grove and Ridgely faults of the New Madrid Seismic Zone
Previous investigators have argued that the northwest-striking Reelfoot fault of northwest Tennessee and southeastern Missouri is segmented. One segment boundary is at the intersection of the northeast-striking Cottonwood Grove and Ridgely strike-slip faults with the Reelfoot fault. We use seismic reflection and geologic mapping to locate and determine the history of the Reelfoot South...
Authors
M.L. Greenwood, Edward Woolery, R. Van Arsdale, William Stephenson, Gary Patterson
The Evergreen basin and the role of the Silver Creek fault in the San Andreas fault system, San Francisco Bay region, California The Evergreen basin and the role of the Silver Creek fault in the San Andreas fault system, San Francisco Bay region, California
The Evergreen basin is a 40-km-long, 8-km-wide Cenozoic sedimentary basin that lies mostly concealed beneath the northeastern margin of the Santa Clara Valley near the south end of San Francisco Bay (California, USA). The basin is bounded on the northeast by the strike-slip Hayward fault and an approximately parallel subsurface fault that is structurally overlain by a set of west-verging...
Authors
Robert Jachens, Carl Wentworth, Russell Graymer, Robert Williams, David Ponce, Edward Mankinen, William Stephenson, Victoria E. Langenheim
Science and Products
Filter Total Items: 15
No Result Found
Filter Total Items: 63
Geophysical characterization of seismic station sites in the United States – The importance of a flexible, multi-method approach Geophysical characterization of seismic station sites in the United States – The importance of a flexible, multi-method approach
Noninvasive geophysical site characterization methods were used in two recent projects to obtain shear-wave velocity (VS) profiles to a minimum depth of 30 m and the time-averaged VS of the upper 30 meters (VS30) at seismic station sites. These projects include the 2009 American Recovery and Reinvestment Act (ARRA) funded U.S. Geological Survey site characterization project for 191 sites...
Authors
Antony Martin, Alan Yong, William Stephenson, J. Boatwright, John Diehl
3D ground‐motion simulations of Mw 7 earthquakes on the Salt Lake City segment of the Wasatch fault zone: Variability of long‐period (T≥1 s) ground motions and sensitivity to kinematic rupture parameters 3D ground‐motion simulations of Mw 7 earthquakes on the Salt Lake City segment of the Wasatch fault zone: Variability of long‐period (T≥1 s) ground motions and sensitivity to kinematic rupture parameters
We examine the variability of long‐period (T≥1 s) earthquake ground motions from 3D simulations of Mw 7 earthquakes on the Salt Lake City segment of the Wasatch fault zone, Utah, from a set of 96 rupture models with varying slip distributions, rupture speeds, slip velocities, and hypocenter locations. Earthquake ruptures were prescribed on a 3D fault representation that satisfies...
Authors
Morgan Moschetti, Stephen Hartzell, Leonardo Ramirez-Guzman, Arthur Frankel, Stephen Angster, William Stephenson
3-D simulations of M9 earthquakes on the Cascadia Megathrust: Key parameters and uncertainty 3-D simulations of M9 earthquakes on the Cascadia Megathrust: Key parameters and uncertainty
Geologic and historical records indicate that the Cascadia subduction zone is capable of generating large, megathrust earthquakes up to magnitude 9. The last great Cascadia earthquake occurred in 1700, and thus there is no direct measure on the intensity of ground shaking or specific rupture parameters from seismic recordings. We use 3-D numerical simulations to generate broadband (0-10...
Authors
Erin Wirth, Arthur Frankel, John Vidale, Nasser Marafi, William Stephenson
The story of a Yakima fold and how it informs Late Neogene and Quaternary backarc deformation in the Cascadia subduction zone, Manastash anticline, Washington, USA The story of a Yakima fold and how it informs Late Neogene and Quaternary backarc deformation in the Cascadia subduction zone, Manastash anticline, Washington, USA
The Yakima folds of central Washington, USA, are prominent anticlines that are the primary tectonic features of the backarc of the northern Cascadia subduction zone. What accounts for their topographic expression and how much strain do they accommodate and over what time period? We investigate Manastash anticline, a north vergent fault propagation fold typical of structures in the fold...
Authors
Harvey Kelsey, Tyler Ladinsky, Lydia Staisch, Brian Sherrod, Richard Blakely, Thomas Pratt, William Stephenson, Jackson K. Odum, Elmira Wan
Continuity of the Reelfoot fault across the Cottonwood Grove and Ridgely faults of the New Madrid Seismic Zone Continuity of the Reelfoot fault across the Cottonwood Grove and Ridgely faults of the New Madrid Seismic Zone
Previous investigators have argued that the northwest-striking Reelfoot fault of northwest Tennessee and southeastern Missouri is segmented. One segment boundary is at the intersection of the northeast-striking Cottonwood Grove and Ridgely strike-slip faults with the Reelfoot fault. We use seismic reflection and geologic mapping to locate and determine the history of the Reelfoot South...
Authors
M.L. Greenwood, Edward Woolery, R. Van Arsdale, William Stephenson, Gary Patterson
The Evergreen basin and the role of the Silver Creek fault in the San Andreas fault system, San Francisco Bay region, California The Evergreen basin and the role of the Silver Creek fault in the San Andreas fault system, San Francisco Bay region, California
The Evergreen basin is a 40-km-long, 8-km-wide Cenozoic sedimentary basin that lies mostly concealed beneath the northeastern margin of the Santa Clara Valley near the south end of San Francisco Bay (California, USA). The basin is bounded on the northeast by the strike-slip Hayward fault and an approximately parallel subsurface fault that is structurally overlain by a set of west-verging...
Authors
Robert Jachens, Carl Wentworth, Russell Graymer, Robert Williams, David Ponce, Edward Mankinen, William Stephenson, Victoria E. Langenheim