Brad Aagaard
Brad Aagaard is a research scientist in the Earthquake Hazards Program.
Ground-motion modeling
- Animations of ground shaking from computer simulations of earthquakes.
- 3D Geologic and Seismic Velocity Model of the San Francisco Bay Region
Software
PyLith crustal deformation modeling software, Computational Infrastructure for Geodynamics.
Professional Experience
Research Geophysicist, USGS, 2003-present
USGS Mendenhall Postdoctoral Scholar, 2001-2003
Education and Certifications
Ph.D., Civil Engineering, California Institute of Technology, 2000
M.S., Civil Engineering, California Institute of Technology, 1995
B.S., Engineering, Harvey Mudd College, 1994
Science and Products
Filter Total Items: 48
Research to improve ShakeAlert earthquake early warning products and their utility Research to improve ShakeAlert earthquake early warning products and their utility
Earthquake early warning (EEW) is the rapid detection of an earthquake and issuance of an alert or notification to people and vulnerable systems likely to experience potentially damaging ground shaking. The level of ground shaking that is considered damaging is defined by the specific application; for example, manufacturing equipment may experience damage at a lower intensity ground...
Authors
Elizabeth S. Cochran, Brad T. Aagaard, Richard M. Allen, Jennifer Andrews, Annemarie S. Baltay Sundstrom, Andrew J. Barbour, Paul Bodin, Benjamin A. Brooks, Angela Chung, Brendan W. Crowell, Douglas D. Given, Thomas C. Hanks, J. Renate Hartog, Egill Hauksson, Thomas H. Heaton, Sara K. McBride, Men-Andrin Meier, Diego Melgar, Sarah E. Minson, Jessica R. Murray, Jennifer A. Strauss, Douglas Toomey
A suite of exercises for verifying dynamic earthquake rupture codes A suite of exercises for verifying dynamic earthquake rupture codes
We describe a set of benchmark exercises that are designed to test if computer codes that simulate dynamic earthquake rupture are working as intended. These types of computer codes are often used to understand how earthquakes operate, and they produce simulation results that include earthquake size, amounts of fault slip, and the patterns of ground shaking and crustal deformation. The...
Authors
Ruth A. Harris, Michael Barall, Brad T. Aagaard, Shuo Ma, Daniel Roten, Kim Olsen, Benchun Duan, Dunyu Liu, Bin Luo, Kangchen Bai, Jean-Paul Ampuero, Yoshihiro Kaneko, Alice-Agnes Gabriel, Kenneth Duru, Thomas Ulrich, Stephanie Wollherr, Zheqiang Shi, Eric Dunham, Sam Bydlon, Zhenguo Zhang, Xiaofei Chen, Surendra N. Somala, Christian Pelties, Josue Tago, Victor Manuel Cruz-Atienza, Jeremy Kozdon, Eric Daub, Khurram Aslam, Yuko Kase, Kyle Withers, Luis Dalguer
Integrate urban‐scale seismic hazard analyses with the U.S. National Seismic Hazard Model Integrate urban‐scale seismic hazard analyses with the U.S. National Seismic Hazard Model
For more than 20 yrs, damage patterns and instrumental recordings have highlighted the influence of the local 3D geologic structure on earthquake ground motions (e.g., MM 6.7 Northridge, California, Gao et al., 1996; MM 6.9 Kobe, Japan, Kawase, 1996; MM 6.8 Nisqually, Washington, Frankel, Carver, and Williams, 2002). Although this and other local‐scale features are critical to improving...
Authors
Morgan P. Moschetti, Nico Luco, Arthur D. Frankel, Mark D. Petersen, Brad T. Aagaard, Annemarie S. Baltay Sundstrom, Michael L. Blanpied, Oliver S. Boyd, Richard W. Briggs, Ryan D. Gold, Robert Graves, Stephen H. Hartzell, Sanaz Rezaeian, William J. Stephenson, David J. Wald, Robert A. Williams, Kyle Withers
U.S. Geological Survey National Strong-Motion Project strategic plan, 2017–22 U.S. Geological Survey National Strong-Motion Project strategic plan, 2017–22
The mission of the National Strong-Motion Project is to provide measurements of how the ground and built environment behave during earthquake shaking to the earthquake engineering community, the scientific community, emergency managers, public agencies, industry, media, and other users for the following purposes: Improving engineering evaluations and design methods for facilities and...
Authors
Brad T. Aagaard, Mehmet Celebi, Lind Gee, Robert Graves, Kishor S. Jaiswal, Erol Kalkan, Keith L. Knudsen, Nico Luco, James Smith, Jamison Steidl, Christopher D. Stephens
Subsurface geometry of the San Andreas fault in southern California: Results from the Salton Seismic Imaging Project (SSIP) and strong ground motion expectations Subsurface geometry of the San Andreas fault in southern California: Results from the Salton Seismic Imaging Project (SSIP) and strong ground motion expectations
The San Andreas fault (SAF) is one of the most studied strike‐slip faults in the world; yet its subsurface geometry is still uncertain in most locations. The Salton Seismic Imaging Project (SSIP) was undertaken to image the structure surrounding the SAF and also its subsurface geometry. We present SSIP studies at two locations in the Coachella Valley of the northern Salton trough. On our...
Authors
Gary S. Fuis, Klaus Bauer, Mark R. Goldman, Trond Ryberg, Victoria E. Langenheim, Daniel S. Scheirer, Michael J. Rymer, Joann M. Stock, John A. Hole, Rufus D. Catchings, Robert Graves, Brad T. Aagaard
Earthquake outlook for the San Francisco Bay region 2014–2043 Earthquake outlook for the San Francisco Bay region 2014–2043
Using information from recent earthquakes, improved mapping of active faults, and a new model for estimating earthquake probabilities, the 2014 Working Group on California Earthquake Probabilities updated the 30-year earthquake forecast for California. They concluded that there is a 72 percent probability (or likelihood) of at least one earthquake of magnitude 6.7 or greater striking...
Authors
Brad T. Aagaard, J. Luke Blair, John Boatwright, Susan H. Garcia, Ruth A. Harris, Andrew J. Michael, David P. Schwartz, Jeanne S. DiLeo
Science and Products
Filter Total Items: 48
Research to improve ShakeAlert earthquake early warning products and their utility Research to improve ShakeAlert earthquake early warning products and their utility
Earthquake early warning (EEW) is the rapid detection of an earthquake and issuance of an alert or notification to people and vulnerable systems likely to experience potentially damaging ground shaking. The level of ground shaking that is considered damaging is defined by the specific application; for example, manufacturing equipment may experience damage at a lower intensity ground...
Authors
Elizabeth S. Cochran, Brad T. Aagaard, Richard M. Allen, Jennifer Andrews, Annemarie S. Baltay Sundstrom, Andrew J. Barbour, Paul Bodin, Benjamin A. Brooks, Angela Chung, Brendan W. Crowell, Douglas D. Given, Thomas C. Hanks, J. Renate Hartog, Egill Hauksson, Thomas H. Heaton, Sara K. McBride, Men-Andrin Meier, Diego Melgar, Sarah E. Minson, Jessica R. Murray, Jennifer A. Strauss, Douglas Toomey
A suite of exercises for verifying dynamic earthquake rupture codes A suite of exercises for verifying dynamic earthquake rupture codes
We describe a set of benchmark exercises that are designed to test if computer codes that simulate dynamic earthquake rupture are working as intended. These types of computer codes are often used to understand how earthquakes operate, and they produce simulation results that include earthquake size, amounts of fault slip, and the patterns of ground shaking and crustal deformation. The...
Authors
Ruth A. Harris, Michael Barall, Brad T. Aagaard, Shuo Ma, Daniel Roten, Kim Olsen, Benchun Duan, Dunyu Liu, Bin Luo, Kangchen Bai, Jean-Paul Ampuero, Yoshihiro Kaneko, Alice-Agnes Gabriel, Kenneth Duru, Thomas Ulrich, Stephanie Wollherr, Zheqiang Shi, Eric Dunham, Sam Bydlon, Zhenguo Zhang, Xiaofei Chen, Surendra N. Somala, Christian Pelties, Josue Tago, Victor Manuel Cruz-Atienza, Jeremy Kozdon, Eric Daub, Khurram Aslam, Yuko Kase, Kyle Withers, Luis Dalguer
Integrate urban‐scale seismic hazard analyses with the U.S. National Seismic Hazard Model Integrate urban‐scale seismic hazard analyses with the U.S. National Seismic Hazard Model
For more than 20 yrs, damage patterns and instrumental recordings have highlighted the influence of the local 3D geologic structure on earthquake ground motions (e.g., MM 6.7 Northridge, California, Gao et al., 1996; MM 6.9 Kobe, Japan, Kawase, 1996; MM 6.8 Nisqually, Washington, Frankel, Carver, and Williams, 2002). Although this and other local‐scale features are critical to improving...
Authors
Morgan P. Moschetti, Nico Luco, Arthur D. Frankel, Mark D. Petersen, Brad T. Aagaard, Annemarie S. Baltay Sundstrom, Michael L. Blanpied, Oliver S. Boyd, Richard W. Briggs, Ryan D. Gold, Robert Graves, Stephen H. Hartzell, Sanaz Rezaeian, William J. Stephenson, David J. Wald, Robert A. Williams, Kyle Withers
U.S. Geological Survey National Strong-Motion Project strategic plan, 2017–22 U.S. Geological Survey National Strong-Motion Project strategic plan, 2017–22
The mission of the National Strong-Motion Project is to provide measurements of how the ground and built environment behave during earthquake shaking to the earthquake engineering community, the scientific community, emergency managers, public agencies, industry, media, and other users for the following purposes: Improving engineering evaluations and design methods for facilities and...
Authors
Brad T. Aagaard, Mehmet Celebi, Lind Gee, Robert Graves, Kishor S. Jaiswal, Erol Kalkan, Keith L. Knudsen, Nico Luco, James Smith, Jamison Steidl, Christopher D. Stephens
Subsurface geometry of the San Andreas fault in southern California: Results from the Salton Seismic Imaging Project (SSIP) and strong ground motion expectations Subsurface geometry of the San Andreas fault in southern California: Results from the Salton Seismic Imaging Project (SSIP) and strong ground motion expectations
The San Andreas fault (SAF) is one of the most studied strike‐slip faults in the world; yet its subsurface geometry is still uncertain in most locations. The Salton Seismic Imaging Project (SSIP) was undertaken to image the structure surrounding the SAF and also its subsurface geometry. We present SSIP studies at two locations in the Coachella Valley of the northern Salton trough. On our...
Authors
Gary S. Fuis, Klaus Bauer, Mark R. Goldman, Trond Ryberg, Victoria E. Langenheim, Daniel S. Scheirer, Michael J. Rymer, Joann M. Stock, John A. Hole, Rufus D. Catchings, Robert Graves, Brad T. Aagaard
Earthquake outlook for the San Francisco Bay region 2014–2043 Earthquake outlook for the San Francisco Bay region 2014–2043
Using information from recent earthquakes, improved mapping of active faults, and a new model for estimating earthquake probabilities, the 2014 Working Group on California Earthquake Probabilities updated the 30-year earthquake forecast for California. They concluded that there is a 72 percent probability (or likelihood) of at least one earthquake of magnitude 6.7 or greater striking...
Authors
Brad T. Aagaard, J. Luke Blair, John Boatwright, Susan H. Garcia, Ruth A. Harris, Andrew J. Michael, David P. Schwartz, Jeanne S. DiLeo