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
Ground-motion modeling of Hayward fault scenario earthquakes, part I: Construction of the suite of scenarios Ground-motion modeling of Hayward fault scenario earthquakes, part I: Construction of the suite of scenarios
We construct kinematic earthquake rupture models for a suite of 39 Mw 6.6-7.2 scenario earthquakes involving the Hayward, Calaveras, and Rodgers Creek faults. We use these rupture models in 3D ground-motion simulations as discussed in Part II (Aagaard et al., 2010) to provide detailed estimates of the shaking for each scenario. We employ both geophysical constraints and empirical...
Authors
Brad T. Aagaard, Robert W. Graves, David P. Schwartz, David A. Ponce, Russell W. Graymer
Ground-motion modeling of Hayward fault scenario earthquakes, part II: Simulation of long-period and broadband ground motions Ground-motion modeling of Hayward fault scenario earthquakes, part II: Simulation of long-period and broadband ground motions
We simulate long-period (T>1.0–2.0 s) and broadband (T>0.1 s) ground motions for 39 scenario earthquakes (Mw 6.7–7.2) involving the Hayward, Calaveras, and Rodgers Creek faults. For rupture on the Hayward fault, we consider the effects of creep on coseismic slip using two different approaches, both of which reduce the ground motions, compared with neglecting the influence of creep...
Authors
Brad T. Aagaard, Robert W. Graves, Arthur Rodgers, Thomas M. Brocher, Robert W. Simpson, Douglas Dreger, N. Anders Petersson, Shawn C. Larsen, Shuo Ma, Robert C. Jachens
Data files for ground-motion simulations of the 1906 San Francisco earthquake and scenario earthquakes on the Northern San Andreas Fault Data files for ground-motion simulations of the 1906 San Francisco earthquake and scenario earthquakes on the Northern San Andreas Fault
This data set contains results from ground-motion simulations of the 1906 San Francisco earthquake, seven hypothetical earthquakes on the northern San Andreas Fault, and the 1989 Loma Prieta earthquake. The bulk of the data consists of synthetic velocity time-histories. Peak ground velocity on a 1/60th degree grid and geodetic displacements from the simulations are also included. Details...
Authors
Brad T. Aagaard, Michael Barall, Thomas M. Brocher, David Dolenc, Douglas Dreger, Robert W. Graves, Stephen Harmsen, Stephen H. Hartzell, Shawn Larsen, Kathleen McCandless, Stefan Nilsson, N. Anders Petersson, Arthur Rodgers, Bjorn Sjogreen, Mary Lou Zoback
The SCEC/USGS dynamic earthquake rupture code verification exercise The SCEC/USGS dynamic earthquake rupture code verification exercise
Numerical simulations of earthquake rupture dynamics are now common, yet it has been difficult to test the validity of these simulations because there have been few field observations and no analytic solutions with which to compare the results. This paper describes the Southern California Earthquake Center/U.S. Geological Survey (SCEC/USGS) Dynamic Earthquake Rupture Code Verification...
Authors
R.A. Harris, M. Barall, R. Archuleta, E. Dunham, Brad T. Aagaard, J.-P. Ampuero, H. Bhat, Victor M. Cruz-Atienza, L. Dalguer, P. Dawson, S. Day, B. Duan, G. Ely, Y. Kaneko, Y. Kase, N. Lapusta, Yajing Liu, S. Ma, D. Oglesby, K. Olsen, A. Pitarka, S. Song, E. Templeton
The 1906 San Francisco earthquake a century later: Introduction to the special section The 1906 San Francisco earthquake a century later: Introduction to the special section
The great 1906 San Francisco earthquake is perhaps the landmark event in the history of earthquake science. It began with a foreshock at 5:12 a.m. local time in the morning of 18 April 1906. Some 30 sec later, the main event initiated on the San Andreas fault, just off the San Francisco coast (Lawson, 1908). Within 90 sec, nearly 480 km of the San Andreas fault ruptured (see Fig. 1)...
Authors
Brad T. Aagaard, Gregory C. Beroza
Broadband simulations for Mw 7.8 southern san andreas earthquakes: Ground motion sensitivity to rupture speed Broadband simulations for Mw 7.8 southern san andreas earthquakes: Ground motion sensitivity to rupture speed
Using the high-performance computing resources of the Southern California Earthquake Center, we simulate broadband (0-10 Hz) ground motions for three Mw 7.8 rupture scenarios of the southern San Andreas fault. The scenarios incorporate a kinematic rupture description with the average rupture speed along the large slip portions of the fault set at 0.96, 0.89, and 0.84 times the local...
Authors
R.W. Graves, Brad T. Aagaard, K.W. Hudnut, L.M. Star, J.P. Stewart, T.H. Jordan
Science and Products
Filter Total Items: 48
Ground-motion modeling of Hayward fault scenario earthquakes, part I: Construction of the suite of scenarios Ground-motion modeling of Hayward fault scenario earthquakes, part I: Construction of the suite of scenarios
We construct kinematic earthquake rupture models for a suite of 39 Mw 6.6-7.2 scenario earthquakes involving the Hayward, Calaveras, and Rodgers Creek faults. We use these rupture models in 3D ground-motion simulations as discussed in Part II (Aagaard et al., 2010) to provide detailed estimates of the shaking for each scenario. We employ both geophysical constraints and empirical...
Authors
Brad T. Aagaard, Robert W. Graves, David P. Schwartz, David A. Ponce, Russell W. Graymer
Ground-motion modeling of Hayward fault scenario earthquakes, part II: Simulation of long-period and broadband ground motions Ground-motion modeling of Hayward fault scenario earthquakes, part II: Simulation of long-period and broadband ground motions
We simulate long-period (T>1.0–2.0 s) and broadband (T>0.1 s) ground motions for 39 scenario earthquakes (Mw 6.7–7.2) involving the Hayward, Calaveras, and Rodgers Creek faults. For rupture on the Hayward fault, we consider the effects of creep on coseismic slip using two different approaches, both of which reduce the ground motions, compared with neglecting the influence of creep...
Authors
Brad T. Aagaard, Robert W. Graves, Arthur Rodgers, Thomas M. Brocher, Robert W. Simpson, Douglas Dreger, N. Anders Petersson, Shawn C. Larsen, Shuo Ma, Robert C. Jachens
Data files for ground-motion simulations of the 1906 San Francisco earthquake and scenario earthquakes on the Northern San Andreas Fault Data files for ground-motion simulations of the 1906 San Francisco earthquake and scenario earthquakes on the Northern San Andreas Fault
This data set contains results from ground-motion simulations of the 1906 San Francisco earthquake, seven hypothetical earthquakes on the northern San Andreas Fault, and the 1989 Loma Prieta earthquake. The bulk of the data consists of synthetic velocity time-histories. Peak ground velocity on a 1/60th degree grid and geodetic displacements from the simulations are also included. Details...
Authors
Brad T. Aagaard, Michael Barall, Thomas M. Brocher, David Dolenc, Douglas Dreger, Robert W. Graves, Stephen Harmsen, Stephen H. Hartzell, Shawn Larsen, Kathleen McCandless, Stefan Nilsson, N. Anders Petersson, Arthur Rodgers, Bjorn Sjogreen, Mary Lou Zoback
The SCEC/USGS dynamic earthquake rupture code verification exercise The SCEC/USGS dynamic earthquake rupture code verification exercise
Numerical simulations of earthquake rupture dynamics are now common, yet it has been difficult to test the validity of these simulations because there have been few field observations and no analytic solutions with which to compare the results. This paper describes the Southern California Earthquake Center/U.S. Geological Survey (SCEC/USGS) Dynamic Earthquake Rupture Code Verification...
Authors
R.A. Harris, M. Barall, R. Archuleta, E. Dunham, Brad T. Aagaard, J.-P. Ampuero, H. Bhat, Victor M. Cruz-Atienza, L. Dalguer, P. Dawson, S. Day, B. Duan, G. Ely, Y. Kaneko, Y. Kase, N. Lapusta, Yajing Liu, S. Ma, D. Oglesby, K. Olsen, A. Pitarka, S. Song, E. Templeton
The 1906 San Francisco earthquake a century later: Introduction to the special section The 1906 San Francisco earthquake a century later: Introduction to the special section
The great 1906 San Francisco earthquake is perhaps the landmark event in the history of earthquake science. It began with a foreshock at 5:12 a.m. local time in the morning of 18 April 1906. Some 30 sec later, the main event initiated on the San Andreas fault, just off the San Francisco coast (Lawson, 1908). Within 90 sec, nearly 480 km of the San Andreas fault ruptured (see Fig. 1)...
Authors
Brad T. Aagaard, Gregory C. Beroza
Broadband simulations for Mw 7.8 southern san andreas earthquakes: Ground motion sensitivity to rupture speed Broadband simulations for Mw 7.8 southern san andreas earthquakes: Ground motion sensitivity to rupture speed
Using the high-performance computing resources of the Southern California Earthquake Center, we simulate broadband (0-10 Hz) ground motions for three Mw 7.8 rupture scenarios of the southern San Andreas fault. The scenarios incorporate a kinematic rupture description with the average rupture speed along the large slip portions of the fault set at 0.96, 0.89, and 0.84 times the local...
Authors
R.W. Graves, Brad T. Aagaard, K.W. Hudnut, L.M. Star, J.P. Stewart, T.H. Jordan