Sean Kamran Ahdi (Former Employee)
Science and Products
Filter Total Items: 19
The 2023 US 50-State National Seismic Hazard Model: Overview and implications The 2023 US 50-State National Seismic Hazard Model: Overview and implications
The US National Seismic Hazard Model (NSHM) was updated in 2023 for all 50 states using new science on seismicity, fault ruptures, ground motions, and probabilistic techniques to produce a standard of practice for public policy and other engineering applications (defined for return periods greater than ∼475 or less than ∼10,000 years). Changes in 2023 time-independent seismic hazard...
Authors
Mark D. Petersen, Allison Shumway, Peter M. Powers, Edward H. Field, Morgan P. Moschetti, Kishor S. Jaiswal, Kevin R. Milner, Sanaz Rezaeian, Arthur D. Frankel, Andrea L. Llenos, Andrew J. Michael, Jason M. Altekruse, Sean Kamran Ahdi, Kyle Withers, Charles Mueller, Yuehua Zeng, Robert E. Chase, Leah M. Salditch, Nico Luco, Kenneth S. Rukstales, Julie A. Herrick, Demi Leafar Girot, Brad T. Aagaard, Adrian Bender, Michael L. Blanpied, Richard W. Briggs, Oliver S. Boyd, Brandon Clayton, Christopher DuRoss, Eileen L. Evans, Peter J. Haeussler, Alexandra Elise Hatem, Kirstie Lafon Haynie, Elizabeth H. Hearn, Kaj M. Johnson, Zachary Alan Kortum, N. Simon Kwong, Andrew James Makdisi, Henry Mason, Daniel McNamara, Devin McPhillips, P. Okubo, Morgan T. Page, Frederick Pollitz, Justin Rubinstein, Bruce E. Shaw, Zheng-Kang Shen, Brian Shiro, James Andrew Smith, William J. Stephenson, Eric M. Thompson, Jessica Ann Thompson Jobe, Erin A. Wirth, Robert C. Witter
Sediment thickness map of United States Atlantic and Gulf Coastal Plain Strata, and their influence on earthquake ground motions Sediment thickness map of United States Atlantic and Gulf Coastal Plain Strata, and their influence on earthquake ground motions
With the recent successful accounting of basin depth ground-motion adjustments in seismic hazard analyses for select areas of the western United States, we move toward implementing similar adjustments in the Atlantic and Gulf Coastal Plains by constructing a sediment thickness model and evaluating multiple relevant site amplification models for central and eastern United States seismic...
Authors
Oliver S. Boyd, David Churchwell, Morgan P. Moschetti, Eric M. Thompson, Martin C. Chapman, Okan Ilhan, Thomas L. Pratt, Sean Kamran Ahdi, Sanaz Rezaeian
COSMOS Ground-Motion Simulation Working Group workshops #1 and #2 COSMOS Ground-Motion Simulation Working Group workshops #1 and #2
These 2 workshops were held in response to interest generated from sessions on the use of simulated earthquake ground motions at the 2020 and 2021 Consortium of Organizations for Strong Motion Observation Systems (COSMOS) Technical Sessions. The discussions at the Technical Sessions highlighted desires to promote the use of simulated earthquake ground motions for engineering applications...
Authors
Brad T. Aagaard, Aysegul Askan, Sanaz Rezaeian, Sean Kamran Ahdi, Alan Yong
Implementation of basin models and sediment depth terms in the 2023 update of the U.S. National Seismic Hazard Model: Example from Reno, Nevada Implementation of basin models and sediment depth terms in the 2023 update of the U.S. National Seismic Hazard Model: Example from Reno, Nevada
We present a framework to evaluate the inclusion of candidate basin depth models in the U.S. Geological Survey National Seismic Hazard Model. We compute intensity measures (peak and spectral amplitudes) from uniformly processed earthquake ground motions in and around the basin of interest and compare these to ground-motion model (GMM) estimates over a range of oscillator periods. The...
Authors
Sean Kamran Ahdi, Morgan P. Moschetti, Brad T. Aagaard, Kaitlyn Abernathy, Oliver S. Boyd, William J. Stephenson
NGA-Subduction research program NGA-Subduction research program
This article summarizes the Next Generation Attenuation (NGA) Subduction (NGA-Sub) project, a major research program to develop a database and ground motion models (GMMs) for subduction regions. A comprehensive database of subduction earthquakes recorded worldwide was developed. The database includes a total of 214,020 individual records from 1,880 subduction events, which is by far the...
Authors
Yousef Bozorgnia, Norman A. Abrahamson, Sean Kamran Ahdi, Timothy D. Ancheta, Linda Al Atik, Ralph J. Archuleta, Gail M. Atkinson, David M Boore, Kenneth W. Campbell, Brian S-J Chiou, Victor Contreras, Robert B. Darragh, Sahar Derakhshan, Jennifer L Donahue, Nick Gregor, Zeynep Gulerce, Izzat M Idriss, Chengxin Jiang, Tadahiro Kishida, Albert R. Kottke, Nicolas Kuehn, Dongyoup Kwak, Annie O-L Kwok, Person Lin, Jorge Macedo, Silvia Mazzoni, Saburoh Midorikawa, Sifat Muin, Grace Alexandra Parker, Sanaz Rezaeian, Hongjun Si, Walter J Silva, Jonathan P. Stewart, Melanie Walling, Katie Wooddell, Robert R Youngs
Relational database for horizontal‐to‐vertical spectral ratios Relational database for horizontal‐to‐vertical spectral ratios
Frequency‐dependent horizontal‐to‐vertical spectral ratios (HVSRs) of Fourier amplitudes from three‐component recordings can provide useful information for site response modeling. However, such information is not incorporated into most ground‐motion models, including those from Next‐Generation Attenuation projects, which instead use the time‐averaged shear‐wave velocity (VSVS) in the...
Authors
Pengfei Wang, Paolo Zimmaro, Tristan E Buckreis, Tatiana Gospe, Scott J Brandenberg, Sean Kamran Ahdi, Alan Yong, Jonathan P. Stewart
Science and Products
Filter Total Items: 19
The 2023 US 50-State National Seismic Hazard Model: Overview and implications The 2023 US 50-State National Seismic Hazard Model: Overview and implications
The US National Seismic Hazard Model (NSHM) was updated in 2023 for all 50 states using new science on seismicity, fault ruptures, ground motions, and probabilistic techniques to produce a standard of practice for public policy and other engineering applications (defined for return periods greater than ∼475 or less than ∼10,000 years). Changes in 2023 time-independent seismic hazard...
Authors
Mark D. Petersen, Allison Shumway, Peter M. Powers, Edward H. Field, Morgan P. Moschetti, Kishor S. Jaiswal, Kevin R. Milner, Sanaz Rezaeian, Arthur D. Frankel, Andrea L. Llenos, Andrew J. Michael, Jason M. Altekruse, Sean Kamran Ahdi, Kyle Withers, Charles Mueller, Yuehua Zeng, Robert E. Chase, Leah M. Salditch, Nico Luco, Kenneth S. Rukstales, Julie A. Herrick, Demi Leafar Girot, Brad T. Aagaard, Adrian Bender, Michael L. Blanpied, Richard W. Briggs, Oliver S. Boyd, Brandon Clayton, Christopher DuRoss, Eileen L. Evans, Peter J. Haeussler, Alexandra Elise Hatem, Kirstie Lafon Haynie, Elizabeth H. Hearn, Kaj M. Johnson, Zachary Alan Kortum, N. Simon Kwong, Andrew James Makdisi, Henry Mason, Daniel McNamara, Devin McPhillips, P. Okubo, Morgan T. Page, Frederick Pollitz, Justin Rubinstein, Bruce E. Shaw, Zheng-Kang Shen, Brian Shiro, James Andrew Smith, William J. Stephenson, Eric M. Thompson, Jessica Ann Thompson Jobe, Erin A. Wirth, Robert C. Witter
Sediment thickness map of United States Atlantic and Gulf Coastal Plain Strata, and their influence on earthquake ground motions Sediment thickness map of United States Atlantic and Gulf Coastal Plain Strata, and their influence on earthquake ground motions
With the recent successful accounting of basin depth ground-motion adjustments in seismic hazard analyses for select areas of the western United States, we move toward implementing similar adjustments in the Atlantic and Gulf Coastal Plains by constructing a sediment thickness model and evaluating multiple relevant site amplification models for central and eastern United States seismic...
Authors
Oliver S. Boyd, David Churchwell, Morgan P. Moschetti, Eric M. Thompson, Martin C. Chapman, Okan Ilhan, Thomas L. Pratt, Sean Kamran Ahdi, Sanaz Rezaeian
COSMOS Ground-Motion Simulation Working Group workshops #1 and #2 COSMOS Ground-Motion Simulation Working Group workshops #1 and #2
These 2 workshops were held in response to interest generated from sessions on the use of simulated earthquake ground motions at the 2020 and 2021 Consortium of Organizations for Strong Motion Observation Systems (COSMOS) Technical Sessions. The discussions at the Technical Sessions highlighted desires to promote the use of simulated earthquake ground motions for engineering applications...
Authors
Brad T. Aagaard, Aysegul Askan, Sanaz Rezaeian, Sean Kamran Ahdi, Alan Yong
Implementation of basin models and sediment depth terms in the 2023 update of the U.S. National Seismic Hazard Model: Example from Reno, Nevada Implementation of basin models and sediment depth terms in the 2023 update of the U.S. National Seismic Hazard Model: Example from Reno, Nevada
We present a framework to evaluate the inclusion of candidate basin depth models in the U.S. Geological Survey National Seismic Hazard Model. We compute intensity measures (peak and spectral amplitudes) from uniformly processed earthquake ground motions in and around the basin of interest and compare these to ground-motion model (GMM) estimates over a range of oscillator periods. The...
Authors
Sean Kamran Ahdi, Morgan P. Moschetti, Brad T. Aagaard, Kaitlyn Abernathy, Oliver S. Boyd, William J. Stephenson
NGA-Subduction research program NGA-Subduction research program
This article summarizes the Next Generation Attenuation (NGA) Subduction (NGA-Sub) project, a major research program to develop a database and ground motion models (GMMs) for subduction regions. A comprehensive database of subduction earthquakes recorded worldwide was developed. The database includes a total of 214,020 individual records from 1,880 subduction events, which is by far the...
Authors
Yousef Bozorgnia, Norman A. Abrahamson, Sean Kamran Ahdi, Timothy D. Ancheta, Linda Al Atik, Ralph J. Archuleta, Gail M. Atkinson, David M Boore, Kenneth W. Campbell, Brian S-J Chiou, Victor Contreras, Robert B. Darragh, Sahar Derakhshan, Jennifer L Donahue, Nick Gregor, Zeynep Gulerce, Izzat M Idriss, Chengxin Jiang, Tadahiro Kishida, Albert R. Kottke, Nicolas Kuehn, Dongyoup Kwak, Annie O-L Kwok, Person Lin, Jorge Macedo, Silvia Mazzoni, Saburoh Midorikawa, Sifat Muin, Grace Alexandra Parker, Sanaz Rezaeian, Hongjun Si, Walter J Silva, Jonathan P. Stewart, Melanie Walling, Katie Wooddell, Robert R Youngs
Relational database for horizontal‐to‐vertical spectral ratios Relational database for horizontal‐to‐vertical spectral ratios
Frequency‐dependent horizontal‐to‐vertical spectral ratios (HVSRs) of Fourier amplitudes from three‐component recordings can provide useful information for site response modeling. However, such information is not incorporated into most ground‐motion models, including those from Next‐Generation Attenuation projects, which instead use the time‐averaged shear‐wave velocity (VSVS) in the...
Authors
Pengfei Wang, Paolo Zimmaro, Tristan E Buckreis, Tatiana Gospe, Scott J Brandenberg, Sean Kamran Ahdi, Alan Yong, Jonathan P. Stewart