Oliver S Boyd, Ph.D.
Research geophysicist with the U.S. Geological Survey studying various aspects of seismic hazard including ground motions and earthquake probabilities
Biography
I began with the National Seismic Hazards Modeling Project in Golden, CO in 2004 studying time-dependent seismic hazard in Alaska and producing a seismic hazard analysis of Afghanistan, the latter being done in conjunction with other U.S. Agency for International Development’s reconstruction efforts in Afghanistan. I moved to Memphis, TN in 2007 to focus on earthquake hazards in the central and eastern United States (CEUS) and returned to Golden in 2013 to work on issues related to earthquake hazards across the conterminous United States, specifically those related to earthquake ground motions as part of the Ground Motion Project. Much of my past research has centered on several aspects of earthquake hazards including time-dependent earthquake probabilities, declustering of foreshocks and aftershocks, and parameters related to earthquake sources. I helped update the CEUS source models for the 2008 and 2014 updates of the National Seismic Hazard Model (NSHM) and helped to incorporate basin models in the western United States for the 2018 update of the NSHM. More recently, I have been helping to contruct a geology-based National Crustal Model for earthquake hazard studies. Prior to joining the Survey, I obtained my Ph.D. in Geophysics from the University of Colorado at Boulder where I performed laboratory experiments of seismic wave attenuation in artificial glass cracks and glass bead cylinders, produced and interpreted tomographic models of seismic wave attenuation and velocity beneath the western United States, and studied receiver functions in New Zealand.
Science and Products
Thickness of unconsolidated sediments for the USGS National Crustal Model
We present a numeric grid containing estimates of the thickness of unconsolidated sediments for the western United States. Values for these grids were combined and integrated from previous studies or derived directly from gravity analyses. The grids are provided with 1-km grid-node spacing in WGS84 latitude-longitude coordinates. Detailed information regarding the derivation of these estimates...
Depth to Mesozoic basement for the USGS National Crustal Model
We present a numeric grid containing estimates of the depth to the pre-Cenozoic basement for the western United States. Values for these grids were combined and integrated from previous studies or derived directly from gravity analyses. The grids are provided with 1-km grid-node spacing in WGS84 latitude-longitude coordinates. Detailed information regarding the derivation of these estimates is...
3D Geologic Framework for use with the U.S. Geological Survey National Crustal Model, Phase 1: Western United States
A 3D geologic framework is presented here as part of the U.S. Geological Survey National Crustal Model for the western United States, which will be used to improve seismic hazard assessment. The framework is based on 1:250,000 to 1:1,000,000-scale state geologic maps and depths of multiple subsurface unit boundaries. The geology at or near the Earth’s surface is based on publi
Grids in support of the U.S. Geological Survey Thermal Model for Seismic Hazard Studies
A 3D temperature model is constructed in order to support the estimation of physical parameters within the USGS National Crustal Model. The crustal model is defined by a geological framework consisting of various lithologies with distinct mineral compositions. A temperature model is needed to calculate mineral density and bulk and shear modulus as a function of position within the crust. These...
Petrologic and Mineral Physics Database for use with the USGS National Crustal Model - Data Release
We present a petrologic and mineral physics database as part of the USGS National Crustal Model (NCM) for the western United States. Each of 209 geologic units, 134 of which are currently part of the geologic framework within the NCM, is assigned a mineralogical composition according to generalized classifications with some refinement for specific geologic formations. The mineral physics
Calibration Coefficients for the U.S. Geological Survey National Crustal Model and Depth to Water Table
The U.S. Geological Survey National Crustal Model (NCM) is being developed to include spatially varying estimates of site response in seismic hazard assessments. Primary outputs of the NCM are continuous velocity and density profiles from the Earth’s surface to the mantle transition zone at 410 km depth for each location on a 1-kilometer grid across the conterminous United States. Dat
Influence of Lithostatic Stress on Earthquake Stress Drops in North America
Earthquake stress drop is a critical parameter for estimating seismic hazard. This parameter can have a strong effect on ground motion amplitudes above ~1Hz and is especially important in Oklahoma and Kansas where earthquake rates have increased sharply since 2008. We estimate stress drops for 1121 earthquakes greater than ~M3 in and near the conterminous United States using spectral ratios b...
Calibration of the U.S. Geological Survey National Crustal Model
The U.S. Geological Survey National Crustal Model (NCM) is being developed to include spatially varying estimates of site response in seismic hazard assessments. Primary outputs of the NCM are continuous velocity and density profiles from the Earth’s surface to the mantle transition zone at 410-kilometer (km) depth for each location on a 1-km grid...
Boyd, Oliver S.
Temperature model in support of the U.S. Geological Survey National Crustal Model for seismic hazard Ssudies
The U.S. Geological Survey National Crustal Model (NCM) is being developed to assist with earthquake hazard and risk assessment by supporting estimates of ground shaking in response to an earthquake. The period-dependent intensity and duration of shaking depend upon the three-dimensional seismic velocity, seismic attenuation, and density...
Boyd, Oliver S.
The 2018 update of the US National Seismic Hazard Model: Overview of model and implications
During 2017–2018, the National Seismic Hazard Model for the conterminous United States was updated as follows: (1) an updated seismicity catalog was incorporated, which includes new earthquakes that occurred from 2013 to 2017; (2) in the central and eastern United States (CEUS), new ground motion models were updated that incorporate updated median...
Petersen, Mark D.; Shumway, Allison; Powers, Peter M.; Mueller, Charles; Moschetti, Morgan P.; Frankel, Arthur; Rezaeian, Sanaz; McNamara, Daniel E.; Luco, Nicolas; Boyd, Oliver S.; Rukstales, Kenneth S.; Jaiswal, Kishor; Thompson, Eric M.; Hoover, Susan M.; Clayton, Brandon; Field, Edward H.; Zeng, Yuehua
3D geologic framework for use with the U.S. Geological Survey National Crustal Model, Phase 1—Western United States
A 3D geologic framework is presented here as part of the U.S. Geological Survey National Crustal Model for the western United States, which will be used to improve seismic hazard assessment. The framework is based on 1:250,000 to 1:1,000,000-scale state geologic maps and depths of multiple subsurface unit boundaries. The geology at or near the...
Boyd, Oliver S. Status of three-dimensional geological mapping and modeling activities in the U.S. Geological Survey
The U.S. Geological Survey (USGS), created in 1879, is the national geological survey for the United States and the sole science agency within its cabinet-level bureau, the Department of the Interior. The USGS has a broad mission, including: serving the Nation by providing reliable scientific information to describe and understand the Earth;...
Sweetkind, Donald; Graymer, Russell; Higley, D.K.; Boyd, Oliver S.
Petrologic and mineral physics database for use with the U.S. Geological Survey National Crustal Model
We present a petrologic and mineral physics database as part of the U.S. Geological Survey National Crustal Model (NCM). Each of 209 geologic units, 134 of which are currently part of the geologic framework within the NCM, was assigned a mineralogical composition according to generalized classifications with some refinement for specific geologic...
Sowers, Theron; Boyd, Oliver S. The USGS National crustal model for seismic hazard studies: 2019 update
The United States Geological Survey (USGS) National Crustal Model (NCM) is being developed to assist in the modeling of seismic hazards across the conterminous United States, specifically by improving estimates of site response. The NCM is composed of geophysical profiles, extending from the Earth’s surface into the upper mantle, constructed from...
Boyd, Oliver S. Preliminary 2018 national seismic hazard model for the conterminous United States
The 2014 U.S. Geological Survey national seismic hazard model for the conterminous U.S. will be updated in 2018 and 2020 to coincide with the Building Seismic Safety Council’s Project 17 timeline for development of new building code design criteria. The two closely timed updates are planned to allow more time for the Provisions Update Committee to...
Petersen, Mark D.; Shumway, Allison; Powers, Peter M.; Mueller, Charles; Rezaeian, Sanaz; Moschetti, Morgan P.; McNamara, Daniel E.; Thompson, Eric M.; Boyd, Oliver S.; Luco, Nicolas; Hoover, Susan M.; Rukstales, Kenneth S.
Depth to basement and thickness of unconsolidated sediments for the western United States—Initial estimates for layers of the U.S. Geological Survey National Crustal Model
We present numeric grids containing estimates of the thickness of unconsolidated sediments and depth to the pre-Cenozoicbasement for the western United States. Values for these grids were combined and integrated from previous studies or deriveddirectly from gravity analyses. The grids are provided with 1-kilometer grid-node spacing in ScienceBase...
Shah, Anjana K.; Boyd, Oliver S. An updated stress map of the continental U.S. reveals heterogeneous intraplate stress
Knowledge of the state of stress in the Earth’s crust is key to understanding the forces and processes responsible for earthquakes. Historically, low rates of natural seismicity in the central and eastern United States have complicated efforts to understand intraplate stress, but recent improvements in seismic networks and the spread of human-...
Levandowski, Will; Hermann, Robert B; Briggs, Richard W.; Boyd, Oliver S.; Gold, Ryan D. 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., M">MM 6.7 Northridge, California, Gao et al., 1996; M">MM 6.9 Kobe, Japan, Kawase, 1996; M">MM 6.8 Nisqually,...
Moschetti, Morgan P.; Luco, Nicolas; Frankel, Arthur; Petersen, Mark D.; Aagaard, Brad T.; Baltay, Annemarie S.; Blanpied, Michael; Boyd, Oliver S.; Briggs, Richard W.; Gold, Ryan D.; Graves, Robert; Hartzell, Stephen H.; Rezaeian, Sanaz; Stephenson, William J.; Wald, David J.; Williams, Robert A.; Withers, Kyle Influence of lithostatic stress on earthquake stress drops in North America
We estimate stress drops for earthquakes in and near the continental United States using the method of spectral ratios. The ratio of acceleration spectra between collocated earthquakes recorded at a given station removes the effects of path and recording site and yields source parameters including corner frequency for, and the ratio of seismic...
Boyd, Oliver S.; McNamara, Daniel E.; Hartzell, Stephen H.; Choy, George