Paul A Bedrosian
Paul is an expert in the development and application of electromagnetic geophysical methods to framework tectonics, resource assessment, natural hazards and fundamental Earth processes. His work has investigated seismic variability along the San Andreas Fault, tectonics of the Pacific Northwest and Upper Midwest, and the structure of Mount St. Helens. His current research is on regional-scale mine
Research Interests
- Structure and evolution of active and fossil tectonic margins
- Geophysical imaging of hydrothermal and magmatic systems
- Joint interpretation of coincident geophysical data sets
- Advanced processing and modeling techniques for imaging earth structure
Professional Experience
2008-present, Research Geophysicist, U.S. Geological Survey, Denver, Colorado
2005-2007, Mendenhall Fellow, U.S Geological Survey, Denver, Colorado
2002-2004, Humboldt Fellow, GeoForschungsZentrum, Potsdam Germany
1998-2002, Research Assistant, University of Washington, Seattle, Washington
Education and Certifications
Ph.D. Physics, University of Washington, 2002
M.S. Physics, University of Washington, 1998
B.S. Physics, University Of Minnesota, 1996
B.S. Chemistry, University of Minnesota, 1996
Affiliations and Memberships*
2010-present, Summer of Applied Geophysical Experience (faculty)
2018-present, Earth, Planets and Space Journal (editor)
American Geophysical Union
Geological Society of America
Science and Products
Filter Total Items: 13
No Result Found
Filter Total Items: 83
Mapping geoelectric fields during magnetic storms: Synthetic analysis of empirical United States impedances Mapping geoelectric fields during magnetic storms: Synthetic analysis of empirical United States impedances
Empirical impedance tensors obtained from EarthScope magnetotelluric data at sites distributed across the midwestern United States are used to examine the feasibility of mapping magnetic storm induction of geoelectric fields. With these tensors, in order to isolate the effects of Earth conductivity structure, we perform a synthetic analysis—calculating geoelectric field variations...
Authors
Paul A. Bedrosian, Jeffrey J. Love
A one-dimensional model of solid-earth electrical resistivity beneath Florida A one-dimensional model of solid-earth electrical resistivity beneath Florida
An estimated one-dimensional layered model of electrical resistivity beneath Florida was developed from published geological and geophysical information. The resistivity of each layer is represented by plausible upper and lower bounds as well as a geometric mean resistivity. Corresponding impedance transfer functions, Schmucker-Weidelt transfer functions, apparent resistivity, and phase...
Authors
Cletus Blum, Jeffrey J. Love, Kolby Pedrie, Paul A. Bedrosian, E. Joshua Rigler
Summer of Applied Geophysical Experience (SAGE): Training for our future geoscientists Summer of Applied Geophysical Experience (SAGE): Training for our future geoscientists
Energy and natural resources are crucial to the sustainability of worldwide economies, security, and overall well-being. However, the future workforce in the energy and natural-resources sector is at risk, and meeting the challenges of this dwindling workforce requires well-educated geoscientists in exploration and applied geophysics and related geoscience and technology disciplines...
Authors
W.S. Baldridge, Paul A. Bedrosian, Shawn Biehler, L.W. Braile, John Ferguson, Matthew Folsom, G.R. Jiracek, Shari A. Kelley, Darcy McPhee, Louise Pellerin, Catherine M. Snelson
Mapping the 3-D extent of the Northern Lobe of the Bushveld layered mafic intrusion from geophysical data Mapping the 3-D extent of the Northern Lobe of the Bushveld layered mafic intrusion from geophysical data
Geophysical models image the 3D geometry of the mafic portion of the Bushveld Complex north of the Thabazimbi-Murchison Lineament (TML), critical for understanding the origin of the world's largest layered mafic intrusion and platinum group element deposits. The combination of the gravity and magnetic data with recent seismic, MT, borehole and rock property measurements powerfully...
Authors
Carol A. Finn, Paul A. Bedrosian, Janine Cole, Tshepo David Khoza, Susan J. Webb
Airborne electromagnetic and magnetic survey data of the Paradox and San Luis Valleys, Colorado Airborne electromagnetic and magnetic survey data of the Paradox and San Luis Valleys, Colorado
In October 2011, the U.S. Geological Survey (USGS) contracted airborne magnetic and electromagnetic surveys of the Paradox and San Luis Valleys in southern Colorado, United States. These airborne geophysical surveys provide high-resolution and spatially comprehensive datasets characterizing the resistivity structure of the shallow subsurface of each survey region, accompanied by magnetic...
Authors
Lyndsay B. Ball, Benjamin R. Bloss, Paul A. Bedrosian, V. J. S. Grauch, Bruce D. Smith
Laboratory electrical resistivity analysis of geologic samples from Fort Irwin, California Laboratory electrical resistivity analysis of geologic samples from Fort Irwin, California
Correlating laboratory resistivity measurements with geophysical resistivity models helps constrain these models to the geology and lithology of an area. Throughout the Fort Irwin National Training Center area, 111 samples from both cored boreholes and surface outcrops were collected and processed for laboratory measurements. These samples represent various lithologic types that include...
Authors
Benjamin R. Bloss, Paul A. Bedrosian
Joint inversion of seismic and magnetotelluric data in the Parkfield Region of California using the normalized cross-gradient constraint Joint inversion of seismic and magnetotelluric data in the Parkfield Region of California using the normalized cross-gradient constraint
We present jointly inverted models of P-wave velocity (Vp) and electrical resistivity for a two-dimensional profile centered on the San Andreas Fault Observatory at Depth (SAFOD). Significant structural similarity between main features of the separately inverted Vp and resistivity models is exploited by carrying out a joint inversion of the two datasets using the normalized cross...
Authors
Ninfa L. Bennington, Haijiang Zhang, Cliff Thurber, Paul A. Bedrosian
Structure and tectonics of the northwestern United States from EarthScope USArray magnetotelluric data Structure and tectonics of the northwestern United States from EarthScope USArray magnetotelluric data
The magnetotelluric component of the EarthScope USArray program has covered over 35% of the continental United States. Resistivity tomography models derived from these data image lithospheric structure and provide constraints on the distribution of fluids and melt within the lithosphere. We present a three-dimensional resistivity model of the northwestern United States which provides new...
Authors
Paul A. Bedrosian, Daniel W. Feucht
Segmentation of plate coupling, fate of subduction fluids, and modes of arc magmatism in Cascadia, inferred from magnetotelluric resistivity Segmentation of plate coupling, fate of subduction fluids, and modes of arc magmatism in Cascadia, inferred from magnetotelluric resistivity
Five magnetotelluric (MT) profiles have been acquired across the Cascadia subduction system and transformed using 2-D and 3-D nonlinear inversion to yield electrical resistivity cross sections to depths of ∼200 km. Distinct changes in plate coupling, subduction fluid evolution, and modes of arc magmatism along the length of Cascadia are clearly expressed in the resistivity structure...
Authors
Philip E. Wannamaker, Rob L. Evans, Paul A. Bedrosian, Martyn J. Unsworth, Virginie Maris, R. Shane McGary
Geophysical investigations of the geologic and hydrothermal framework of the Pilgrim Springs Geothermal Area, Alaska Geophysical investigations of the geologic and hydrothermal framework of the Pilgrim Springs Geothermal Area, Alaska
Pilgrim Hot Springs, located on the Seward Peninsula in west-central Alaska, is characterized by hot springs, surrounding thawed regions, and elevated lake temperatures. The area is of interest because of its potential for providing renewable energy for Nome and nearby rural communities. We performed ground and airborne geophysical investigations of the Pilgrim Springs geothermal area to...
Authors
Jonathan M.G. Glen, Darcy McPhee, Paul A. Bedrosian
Airborne electromagnetic data and processing within Leach Lake Basin, Fort Irwin, California Airborne electromagnetic data and processing within Leach Lake Basin, Fort Irwin, California
From December 2010 to January 2011, the U.S. Geological Survey conducted airborne electromagnetic and magnetic surveys of Leach Lake Basin within the National Training Center, Fort Irwin, California. These data were collected to characterize the subsurface and provide information needed to understand and manage groundwater resources within Fort Irwin. A resistivity stratigraphy was...
Authors
Paul A. Bedrosian, Lyndsay B. Ball, Benjamin R. Bloss
Time-domain electromagnetic surveys at Fort Irwin, San Bernardino County, California, 2010–12 Time-domain electromagnetic surveys at Fort Irwin, San Bernardino County, California, 2010–12
Between 2010 and 2012, a total of 79 time-domain electromagnetic (TEM) soundings were collected in 12 groundwater basins in the U.S. Army Fort Irwin National Training Center (NTC) study area to help improve the understanding of the hydrogeology of the NTC. The TEM data are discussed in this chapter in the context of geologic observations of the study area, the details of which are...
Authors
Matthew K. Burgess, Paul A. Bedrosian
Non-USGS Publications**
P.A. Bedrosian, M.J. Unsworth, G.D. Egbert and C.H. Thurber. 2004. Geophysical images of the creeping San Andreas Fault: Implications for the role of crustal fluids in the earthquake process, Tectonophys., 385(1-4), doi:10.1016/j.tecto.2004.02.010.
M.J. Unsworth and P.A. Bedrosian. 2004. Electrical resistivity structure at the SAFOD site from magnetotelluric exploration, Geophys. Res. Lett., 31(12), doi:10.1029/2003GL019045.
M.J. Unsworth and P.A. Bedrosian. 2004. On the geoelectric structure of major strike-slip faults and shear zones., Earth, Planets and Space, 56, 1177–1184, doi:10.1186/BF03353337.
M.J. Unsworth, W. Wenbo, A. G. Jones, S. Li, P.A. Bedrosian, J. Booker, J. Sheng, D. Ming and T. Handong. 2004. Crustal and upper mantle structure of Northern Tibet imaged with magnetotelluric data, J. Geophys. Res., 109, doi:10.1029/2002JB002305.
P.A. Bedrosian, M.J. Unsworth and G.D. Egbert. 2002. Magnetotelluric imaging of the creeping segment of the San Andreas Fault near Hollister, Geophys. Res. Lett., 29(11), 1506, doi:10.1029/2001GL014119.
M. Unsworth, O.C. Enriquez, S. Belmonte, J. Arzate and P.A. Bedrosian. 2002. Crustal structure of the Chicxulub Impact Crater imaged with magnetotelluric exploration, Geophys. Res. Lett., 29(16), 1788, doi:10.1029/2002GL014998.
P.A. Bedrosian, M.J. Unsworth and F. Wang. 2001. Structure of the Altyn Tagh Fault and Daxue Shan from magnetotelluric surveys: Implications for faulting associated with the rise of the Tibetan Plateau, Tectonics, 20, 474-486, doi:10.1029/2000TC001215.
W. Wenbo, M. Unsworth, A. Jones, J. Booker, H. Tan, D. Nelson, L. Chen, S. Li, K. Solon, P.A. Bedrosian, S. Jin, M. Deng, J. Ledo, D. Kay and B. Roberts. 2001. Widespread fluids in the Tibetan Crust, Science, 292(5517), 716-718, doi:10.1126/science.1010580.
M. Unsworth, P.A. Bedrosian, M. Eisel, G. Egbert and W. Siripunvaraporn. 2000. Along-strike variations in the electrical structure of the San Andreas Fault at Parkfield, California, Geophys. Res. Lett., 27(18), 3021-3024, doi:10.1029/2000GL011476.
**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.
Science and Products
Filter Total Items: 13
No Result Found
Filter Total Items: 83
Mapping geoelectric fields during magnetic storms: Synthetic analysis of empirical United States impedances Mapping geoelectric fields during magnetic storms: Synthetic analysis of empirical United States impedances
Empirical impedance tensors obtained from EarthScope magnetotelluric data at sites distributed across the midwestern United States are used to examine the feasibility of mapping magnetic storm induction of geoelectric fields. With these tensors, in order to isolate the effects of Earth conductivity structure, we perform a synthetic analysis—calculating geoelectric field variations...
Authors
Paul A. Bedrosian, Jeffrey J. Love
A one-dimensional model of solid-earth electrical resistivity beneath Florida A one-dimensional model of solid-earth electrical resistivity beneath Florida
An estimated one-dimensional layered model of electrical resistivity beneath Florida was developed from published geological and geophysical information. The resistivity of each layer is represented by plausible upper and lower bounds as well as a geometric mean resistivity. Corresponding impedance transfer functions, Schmucker-Weidelt transfer functions, apparent resistivity, and phase...
Authors
Cletus Blum, Jeffrey J. Love, Kolby Pedrie, Paul A. Bedrosian, E. Joshua Rigler
Summer of Applied Geophysical Experience (SAGE): Training for our future geoscientists Summer of Applied Geophysical Experience (SAGE): Training for our future geoscientists
Energy and natural resources are crucial to the sustainability of worldwide economies, security, and overall well-being. However, the future workforce in the energy and natural-resources sector is at risk, and meeting the challenges of this dwindling workforce requires well-educated geoscientists in exploration and applied geophysics and related geoscience and technology disciplines...
Authors
W.S. Baldridge, Paul A. Bedrosian, Shawn Biehler, L.W. Braile, John Ferguson, Matthew Folsom, G.R. Jiracek, Shari A. Kelley, Darcy McPhee, Louise Pellerin, Catherine M. Snelson
Mapping the 3-D extent of the Northern Lobe of the Bushveld layered mafic intrusion from geophysical data Mapping the 3-D extent of the Northern Lobe of the Bushveld layered mafic intrusion from geophysical data
Geophysical models image the 3D geometry of the mafic portion of the Bushveld Complex north of the Thabazimbi-Murchison Lineament (TML), critical for understanding the origin of the world's largest layered mafic intrusion and platinum group element deposits. The combination of the gravity and magnetic data with recent seismic, MT, borehole and rock property measurements powerfully...
Authors
Carol A. Finn, Paul A. Bedrosian, Janine Cole, Tshepo David Khoza, Susan J. Webb
Airborne electromagnetic and magnetic survey data of the Paradox and San Luis Valleys, Colorado Airborne electromagnetic and magnetic survey data of the Paradox and San Luis Valleys, Colorado
In October 2011, the U.S. Geological Survey (USGS) contracted airborne magnetic and electromagnetic surveys of the Paradox and San Luis Valleys in southern Colorado, United States. These airborne geophysical surveys provide high-resolution and spatially comprehensive datasets characterizing the resistivity structure of the shallow subsurface of each survey region, accompanied by magnetic...
Authors
Lyndsay B. Ball, Benjamin R. Bloss, Paul A. Bedrosian, V. J. S. Grauch, Bruce D. Smith
Laboratory electrical resistivity analysis of geologic samples from Fort Irwin, California Laboratory electrical resistivity analysis of geologic samples from Fort Irwin, California
Correlating laboratory resistivity measurements with geophysical resistivity models helps constrain these models to the geology and lithology of an area. Throughout the Fort Irwin National Training Center area, 111 samples from both cored boreholes and surface outcrops were collected and processed for laboratory measurements. These samples represent various lithologic types that include...
Authors
Benjamin R. Bloss, Paul A. Bedrosian
Joint inversion of seismic and magnetotelluric data in the Parkfield Region of California using the normalized cross-gradient constraint Joint inversion of seismic and magnetotelluric data in the Parkfield Region of California using the normalized cross-gradient constraint
We present jointly inverted models of P-wave velocity (Vp) and electrical resistivity for a two-dimensional profile centered on the San Andreas Fault Observatory at Depth (SAFOD). Significant structural similarity between main features of the separately inverted Vp and resistivity models is exploited by carrying out a joint inversion of the two datasets using the normalized cross...
Authors
Ninfa L. Bennington, Haijiang Zhang, Cliff Thurber, Paul A. Bedrosian
Structure and tectonics of the northwestern United States from EarthScope USArray magnetotelluric data Structure and tectonics of the northwestern United States from EarthScope USArray magnetotelluric data
The magnetotelluric component of the EarthScope USArray program has covered over 35% of the continental United States. Resistivity tomography models derived from these data image lithospheric structure and provide constraints on the distribution of fluids and melt within the lithosphere. We present a three-dimensional resistivity model of the northwestern United States which provides new...
Authors
Paul A. Bedrosian, Daniel W. Feucht
Segmentation of plate coupling, fate of subduction fluids, and modes of arc magmatism in Cascadia, inferred from magnetotelluric resistivity Segmentation of plate coupling, fate of subduction fluids, and modes of arc magmatism in Cascadia, inferred from magnetotelluric resistivity
Five magnetotelluric (MT) profiles have been acquired across the Cascadia subduction system and transformed using 2-D and 3-D nonlinear inversion to yield electrical resistivity cross sections to depths of ∼200 km. Distinct changes in plate coupling, subduction fluid evolution, and modes of arc magmatism along the length of Cascadia are clearly expressed in the resistivity structure...
Authors
Philip E. Wannamaker, Rob L. Evans, Paul A. Bedrosian, Martyn J. Unsworth, Virginie Maris, R. Shane McGary
Geophysical investigations of the geologic and hydrothermal framework of the Pilgrim Springs Geothermal Area, Alaska Geophysical investigations of the geologic and hydrothermal framework of the Pilgrim Springs Geothermal Area, Alaska
Pilgrim Hot Springs, located on the Seward Peninsula in west-central Alaska, is characterized by hot springs, surrounding thawed regions, and elevated lake temperatures. The area is of interest because of its potential for providing renewable energy for Nome and nearby rural communities. We performed ground and airborne geophysical investigations of the Pilgrim Springs geothermal area to...
Authors
Jonathan M.G. Glen, Darcy McPhee, Paul A. Bedrosian
Airborne electromagnetic data and processing within Leach Lake Basin, Fort Irwin, California Airborne electromagnetic data and processing within Leach Lake Basin, Fort Irwin, California
From December 2010 to January 2011, the U.S. Geological Survey conducted airborne electromagnetic and magnetic surveys of Leach Lake Basin within the National Training Center, Fort Irwin, California. These data were collected to characterize the subsurface and provide information needed to understand and manage groundwater resources within Fort Irwin. A resistivity stratigraphy was...
Authors
Paul A. Bedrosian, Lyndsay B. Ball, Benjamin R. Bloss
Time-domain electromagnetic surveys at Fort Irwin, San Bernardino County, California, 2010–12 Time-domain electromagnetic surveys at Fort Irwin, San Bernardino County, California, 2010–12
Between 2010 and 2012, a total of 79 time-domain electromagnetic (TEM) soundings were collected in 12 groundwater basins in the U.S. Army Fort Irwin National Training Center (NTC) study area to help improve the understanding of the hydrogeology of the NTC. The TEM data are discussed in this chapter in the context of geologic observations of the study area, the details of which are...
Authors
Matthew K. Burgess, Paul A. Bedrosian
Non-USGS Publications**
P.A. Bedrosian, M.J. Unsworth, G.D. Egbert and C.H. Thurber. 2004. Geophysical images of the creeping San Andreas Fault: Implications for the role of crustal fluids in the earthquake process, Tectonophys., 385(1-4), doi:10.1016/j.tecto.2004.02.010.
M.J. Unsworth and P.A. Bedrosian. 2004. Electrical resistivity structure at the SAFOD site from magnetotelluric exploration, Geophys. Res. Lett., 31(12), doi:10.1029/2003GL019045.
M.J. Unsworth and P.A. Bedrosian. 2004. On the geoelectric structure of major strike-slip faults and shear zones., Earth, Planets and Space, 56, 1177–1184, doi:10.1186/BF03353337.
M.J. Unsworth, W. Wenbo, A. G. Jones, S. Li, P.A. Bedrosian, J. Booker, J. Sheng, D. Ming and T. Handong. 2004. Crustal and upper mantle structure of Northern Tibet imaged with magnetotelluric data, J. Geophys. Res., 109, doi:10.1029/2002JB002305.
P.A. Bedrosian, M.J. Unsworth and G.D. Egbert. 2002. Magnetotelluric imaging of the creeping segment of the San Andreas Fault near Hollister, Geophys. Res. Lett., 29(11), 1506, doi:10.1029/2001GL014119.
M. Unsworth, O.C. Enriquez, S. Belmonte, J. Arzate and P.A. Bedrosian. 2002. Crustal structure of the Chicxulub Impact Crater imaged with magnetotelluric exploration, Geophys. Res. Lett., 29(16), 1788, doi:10.1029/2002GL014998.
P.A. Bedrosian, M.J. Unsworth and F. Wang. 2001. Structure of the Altyn Tagh Fault and Daxue Shan from magnetotelluric surveys: Implications for faulting associated with the rise of the Tibetan Plateau, Tectonics, 20, 474-486, doi:10.1029/2000TC001215.
W. Wenbo, M. Unsworth, A. Jones, J. Booker, H. Tan, D. Nelson, L. Chen, S. Li, K. Solon, P.A. Bedrosian, S. Jin, M. Deng, J. Ledo, D. Kay and B. Roberts. 2001. Widespread fluids in the Tibetan Crust, Science, 292(5517), 716-718, doi:10.1126/science.1010580.
M. Unsworth, P.A. Bedrosian, M. Eisel, G. Egbert and W. Siripunvaraporn. 2000. Along-strike variations in the electrical structure of the San Andreas Fault at Parkfield, California, Geophys. Res. Lett., 27(18), 3021-3024, doi:10.1029/2000GL011476.
**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.
*Disclaimer: Listing outside positions with professional scientific organizations on this Staff Profile are for informational purposes only and do not constitute an endorsement of those professional scientific organizations or their activities by the USGS, Department of the Interior, or U.S. Government