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.
Paul A Bedrosian
Biography
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 mineral-resource investigations, the magmatic/hydrothermal systems of active volcanoes and the importance of solid-earth conductivity to space-weather hazards.
Education
- 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
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
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
Affiliations
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2010-present, Summer of Applied Geophysical Experience (faculty)
Professional Societies
- American Geophysical Union
- Geological Society of America
Academic and Professional Service
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2018-present, Earth, Planets and Space Journal (editor)
Science and Products
Year Published: 2016
A comparison of helicopter-borne electromagnetic systems for hydrogeologic studies
The increased application of airborne electromagnetic surveys to hydrogeological studies is driving a demand for data that can consistently be inverted for accurate subsurface resistivity structure from the near surface to depths of several hundred metres. We present an evaluation of three commercial airborne electromagnetic systems over two test...
Bedrosian, Paul A.; Schamper, Cyril; Auken, EsbenAttribution: Geology, Minerals, Energy, and Geophysics Science Center, Geology, Geophysics, and Geochemistry Science Center, Region 7: Upper Colorado Basin
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Bedrosian, P. A., Schamper, C. and Auken, E. (2016), A comparison of helicopter-borne electromagnetic systems for hydrogeologic studies. Geophysical Prospecting, 64: 192–215.
Year Published: 2015
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—...
Bedrosian, Paul A.; Love, Jeffrey J.
Year Published: 2015
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...
Blum, Cletus; Love, Jeffrey J.; Pedrie, Kolby; Bedrosian, Paul A.; Rigler, E. JoshuaAttribution: Geologic Hazards Science Center, Natural Hazards, Geomagnetism Program, Region 7: Upper Colorado Basin
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Blum, Cletus, Love, J.J., Pedrie, Kolby, Bedrosian, P.A., and Rigler, E.J., 2015, A one-dimensional model of solid-Earth electrical resistivity beneath Florida: U.S. Geological Survey Open-File Report 2015–1185, 16 p., http://dx.doi.org/10.3133/ofr20151185.
Year Published: 2015
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...
Baldridge, W. S.; Bedrosian, Paul A.; Biehler, Shawn; Braile, L.W.; Ferguson, John; Folsom, Matthew; Jiracek, G.R.; Kelley, Shari A.; McPhee, Darcy K.; Pellerin, Louise; Snelson, Catherine M.
Year Published: 2015
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...
Finn, Carol A.; Bedrosian, Paul A.; Cole, Janine; Khoza, Tshepo David; Webb, Susan J.Attribution: Geology, Minerals, Energy, and Geophysics Science Center, Geology, Geophysics, and Geochemistry Science Center, Region 7: Upper Colorado Basin
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Finn, Carol A., Paul Bedrosian, Janine Cole, Tshepo David Khoza and Susan J. Webb, 2015, Mapping the extent of the Northern Lobe of the Bushveld layered mafic intrusion from geophysical data: Precambrian Research, v. 268, p. 279-294.
Year Published: 2015
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...
Ball, Lyndsay B.; Bloss, Benjamin R.; Bedrosian, Paul A.; Grauch, V.J.S.; Smith, Bruce D.Attribution: Geology, Minerals, Energy, and Geophysics Science Center, Geology, Geophysics, and Geochemistry Science Center, Region 7: Upper Colorado Basin
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Ball, L.B., Bloss, B.R., Bedrosian, P.A., Grauch, V.J.S., and Smith, B.D., 2015, Airborne electromagnetic and magnetic survey data of the Paradox and San Luis Valleys, Colorado: U.S. Geological Survey Open-File Report 2015–1024, 19 p., http://dx.doi.org/10.3133/ofr20151024.
Year Published: 2015
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...
Buesch, David C.; Bloss, Benjamin R.; Bedrosian, Paul A.Attribution: Geology, Minerals, Energy, and Geophysics Science Center, Energy and Minerals, Energy Resources Program, Mineral Resources Program, National Laboratories Program, Science and Decisions Center, Groundwater and Streamflow Information Program
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Bloss, B.R., and Bedrosian, P.A, 2015, Laboratory electrical resistivity analysis of geologic samples from Fort Irwin, California, chap. E of Buesch, D.C., ed., Geology and geophysics applied to groundwater hydrology at Fort Irwin, California: U.S. Geological Survey Open-file Report 2013-1024, 104 p., https://doi.org/10.3133/ofr20131024E.
Year Published: 2015
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...
Bennington, Ninfa L.; Zhang, Haijiang; Thurber, Cliff; Bedrosian, Paul A.
Year Published: 2014
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...
Buesch, David C.; Burgess, Matthew K.; Bedrosian, Paul A.Attribution: Geology, Minerals, Energy, and Geophysics Science Center, Energy and Minerals, Energy Resources Program, Mineral Resources Program, National Laboratories Program, Science and Decisions Center, Groundwater and Streamflow Information Program
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Burgess, M.K., and Bedrosian, P.A., 2014, Time-domain electromagnetic surveys at Fort Irwin, San Bernardino County, California, 2010–12, chap. F of Buesch, D.C., ed., Geology and geophysics applied to groundwater hydrology at Fort Irwin, California: U.S. Geological Survey Open-File Report 2013–1024, 64 p., https://doi.org/10.3133/ofr20131024F.
Year Published: 2014
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...
Buesch, David C.; Bedrosian, Paul A.; Ball, Lyndsay B.; Bloss, Benjamin R.Attribution: Geology, Minerals, Energy, and Geophysics Science Center, Energy and Minerals, Energy Resources Program, Mineral Resources Program, National Laboratories Program, Science and Decisions Center, Groundwater and Streamflow Information Program
View Citation
Bedrosian, P.A., Ball, L.B., and Bloss, B.R., 2014, Airborne electromagnetic data and processing within Leach Lake Basin, Fort Irwin, California, chap. G of Buesch, D.C., ed., Geology and geophysics applied to groundwater hydrology at Fort Irwin, California: U.S. Geological Survey Open File Report 2013–1024, 20 p.,
https://doi.org/10.3133/ofr20131024G.
Year Published: 2014
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...
Bedrosian, Paul A.; Feucht, Daniel W.Attribution: Geology, Minerals, Energy, and Geophysics Science Center, Geology, Geophysics, and Geochemistry Science Center, Region 7: Upper Colorado Basin
View Citation
Paul A. Bedrosian, Daniel W. Feucht, Structure and tectonics of the northwestern United States from EarthScope USArray magnetotelluric data,
Earth and Planetary Science Letters, Volume 402, 2014, Pages 275-289, ISSN 0012-821X
Year Published: 2014
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...
Glen, Jonathan M.G.; McPhee, Darcy K.; Bedrosian, Paul A.Pre-USGS Publications
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.