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
Geoelectric hazard maps for the continental United States
Acquisition of a unique onshore/offshore geophysical and geochemical dataset in the Northern Malawi (Nyasa) Rift
Highly conductive horizons in the Mesoproterozoic Belt-Purcell Basin: Sulfidic early basin strata as key markers of Cordilleran shortening and Eocene extension
Making it and breaking it in the Midwest: Continental assembly and rifting from modeling of EarthScope magnetotelluric data
A comparison of helicopter-borne electromagnetic systems for hydrogeologic studies
Mapping geoelectric fields during magnetic storms: Synthetic analysis of empirical United States impedances
A one-dimensional model of solid-earth electrical resistivity beneath Florida
Summer of Applied Geophysical Experience (SAGE): Training for our future geoscientists
Mapping the 3-D extent of the Northern Lobe of the Bushveld layered mafic intrusion from geophysical data
Airborne electromagnetic and magnetic survey data of the Paradox and San Luis Valleys, Colorado
Laboratory electrical resistivity analysis of geologic samples from Fort Irwin, California
Joint inversion of seismic and magnetotelluric data in the Parkfield Region of California using the normalized cross-gradient constraint
Non-USGS Publications**
**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
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Filter Total Items: 76
Geoelectric hazard maps for the continental United States
In support of a multiagency project for assessing induction hazards, we present maps of extreme-value geoelectric amplitudes over about half of the continental United States. These maps are constructed using a parameterization of induction: estimates of Earth surface impedance, obtained at discrete geographic sites from magnetotelluric survey data, are convolved with latitude-dependent statisticalAuthorsJeffrey J. Love, Antti Pulkkinen, Paul A. Bedrosian, Seth Jonas, Anna Kelbert, Erin (Josh) Rigler, Carol Finn, Christopher Balch, Robert Rutledge, Richard Waggel, Andrew Sabata, Janet Kozyra, Carrie BlackAcquisition of a unique onshore/offshore geophysical and geochemical dataset in the Northern Malawi (Nyasa) Rift
The Study of Extension and maGmatism in Malawi aNd Tanzania (SEGMeNT) project acquired a comprehensive suite of geophysical and geochemical datasets across the northern Malawi (Nyasa) rift in the East Africa rift system. Onshore/offshore active and passive seismic data, long‐period and wideband magnetotelluric data, continuous Global Positioning System data, and geochemical samples were acquired bAuthorsDonna J. Shillington, J. B. Gaherty, Cynthia J. Ebinger, Christopher A. Scholz, Kate Selway, Andrew A. Nyblade, Paul A. Bedrosian, Cornelia Class, Scott Nooner, Matthew E. Pritchard, Julie L. Elliott, Patrick R. N. Chindandali, Gaby Mbogoni, Richard Wambura Ferdinand, Nelson Boniface, Shukrani Manya, Godson Kamihanda, Elifuraha Saria, Gabriel Mulibo, Jalf Salima, Abdul Mruma, Leonard Kalindekafe, Natalie J. Accardo, Ntambila Daud, Marsella Kachingwe, Gary T. Mesko, Tannis McCartney, Melania Maquay, J. P. O'Donnell, Gabrielle Tepp, Khalfan Mtelela, Per Trinhammer, Douglas Wood, Ernest Aaron, Mark Gibaud, Martin Rapa, Cathy Pfeifer, Felix Mphepo, Duncan Gondwe, Gabriella Arroyo, Celia EddyHighly conductive horizons in the Mesoproterozoic Belt-Purcell Basin: Sulfidic early basin strata as key markers of Cordilleran shortening and Eocene extension
We investigated the crustal structure of the central Mesoproterozoic Belt Basin in northwestern Montana and northern Idaho using a crustal resistivity section derived from a transect of new short- and long-period magnetotelluric (MT) stations. Two- and three-dimensional resistivity models were generated from these data in combination with data collected previously along three parallel short-periodAuthorsPaul A. Bedrosian, Stephen E. BoxMaking it and breaking it in the Midwest: Continental assembly and rifting from modeling of EarthScope magnetotelluric data
A three-dimensional lithospheric-scale resistivity model of the North American mid-continent has been estimated based upon EarthScope magnetotelluric data. Details of the resistivity model are discussed in relation to lithospheric sutures, defined primarily from aeromagnetic and geochronologic data, which record the southward growth of the Laurentian margin in the Proterozoic. The resistivity signAuthorsPaul A. BedrosianA 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 blocks in western Nebraska, USA. The selected testAuthorsPaul A. Bedrosian, Cyril Schamper, Esben AukenMapping 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 induced by a geoAuthorsPaul A. Bedrosian, Jeffrey J. LoveA 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 responsesAuthorsCletus Blum, Jeffrey J. Love, Kolby Pedrie, Paul A. Bedrosian, E. Joshua RiglerSummer 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. Programs suchAuthorsW. 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. SnelsonMapping 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 constrains the mAuthorsCarol A. Finn, Paul A. Bedrosian, Janine Cole, Tshepo David Khoza, Susan J. WebbAirborne 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-field infAuthorsLyndsay B. Ball, Benjamin R. Bloss, Paul A. Bedrosian, V. J. S. Grauch, Bruce D. SmithLaboratory 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 plutonic aAuthorsBenjamin R. Bloss, Paul A. BedrosianJoint 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-gradient constraiAuthorsNinfa L. Bennington, Haijiang Zhang, Cliff Thurber, Paul A. BedrosianNon-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.
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*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