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: 2011
Correlation between deep fluids, tremor and creep along the central San Andreas fault
The seismicity pattern along the San Andreas fault near Parkfield and Cholame, California, varies distinctly over a length of only fifty kilometres. Within the brittle crust, the presence of frictionally weak minerals, fault-weakening high fluid pressures and chemical weakening are considered possible causes of an anomalously weak fault northwest...
Becken, M.; Ritter, O.; Bedrosian, P.A.; Weckmann, U.Attribution: Geology, Minerals, Energy, and Geophysics Science Center, Geology, Geophysics, and Geochemistry Science Center, Region 7: Upper Colorado Basin
View Citation
Correlation between deep fluids, tremor and creep along the central San Andreas fault; 2011; Article; Journal; Nature; Becken, M.; Ritter, O.; Bedrosian, P. A.; Weckmann, U.
Year Published: 2011
Shallow lithological structure across the Dead Sea Transform derived from geophysical experiments
In the framework of the DEad SEa Rift Transect (DESERT) project a 150 km magnetotelluric profile consisting of 154 sites was carried out across the Dead Sea Transform. The resistivity model presented shows conductive structures in the western section of the study area terminating abruptly at the Arava Fault. For a more detailed analysis we...
Stankiewicz, J.; Munoz, G.; Ritter, O.; Bedrosian, P.A.; Ryberg, T.; Weckmann, U.; Weber, M.Attribution: Geology, Minerals, Energy, and Geophysics Science Center, Geology, Geophysics, and Geochemistry Science Center, Region 7: Upper Colorado Basin
View Citation
Shallow lithological structure across the Dead Sea Transform derived from geophysical experiments; 2011; Article; Journal; Geochemistry, Geophysics, Geosystems; Stankiewicz, J.; Munoz, G.; Ritter, O.; Bedrosian, P. A.; Ryberg, T.; Weckmann, U.; Weber, M.
Year Published: 2010
Using airborne geophysical surveys to improve groundwater resource management models
Increasingly, groundwater management requires more accurate hydrogeologic frameworks for groundwater models. These complex issues have created the demand for innovative approaches to data collection. In complicated terrains, groundwater modelers benefit from continuous high‐resolution geologic maps and their related hydrogeologic‐parameter...
Abraham, Jared D.; Cannia, James C.; Peterson, Steven M.; Smith, Bruce D.; Minsley, Burke J.; Bedrosian, Paul A.Attribution: Geology, Minerals, Energy, and Geophysics Science Center, Geology, Geophysics, and Geochemistry Science Center, Region 7: Upper Colorado Basin
View Citation
Jared D. Abraham, James C. Cannia, Steven M. Peterson, Bruce D. Smith, Burke J. Minsley, and Paul A. Bedrosian (2010) Using Airborne Geophysical Surveys to Improve Groundwater Resource Management Models. Symposium on the Application of Geophysics to Engineering and Environmental Problems 2010: pp. 309-314.
Year Published: 2009
Anatomy of the dead sea transform from lithospheric to microscopic scale
Fault zones are the locations where motion of tectonic plates, often associated with earthquakes, is accommodated. Despite a rapid increase in the understanding of faults in the last decades, our knowledge of their geometry, petrophysical properties, and controlling processes remains incomplete. The central questions addressed here in our study of...
Weber, M.; Abu-Ayyash, K.; Abueladas, A.; Agnon, A.; Alasonati-Tasarova, Z.; Al-Zubi, H.; Babeyko, A.; Bartov, Y.; Bauer, K.; Becken, M.; Bedrosian, P.A.; Ben-Avraham, Z.; Bock, G.; Bohnhoff, M.; Bribach, J.; Dulski, P.; Ebbing, J.; El-Kelani, R.; Forster, A.; Forster, H.-J.; Frieslander, U.; Garfunkel, Z.; Goetze, H.J.; Haak, V.; Haberland, C.; Hassouneh, M.; Helwig, S.; Hofstetter, A.; Hoffmann-Rotrie, A.; Jackel, K.H.; Janssen, C.; Jaser, D.; Kesten, D.; Khatib, M.; Kind, R.; Koch, O.; Koulakov, I.; Laske, Gabi; Maercklin, N.; Masarweh, R.; Masri, A.; Matar, A.; Mechie, J.; Meqbel, N.; Plessen, B.; Moller, P.; Mohsen, A.; Oberhansli, R.; Oreshin, S.; Petrunin, A.; Qabbani, I.; Rabba, I.; Ritter, O.; Romer, R.L.; Rumpker, G.; Rybakov, M.; Ryberg, T.; Saul, J.; Scherbaum, F.; Schmidt, S.; Schulze, A.; Sobolev, S.V.; Stiller, M.; Stromeyer, D.; Tarawneh, K.; Trela, C.; Weckmann, U.; Wetzel, U.; Wylegalla, K.View Citation
Anatomy of the dead sea transform from lithospheric to microscopic scale; 2009; Article; Journal; Reviews of Geophysics; Weber, M.; Abu-Ayyash, K.; Abueladas, A.; Agnon, A.; Alasonati-Tasarova, Z.; Al-Zubi, H.; Babeyko, A.; Bartov, Y.; Bauer, K.; Becken, M.; Bedrosian, P. A.; Ben-Avraham, Z.; Bock, G.; Bohnhoff, M.; Bribach, J.; Dulski, P.; Ebbing, J.; El-Kelani, R.; Forster, A.; Forster, H. -J.; Frieslander, U.; Garfunkel, Z.; Goetze, H. J.; Haak, V.; Haberland, C.; Hassouneh, M.; Helwig, S.; Hofstetter, A.; Hoffmann-Rotrie, A.; Jackel, K. H.; Janssen, C.; Jaser, D.; Kesten, D.; Khatib, M.; Kind, R.; Koch, O.; Koulakov, I.; Laske, G.; Maercklin, N.; Masarweh, R.; Masri, A.; Matar, A.; Mechie, J.; Meqbel, N.; Plessen, B.; Moller, P.; Mohsen, A.; Oberhansli, R.; Oreshin, S.; Petrunin, A.; Qabbani, I.; Rabba, I.; Ritter, O.; Romer, R. L.; Rumpker, G.; Rybakov, M.; Ryberg, T.; Saul, J.; Scherbaum, F.; Schmidt, S.; Schulze, A.; Sobolev, S. V.; Stiller, M.; Stromeyer, D.; Tarawneh, K.; Trela, C.; Weckmann, U.; Wetzel, U.; Wylegalla, K.
Year Published: 2009
Joint inversion for Vp, Vs, and Vp/Vs at SAFOD, Parkfield, California
We refined the three-dimensional (3-D) Vp, Vs and Vp/Vs models around the San Andreas Fault Observatory at Depth (SAFOD) site using a new double-difference (DD) seismic tomography code (tomoDDPS) that simultaneously solves for earthquake locations and all three velocity models using both absolute and differential P, S, and S-P times. This new...
Zhang, H.; Thurber, C.; Bedrosian, P.View Citation
Joint inversion for Vp, Vs, and Vp/Vs at SAFOD, Parkfield, California; 2009; Article; Journal; Geochemistry, Geophysics, Geosystems; Zhang, H.; Thurber, C.; Bedrosian, P.
Year Published: 2008
A deep crustal fluid channel into the San Andreas Fault system near Parkfield, California
Magnetotelluric (MT) data from 66 sites along a 45-km-long profile across the San Andreas Fault (SAF) were inverted to obtain the 2-D electrical resistivity structure of the crust near the San Andreas Fault Observatory at Depth (SAFOD). The most intriguing feature of the resistivity model is a steeply dipping upper crustal high-conductivity zone...
Becken, M.; Ritter, O.; Park, S.K.; Bedrosian, P.A.; Weckmann, U.; Weber, M.View Citation
A deep crustal fluid channel into the San Andreas Fault system near Parkfield, California; 2008; Article; Journal; Geophysical Journal International; Becken, M.; Ritter, O.; Park, S. K.; Bedrosian, P. A.; Weckmann, U.; Weber, M.
Year Published: 2007
Hydrothermal circulation at Mount St. Helens determined by self-potential measurements
The distribution of hydrothermal circulation within active volcanoes is of importance in identifying regions of hydrothermal alteration which may in turn control explosivity, slope stability and sector collapse. Self-potential measurements, indicative of fluid circulation, were made within the crater of Mount St. Helens in 2000 and 2001. A strong...
Bedrosian, Paul A.; Unsworth, Martyn J.; Johnston, Malcolm J. S.Attribution: Natural Hazards, Volcano Hazards Program Office
Year Published: 2007
Lithology-derived structure classification from the joint interpretation of magnetotelluric and seismic models
Magnetotelluric and seismic methods provide complementary information about the resistivity and velocity structure of the subsurface on similar scales and resolutions. No global relation, however, exists between these parameters, and correlations are often valid for only a limited target area. Independently derived inverse models from these...
Bedrosian, P.A.; Maercklin, N.; Weckmann, U.; Bartov, Y.; Ryberg, T.; Ritter, O.View Citation
Lithology-derived structure classification from the joint interpretation of magnetotelluric and seismic models; 2007; Article; Journal; Geophysical Journal International; Bedrosian, P. A.; Maercklin, N.; Weckmann, U.; Bartov, Y.; Ryberg, T.; Ritter, O.
Year Published: 2007
MT+, integrating magnetotellurics to determine earth structure, physical state, and processes
As one of the few deep-earth imaging techniques, magnetotellurics provides information on both the structure and physical state of the crust and upper mantle. Magnetotellurics is sensitive to electrical conductivity, which varies within the earth by many orders of magnitude and is modified by a range of earth processes. As with all geophysical...
Bedrosian, P.A.View Citation
MT+, integrating magnetotellurics to determine earth structure, physical state, and processes; 2007; Conference Paper; Surveys in Geophysics; Bedrosian, P. A.
Year Published: 2005
Electrical conductivity images of active and fossil fault zones
We compare recent magnetotelluric investigations of four large fault systems: (i) the actively deforming, ocean-continent interplate San Andreas Fault (SAF); (ii) the actively deforming, continent-continent interplate Dead Sea Transform (DST); (iii) the currently inactive, trench-linked intraplate West Fault (WF) in northern Chile; and (iv) the...
Ritter, O.; Hoffmann-Rothe, A.; Bedrosian, Paul A.; Weckmann, U.; Haak, V.
Year Published: 2005
Characterizing a large shear-zone with seismic and magnetotelluric methods: The case of the Dead Sea Transform
Seismic tomography, imaging of seismic scatterers, and magnetotelluric soundings reveal a sharp lithologic contrast along a ???10 km long segment of the Arava Fault (AF), a prominent fault of the southern Dead Sea Transform (DST) in the Middle East. Low seismic velocities and resistivities occur on its western side and higher values east of it,...
Maercklin, N.; Bedrosian, P.A.; Haberland, C.; Ritter, O.; Ryberg, T.; Weber, M.; Weckmann, U.View Citation
Characterizing a large shear-zone with seismic and magnetotelluric methods: The case of the Dead Sea Transform; 2005; Article; Journal; Geophysical Research Letters; Maercklin, N.; Bedrosian, P. A.; Haberland, C.; Ritter, O.; Ryberg, T.; Weber, M.; Weckmann, U.
Year Published: 2005
Crustal rheology of the Himalaya and Southern Tibet inferred from magnetotelluric data
The Cenozoic collision between the Indian and Asian continents formed the Tibetan plateau, beginning about 70 million years ago. Since this time, at least 1,400 km of convergence has been accommodated by a combination of underthrusting of Indian and Asian lithosphere, crustal shortening, horizontal extrusion and lithospheric delamination. Rocks...
Unsworth, M.J.; Jones, A.G.; Wei, W.; Marquis, G.; Gokarn, S.G.; Spratt, J.E.; Bedrosian, P.; Booker, J.; Leshou, C.; Clarke, G.; Shenghui, L.; Chanhong, L.; Ming, D.; Sheng, J.; Solon, K.; Handong, T.; Ledo, J.; Roberts, B.View Citation
Crustal rheology of the Himalaya and Southern Tibet inferred from magnetotelluric data; 2005; Article; Journal; Nature; Unsworth, M. J.; Jones, A. G.; Wei, W.; Marquis, G.; Gokarn, S. G.; Spratt, J. E.; Bedrosian, P.; Booker, J.; Leshou, C.; Clarke, G.; Shenghui, L.; Chanhong, L.; Ming, D.; Sheng, J.; Solon, K.; Handong, T.; Ledo, J.; Roberts, B.
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.