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
Date published: August 20, 2020
Status: Active Geophysics of the Midcontinent Rift Region
The Midcontinent Rift system and surrounding Precambrian rocks are known to host highly significant mineral resources. Our project objectives are to increase understanding of this system through the integration of new and legacy geophysical data with geochemical and borehole data, map the lithology and structure of PreCambrian rocks, and develop an integrated 3D geologic model of the region....
Contacts: Benjamin J Drenth, Ph.D.
Date published: July 31, 2020
Status: Active Integrated Hyperspectral, Geophysical and Geochemical Studies of Yellowstone National Park Hydrothermal Systems
We are researching the subsurface groundwater flow systems in Yellowstone and the relation of these systems to understanding the regional movement of water in a volcanic center. New geophysical data will be integrated with existing data sets from hyperspectral data from Yellowstone's thermal areas and thermal water geochemistry to help define regionally extensive mineral assemblages, the...
Contacts: JoAnn Holloway
Date published: April 20, 2020
Status: Active Development of a Flexible Multi-Channel Spatiotemporal Geophysical HDF5 Data Format Supporting FAIR
A unique opportunity for USGS to collaborate with IRIS-PASSCAL (the national seismic instrument facility) has presented itself to develop a geophysical data archive format that follows FAIR principles. IRIS-PASSCAL is extending facility to include magnetotelluric (MT) instruments prescribing the need for them to archive collected MT data by extending their existing protocol. Concurrently,...
Contacts: Anna Kelbert, Ph.D., Paul A Bedrosian
Attribution: Community for Data Integration (CDI)
Date published: October 1, 2018
Status: Completed Keeping the Lights On in North America
Realtime geoelectric maps during a magnetic storm can assist utility companies with their operations and can help power-grid managers to make decisions that may minimize the impact to their systems.
Attribution: Natural Hazards, Geomagnetism Program
Date published: May 22, 2018
Status: Completed Metallogeny and Tectonics of the Lake Clark and Neacola Mountains Region, South-central Alaska
Alaska hosts a well-documented belt of ore deposits that lies roughly parallel to the Alaska Range, beginning at the Alaska Peninsula in the southwest, continuing up through the Fairbanks Mining District in the north, and curving back into the Tintina Gold Belt on its eastern end. Known mineral prospects and occurrences include porphyry copper, intrusion-related gold, volcanogenic massive...
Contacts: Jamey Jones, Erin Todd, Ph.D.
Date published: May 8, 2018
Status: Completed Continental Scale Geophysics — Integrated Approaches to Delineate Prospective Environments for Critical Metals
Regional geophysical data that are available over continental scales such as magnetic, gravity, and magnetotelluric data can provide a foundation towards identifying and understanding the footprints and deep plumbing systems underlying these important ore systems. Our project will use continental-scale geophysical data to map the locations of deep crustal and mantle structures that may act as...
Contacts: Anne E McCafferty
Date published: December 13, 2016
Mississippi Alluvial Plain (MAP): Water Availability Study
The Mississippi Alluvial Plain is one of the most productive agricultural regions in the Nation and depends on groundwater for irrigation. The MAP area constitutes the third largest area of irrigated cropland in the United States. The area is approximately 29,000 square miles (19 million acres) and includes parts of the States...
Contacts: Wade Kress
Date published: April 30, 2018
Regional scale magnetotelluric data from the Rio Grande Rift and southern Rocky Mountains
This dataset consists of 102 magnetotelluric (MT) stations collected in 2012-2014 in the Rio Grande Rift and southern Rocky Mountains. The U.S. Geological Survey acquired these data to improve regional conductivity models of the western United States. This work is in support of studies of the effect of lithospheric modification on electrical resistivity structure and tectonic evolution of the...
Year Published: 2021
Airborne geophysical imaging of weak zones on Iliamna Volcano, Alaska: Implications for slope stability
Water‐saturated, hydrothermally altered rocks reduce the strength of volcanic edifices and increase the potential for sector collapses and far‐traveled mass flows of unconsolidated debris. Iliamna Volcano is an andesitic stratovolcano located on the western side of the Cook Inlet, ∼225 km southwest of Anchorage and is a source of repeated...
Peterson, Dana Elise; Finn, Carol A.; Bedrosian, Paul A.
Year Published: 2021
Quantifying model structural uncertainty using airborne electromagnetic data
The ability to quantify structural uncertainty in geological models that incorporate geophysical data is affected by two primary sources of uncertainty: geophysical parameter uncertainty and uncertainty in the relationship between geophysical parameters and geological properties of interest. Here, we introduce an open-source, trans-dimensional...
Minsley, Burke J.; Foks, N. Leon; Bedrosian, Paul A.
Year Published: 2020
Simultaneous observations of geoelectric and geomagnetic fields produced by magnetospheric ULF waves
Geomagnetic perturbations (BGEO) related to magnetospheric ultralow frequency (ULF) waves induce electric fields within the conductive Earth—geoelectric fields (EGEO)—that in turn drive geomagnetically induced currents. Though numerous past studies have examined ULF wave BGEO from a space weather perspective, few studies have linked ULF...
Hartinger, M. D.; Shih, X. R.; Lucas, G.; Murphy, Benjamin Scott; Kelbert, Anna; Baker, J.B.H.; Rigler, E. Joshua; Bedrosian, Paul A.
Year Published: 2020
High-resolution mapping of the freshwater-brine interface using deterministic and Bayesian inversion of airborne electromagnetic data at Paradox Valley, USA
Salt loads in the Colorado River Basin are a primary water quality concern. Natural groundwater brine discharge to the Dolores River where it passes through the collapsed salt anticline of the Paradox Valley in western Colorado is a significant source of salt to the Colorado River. An airborne electromagnetic survey of Paradox Valley has...
Ball, Lyndsay B.; Bedrosian, Paul A.; Minsley, Burke J.
Year Published: 2020
A 100-year geoelectric hazard analysis for the U.S. high-voltage power grid
A once-per-century geoelectric hazard map is created for the United States high-voltage power grid. A statistical extrapolation from 31 years of magnetic field measurements is made by identifying 84 geomagnetic storms with the Kp and Dst indices. Data from 24 geomagnetic observatories, 1079 magnetotelluric survey sites, and 17,258 transmission...
Lucas, Greg M.; Love, Jeffrey J.; Kelbert, Anna; Bedrosian, Paul A.; Rigler, E. Joshua
Year Published: 2019
Empirical estimation of natural geoelectric hazards
Geoelectric field time series can be estimated by convolving estimates of Earth‐surface impedance, such as those obtained from magnetotelluric survey measurements, with historical records of geomagnetic variation obtained at magnetic observatories. This straightforward procedure permits the mapping of geoelectric field variation during magnetic...
Love, Jeffrey J.; Bedrosian, Paul A.; Kelbert, Anna; Lucas, Greg M.
Year Published: 2019
The first 3D conductivity model of the contiguous US: Reflections on geologic structure and application to induction hazards
Estimation of ground level geoelectric fields has been identified by the National Space Weather Action Plan as a key component of assessment and mitigation of space weather impacts on critical infrastructure. Estimates of spatially and temporally variable electric fields are used to generate statistically based hazard maps and show promise toward...
Kelbert, Anna; Bedrosian, Paul A.; Murphy, Benjamin S.
Year Published: 2019
Crustal magmatism and anisotropy beneath the Arabian Shield - A cautionary tale
Volcanism in Saudi Arabia includes a historic eruption close to the holy city of Al Madinah. As part of a volcanic hazard assessment of this area, magnetotelluric (MT) data were collected to investigate the structural setting, the distribution of melt within the crust, and the mantle source of volcanism. Interpretation of a new 3‐D resistivity...
Bedrosian, Paul A.; Peacock, Jared R.; Dhary, Maher; Shareef, Adel; Feucht, D. W.; Zahran, Hani
Year Published: 2019
Lithospheric signature of late Cenozoic extension in electrical resistivity structure of the Rio Grande rift, New Mexico, USA
We present electrical resistivity models of the crust and upper mantle from two‐dimensional (2‐D) inversion of magnetotelluric (MT) data collected in the Rio Grande rift, New Mexico, USA. Previous geophysical studies of the lithosphere beneath the rift identified a low‐velocity zone several hundred kilometers wide, suggesting that the upper mantle...
Feucht, D. W.; Bedrosian, Paul A.; Sheehan, Anne F
Year Published: 2018
Extreme‐value geoelectric amplitude and polarization across the northeast United States
Maps are presented of extreme‐value geoelectric field amplitude and horizontal polarization for the Northeast United States. These maps are derived from geoelectric time series calculated for sites across the Northeast by frequency‐domain multiplication (time‐domain convolution) of 172 magnetotelluric impedance tensors, acquired during a survey,...
Love, Jeffrey J.; Lucas, Greg M.; Bedrosian, Paul A.; Kelbert, Anna
Year Published: 2018
Crustal inheritance and a top-down control on arc magmatism at Mount St Helens
In a subduction zone, the volcanic arc marks the location where magma, generated via flux melting in the mantle wedge, migrates through the crust and erupts. While the location of deep magma broadly defines the arc position, here we argue that crustal structures, identified in geophysical data from the Washington Cascades magmatic arc, are equally...
Bedrosian, Paul A.; Peacock, Jared R.; Bowles-Martinez, Esteban; Schultz, Adam; Hill, Graham
Year Published: 2018
Geoelectric hazard maps for the Pacific Northwest
Maps of extreme value, horizontal component geoelectric field amplitude are constructed for the Pacific Northwest United States (and parts of neighboring Canada). Multidecade long geoelectric field time series are calculated by convolving Earth surface impedance tensors from 71 discrete magnetotelluric survey sites across the region with...
Love, Jeffrey J.; Lucas, Greg M.; Kelbert, Anna; 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.
Date published: March 16, 2020
New Geoelectric Hazard Map Shows Potential Vulnerability to High-Voltage Power Grid for Two-Thirds of the US
The U.S. Geological Survey released a new report on geoelectric hazards for two-thirds of the contiguous U.S., spanning from the northeast to the west coast of the Nation.
Date published: March 5, 2019
New U.S. Geological Survey Report Assesses Risk of Once-Per-Century Geomagnetic Superstorm to the Northeastern United States
A new report and map published by the U.S. Geological Survey provides critical insight to electric power grid operators across the northeastern United States in the event of a once-per-century magnetic superstorm.
Date published: September 3, 2018
Scientists Discover New Clues to Mount St. Helens Unusual Location
The atypical location of Mount St. Helens may be due to geologic structures that control where deep magmas can rise through the crust, as suggested by new findings published today in Nature Geoscience.
Date published: November 3, 2016
Study to Uncover Yellowstone’s Subsurface Mysteries
New study investigates groundwater from the air
Date published: January 7, 2016
Getting Down to Earth with Space Hazards
Magnetic storms can interfere with the operation of electric power grids and damage grid infrastructure. They can also disrupt directional drilling for oil and gas, radio communications, communication satellites and GPS systems.
Attribution: Natural Hazards, Geomagnetism Program