The project focuses on the development of novel geophysical techniques that improve our ability to understand Earth's subsurface, with broad relevance to the Mineral Resources Program and the USGS Science Strategy. Our goal is to develop and maintain state-of-the art geophysical capabilities that support the diverse science needs of USGS projects that aim to meet the challenges of the 21st century by helping to improve the economic and environmental health and prosperity of people and communities across the Nation and around the world.
Science Issue and Relevance
Mineral resource studies are fundamentally subsurface studies — from the need to characterize the geological structures that host important deposits to better understanding the landscape and environmental impacts of resource development, sophisticated geophysical methods and instruments are needed. Constantly evolving modern geophysical techniques, in particular airborne geophysical methods, present new opportunities for large-scale subsurface characterization, but also require new computational tools and software algorithms that translate geophysical datasets into meaningful interpretations that can support management decisions. The Mineral Resources Program, and the USGS as a whole, has a continuing need for the development of state-of-the-art geophysical methods and instruments that have application to mineral resource and mineral environmental studies.
Methods to Address Issue
The IMAGe project focuses on the development of novel geophysical techniques that improve our ability to understand Earth's subsurface, with broad relevance to the Mineral Resources Program and the USGS Science Strategy. Our goal is to develop and maintain state-of-the-art geophysical capabilities that support the diverse science needs of USGS projects that aim to meet the challenges of the 21st century by helping to improve the economic and environmental health and prosperity of people and communities across the Nation and around the world.
The main objectives of our research include:
Frontier Geophysical Methods: Develop novel data analysis and interpretation algorithms that help maintain USGS at the forefront of airborne geophysics. Activities will include:
- develop expertise in the use of fixed-wing airborne electromagnetic (AEM) systems which are effective for regional-scale mapping activities;
- evaluating tools for the analysis of airborne induced polarization effects, a cutting-edge approach to identifying mineralized geologic targets;
- evaluating nodal seismometers for passive seismic studies and developing open source workflows to facilitate use and analysis of these data;
- evaluation of compensation and calibration methods for UAS-based aeromagnetic surveys.
Computational Geophysics: Support maintenance of existing software codes developed over many years by Geology, Geophysics, and Geochemistry Science Center (GGGSC) researchers that are used for the processing and analysis of airborne potential field and electromagnetic datasets. Develop new advanced computational capabilities including cooperation with the USGS Advanced Research Computing (ARC) group to facilitate the implementation of geophysical codes on the USGS high-performance computing cluster (Yeti). Current focus includes:
- developing new algorithms for high performance and high throughput parallel computing needs in cooperation with GGGSC researchers,
- facilitating publication of new and existing codes through the USGS Github group,
- facilitate access and use of the Yeti high-performance computing system,
- developing hdf5 and netCDF data standards for geophysical datasets, along with open source workflows to facilitate processing, visualization, and archival of datasets.
Quantitative geologic inferences from integrated geophysical methods: Many geologic mapping targets are best resolved through the use of integrated geophysical methods that are sensitive to different physical characteristics. We will continue research into methods for combined geologic interpretations using multiple geophysical methods. Examples include: models of hydrothermally altered regions based on magnetic and resistivity data collected at Mt. Iliamna, AK, and models of the Stillwater layered mafic intrusion based on gravity, magnetic, and seismic reflection data.
Uncertainty quantification: There are two fundamental sources of uncertainty in developing geological interpretations from geophysical data. First is the underlying uncertainty in geophysical properties (e.g. electrical resistivity, magnetic susceptibility, density, or seismic velocity) given a specific type of geophysical survey along with measurement errors. The second is the uncertainty in the relationship between geophysical and geological properties. We will address multiple aspects of uncertainty quantification for different types of geophysical data. Work will include:
- Continued development of GeoBIPy open source software for uncertainty quantification of airborne electromagnetic data, and extension to other data types
- Probabilistic geologic modeling to quantify the uncertainty in geological model structure given prior expert knowledge, geophysical data, and other existing observations. One application will be to investigate uncertainty in the shape and location of carbonatite deposits in the Mountain Pass project based on gravity and magnetic data. We will also build tools to quantify geological model uncertainty based on airborne electromagnetic datasets along with geostatistical simulation tools.
- An open-source toolbox for physical property relationships and uncertainty. We will develop an source software application using Python that will allow users, in a stochastic framework, to estimate physical properties such as temperature, water content, clay content, partial melt, or porosity based on geophysical parameters such as resistivity, density, or magnetic susceptibility.
Facilities
Geophysical Test Site - In 2015, we began to establish a geophysical test site at the USGS Boulder Geomagnetic Observatory. We are continuing to collect new baseline datasets for a broad suite of geophysical instruments. The test site will be used to calibrate and assess the accuracy of in-house and commercial geophysical tools, to develop and test new instrumentation, and for training Geology, Geophysics, and Geochemistry Science Center scientists and partners.
Previous Project Activities
Geophysical Instrument Development - The USGS and its Mineral Resources Program required the development of new geophysical instrumentation, and the maintenance of existing geophysical instrumentation.
Alaska Geophysical Data Processing - Alaska is a geologic frontier with substantial mineral resource potential. Complex geology, limited outcrop, and high logistical costs make airborne geophysics essential for efficient reconnaissance. We performed an advanced analysis of electromagnetic data to map geologic trends, structural geologic and tectonic patterns, and identify key lithologies for direct integration with geologic framework and mineral potential studies.
Monthly Webinar Series - We coordinated an internal, monthly webinar series to highlight cutting-edge geophysical research and applications related to our project's research, as well as other innovative work related to remote sensing and geochemistry by Geology, Geophysics, and Geochemistry Science Center scientists and other USGS colleagues.
Petrophysics Laboratory - The Petrophysics Laboratory is a multi-user facility that provides physical property data of earth materials for geophysical research. The Laboratory is equipped to make physical property measurements on rocks and sediment including density, magnetic properties, electrical properties, and radiometric properties. Knowledge of a site's physical properties is an important asset in planning geophysical surveys; particularly in selection of an appropriate method and in selecting optimum survey parameters such as array size and frequency. Knowing the range of physical properties for a given area help refine geophysical interpretations and provide justification for constraining model input parameters. The integration of physical property data with mineralogical and geochemical data provides an important link between the rocks and ores to their observed geophysical signatures.
Geophysical Instrumentation Laboratory - The Geophysical Instrumentation Laboratory provides electronic, software, and mechanical design and fabrication services for projects within the Geology, Geophysics, and Geochemistry Science Center.
- Machine shop with tools for wood, metal, plastic, and fiberglass fabrication
- Expertise with LabVIEW software for data acquisition and signal processing
- Electronic design, analysis and fabrication capability includes signal filtering, digital logic and circuit design, and more
Return to Mineral Resources Program | Geology, Geophysics, and Geochemistry Science Center
Below are other science projects associated with this project.
Integrated Hyperspectral, Geophysical and Geochemical Studies of Yellowstone National Park Hydrothermal Systems
Geophysical Research and Development
ROSETTA-Ice — Ross Ice Shelf, Antarctica
Alaska Petroleum Systems
Iron Oxide-Copper-Cobalt-Gold-Rare Earth Element Deposits of Southeast Missouri—From the Ore Deposit Scale to a Global Deposit Model
Great Basin Metallogeny and Regional Structure - New Interpretations of Magnetic and Gravity Data
Boulder (BOU)
Continental Scale Geophysics — Integrated Approaches to Delineate Prospective Environments for Critical Metals
Alaska Geophysical Survey Interpretation
Integrated Methods Development Project
Below are data or web applications associated with this project.
Airborne electromagnetic and magnetic survey data, Iliamna Volcano, Alaska, June 2012
Helicopter magnetic and gravity gradiometry survey over the Pea Ridge iron mine and surrounding area, southeast Missouri, 2014
Airborne magnetic and radiometric survey, Ironton, Missouri area
Airborne electromagnetic and magnetic survey data, East Poplar Oil Field and surrounding area, October 2014, Fort Peck Indian Reservation, Montana
Principal facts of gravity data in the southern San Luis Basin, northern New Mexico
Physical properties by geologic unit in the southern San Luis basin, New Mexico
Airborne Geophysical Surveys over the Eastern Adirondacks, New York State
Airborne Magnetic Total-Field Survey, Manchester Region, Iowa, USA
Missouri Breaks Project, Montana - Digitized aeromagnetic data
Airborne Geophysical Surveys over the 2011 Mineral, Virginia Earthquake Area
Below are publications associated with this project.
Airborne geophysical imaging of weak zones on Iliamna Volcano, Alaska: Implications for slope stability
Model structural uncertainty quantification and hydrogeophysical data integration using airborne electromagnetic data
Quantifying model structural uncertainty using airborne electromagnetic data
Three-dimensional shape and structure of the Susitna basin, south-central Alaska, from geophysical data
A 100-year geoelectric hazard analysis for the U.S. high-voltage power grid
The first 3D conductivity model of the contiguous US: Reflections on geologic structure and application to induction hazards
Crustal magmatism and anisotropy beneath the Arabian Shield - A cautionary tale
Crustal architecture beneath the southern Midcontinent (USA) and controls on Mesoproterozoic iron-oxide mineralization from 3D geophysical models
Ross Ice Shelf response to climate driven by the tectonic imprint on seafloor bathymetry
Inversion of airborne EM data with an explicit choice of prior model
The MTPy software package for magnetotelluric data analysis and visualisation
Lithospheric signature of late Cenozoic extension in electrical resistivity structure of the Rio Grande rift, New Mexico, USA
Below are software products associated with this project.
GeoBIPy – Geophysical Bayesian Inference in Python
GeoBIPy – Geophysical Bayesian Inference in Python – is an open-source algorithm for quantifying uncertainty in airborne electromagnetic (AEM) data and associated geological interpretations. This package uses a Bayesian formulation and Markov chain Monte Carlo sampling methods to derive posterior distributions of subsurface electrical resistivity based on measured AEM data.
Below are news stories associated with this project.
In addition to the USGS Geomagnetism Program and the USGS Advanced Research Computing group, below are external partners associated with this project.
- Overview
The project focuses on the development of novel geophysical techniques that improve our ability to understand Earth's subsurface, with broad relevance to the Mineral Resources Program and the USGS Science Strategy. Our goal is to develop and maintain state-of-the art geophysical capabilities that support the diverse science needs of USGS projects that aim to meet the challenges of the 21st century by helping to improve the economic and environmental health and prosperity of people and communities across the Nation and around the world.
Science Issue and Relevance
Mineral resource studies are fundamentally subsurface studies — from the need to characterize the geological structures that host important deposits to better understanding the landscape and environmental impacts of resource development, sophisticated geophysical methods and instruments are needed. Constantly evolving modern geophysical techniques, in particular airborne geophysical methods, present new opportunities for large-scale subsurface characterization, but also require new computational tools and software algorithms that translate geophysical datasets into meaningful interpretations that can support management decisions. The Mineral Resources Program, and the USGS as a whole, has a continuing need for the development of state-of-the-art geophysical methods and instruments that have application to mineral resource and mineral environmental studies.
The Interdisciplinary Methods and Applications in Geophysics (IMAGe) project supports a broad range of activities that spans instrument development and data acquisition tools, novel methods for processing geophysical datasets, uncertainty quantification, laboratory measurement of physical properties, and techniques for integrating geophysical data into interpretive geological models. Methods to Address Issue
The IMAGe project focuses on the development of novel geophysical techniques that improve our ability to understand Earth's subsurface, with broad relevance to the Mineral Resources Program and the USGS Science Strategy. Our goal is to develop and maintain state-of-the-art geophysical capabilities that support the diverse science needs of USGS projects that aim to meet the challenges of the 21st century by helping to improve the economic and environmental health and prosperity of people and communities across the Nation and around the world.
The main objectives of our research include:
Frontier Geophysical Methods: Develop novel data analysis and interpretation algorithms that help maintain USGS at the forefront of airborne geophysics. Activities will include:
- develop expertise in the use of fixed-wing airborne electromagnetic (AEM) systems which are effective for regional-scale mapping activities;
- evaluating tools for the analysis of airborne induced polarization effects, a cutting-edge approach to identifying mineralized geologic targets;
- evaluating nodal seismometers for passive seismic studies and developing open source workflows to facilitate use and analysis of these data;
- evaluation of compensation and calibration methods for UAS-based aeromagnetic surveys.
Computational Geophysics: Support maintenance of existing software codes developed over many years by Geology, Geophysics, and Geochemistry Science Center (GGGSC) researchers that are used for the processing and analysis of airborne potential field and electromagnetic datasets. Develop new advanced computational capabilities including cooperation with the USGS Advanced Research Computing (ARC) group to facilitate the implementation of geophysical codes on the USGS high-performance computing cluster (Yeti). Current focus includes:
- developing new algorithms for high performance and high throughput parallel computing needs in cooperation with GGGSC researchers,
- facilitating publication of new and existing codes through the USGS Github group,
- facilitate access and use of the Yeti high-performance computing system,
- developing hdf5 and netCDF data standards for geophysical datasets, along with open source workflows to facilitate processing, visualization, and archival of datasets.
Quantitative geologic inferences from integrated geophysical methods: Many geologic mapping targets are best resolved through the use of integrated geophysical methods that are sensitive to different physical characteristics. We will continue research into methods for combined geologic interpretations using multiple geophysical methods. Examples include: models of hydrothermally altered regions based on magnetic and resistivity data collected at Mt. Iliamna, AK, and models of the Stillwater layered mafic intrusion based on gravity, magnetic, and seismic reflection data.
Uncertainty quantification: There are two fundamental sources of uncertainty in developing geological interpretations from geophysical data. First is the underlying uncertainty in geophysical properties (e.g. electrical resistivity, magnetic susceptibility, density, or seismic velocity) given a specific type of geophysical survey along with measurement errors. The second is the uncertainty in the relationship between geophysical and geological properties. We will address multiple aspects of uncertainty quantification for different types of geophysical data. Work will include:
- Continued development of GeoBIPy open source software for uncertainty quantification of airborne electromagnetic data, and extension to other data types
- Probabilistic geologic modeling to quantify the uncertainty in geological model structure given prior expert knowledge, geophysical data, and other existing observations. One application will be to investigate uncertainty in the shape and location of carbonatite deposits in the Mountain Pass project based on gravity and magnetic data. We will also build tools to quantify geological model uncertainty based on airborne electromagnetic datasets along with geostatistical simulation tools.
- An open-source toolbox for physical property relationships and uncertainty. We will develop an source software application using Python that will allow users, in a stochastic framework, to estimate physical properties such as temperature, water content, clay content, partial melt, or porosity based on geophysical parameters such as resistivity, density, or magnetic susceptibility.
Facilities
Geophysical Test Site - In 2015, we began to establish a geophysical test site at the USGS Boulder Geomagnetic Observatory. We are continuing to collect new baseline datasets for a broad suite of geophysical instruments. The test site will be used to calibrate and assess the accuracy of in-house and commercial geophysical tools, to develop and test new instrumentation, and for training Geology, Geophysics, and Geochemistry Science Center scientists and partners.
Previous Project Activities
Geophysical Instrument Development - The USGS and its Mineral Resources Program required the development of new geophysical instrumentation, and the maintenance of existing geophysical instrumentation.
Alaska Geophysical Data Processing - Alaska is a geologic frontier with substantial mineral resource potential. Complex geology, limited outcrop, and high logistical costs make airborne geophysics essential for efficient reconnaissance. We performed an advanced analysis of electromagnetic data to map geologic trends, structural geologic and tectonic patterns, and identify key lithologies for direct integration with geologic framework and mineral potential studies.
Monthly Webinar Series - We coordinated an internal, monthly webinar series to highlight cutting-edge geophysical research and applications related to our project's research, as well as other innovative work related to remote sensing and geochemistry by Geology, Geophysics, and Geochemistry Science Center scientists and other USGS colleagues.
Petrophysics Laboratory - The Petrophysics Laboratory is a multi-user facility that provides physical property data of earth materials for geophysical research. The Laboratory is equipped to make physical property measurements on rocks and sediment including density, magnetic properties, electrical properties, and radiometric properties. Knowledge of a site's physical properties is an important asset in planning geophysical surveys; particularly in selection of an appropriate method and in selecting optimum survey parameters such as array size and frequency. Knowing the range of physical properties for a given area help refine geophysical interpretations and provide justification for constraining model input parameters. The integration of physical property data with mineralogical and geochemical data provides an important link between the rocks and ores to their observed geophysical signatures.
Geophysical Instrumentation Laboratory - The Geophysical Instrumentation Laboratory provides electronic, software, and mechanical design and fabrication services for projects within the Geology, Geophysics, and Geochemistry Science Center.
- Machine shop with tools for wood, metal, plastic, and fiberglass fabrication
- Expertise with LabVIEW software for data acquisition and signal processing
- Electronic design, analysis and fabrication capability includes signal filtering, digital logic and circuit design, and more
Return to Mineral Resources Program | Geology, Geophysics, and Geochemistry Science Center
- Science
Below are other science projects associated with this project.
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 evolution...Geophysical Research and Development
The Geophysical Research and Development Project supported the development of new and existing geophysical techniques for addressing critical geological problems. Research conducted under this project included development of needed geophysical methods and software, development of new geophysical instrumentation, and applications of geophysical techniques to frontier areas of geology.ROSETTA-Ice — Ross Ice Shelf, Antarctica
ROSETTA-Ice is a large, NSF-funded, multi-disciplinary and multi-institutional project with several major goals focused on the full ice shelf system of the Ross Ice Shelf that include the ice, underlying seafloor bathymetry, and ocean interaction. Methods include the first comprehensive LC-130-based airborne geophysical survey of the Ross Ice Shelf to measure ice thickness and accumulation (ice...Alaska Petroleum Systems
The Alaska Petroleum Systems project has three main objectives: (A) conduct research that increases our understanding of Alaska petroleum systems, (B) conduct assessments of undiscovered oil and gas resources, and (C) deliver energy-resource information to land and resource managers, policy makers, and the public.Iron Oxide-Copper-Cobalt-Gold-Rare Earth Element Deposits of Southeast Missouri—From the Ore Deposit Scale to a Global Deposit Model
The project main objectives are to: 1) geologically, characterize the setting and origin of the iron-copper-cobalt-gold-rare earth element deposits, and advance the knowledge of rare earth element and Co potential within iron oxide-copper-gold (IOCG) deposits of southeast Missouri, and 2) geophysically delineate and characterize the subsurface Precambrian geology using existing ground and new...Great Basin Metallogeny and Regional Structure - New Interpretations of Magnetic and Gravity Data
This project incorporates new geophysical technologies developed at the Tucson office of the Geology, Minerals, Energy, and Geophysics Science Center over the last 20 years for assessing mineral deposits concealed by basin sediments. These technologies include: textural classification of magnetic and magnetotelluric data and methods to characterize bedrock/basement lithologies, improved lineament...Boulder (BOU)
The Boulder observatory was established in 1963. The grounds for the observatory are overseen by the National Telecommunications and Information Administration of the Department of Commerce. This observatory is closest to Program headquarters in Golden. Therefore, in addition to serving as a site for routine data collection, Boulder also functions as the Program’s test bed for on-going operational...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...Alaska Geophysical Survey Interpretation
Available geophysical data for Alaska have not been fully exploited. Project objectives were to conduct systematic analysis of existing gravity, aeromagnetic and airborne electromagnetic data to map geologic trends, structural geologic and tectonic patterns, and identify key lithologies for direct integration with geologic framework and mineral potential studies.Integrated Methods Development Project
The Integrated Methods Development Project (IMDP) was an interdisciplinary project to develop tools and conduct research requiring integration of geologic, geophysical, geochemical, and remote-sensing expertise. - Data
Below are data or web applications associated with this project.
Airborne electromagnetic and magnetic survey data, Iliamna Volcano, Alaska, June 2012
Airborne electromagnetic (AEM) and magnetic survey data were collected during June 2012 along 556 line-kilometers over Iliamna Volcano, Alaska. These data were collected in support of alteration and volcano flank instability mapping as part of the U.S. Geological Survey (USGS) Volcano Hazards Program. Data were acquired by SkyTEM Survey ApS SkyTEM304 system with the Soloy Helicopters Eurocopter AsHelicopter magnetic and gravity gradiometry survey over the Pea Ridge iron mine and surrounding area, southeast Missouri, 2014
High resolution magnetic and gravity gradient data were collected using the HeliFalcon airborne gravity gradiometry system together with a stinger-mounted magnetometer. The survey took place out of the Sullivan, Missouri airport during March of 2014. The survey covers a 35 x 37 square-kilometer area centered on the Pea Ridge iron oxide-apatite rare-earth element deposit, which is located about halAirborne magnetic and radiometric survey, Ironton, Missouri area
This publication provides digital flight line data for a high resolution horizontal magnetic gradient and radiometric survey over the Ironton, Missouri area of southeast Missouri. Data were collected using a fixed wing aircraft with magnetometers mounted in the tail stinger and each wing tip pod and a fully calibrated gamma ray spectrometer. The survey took place out of the Farmington, Missouri aAirborne electromagnetic and magnetic survey data, East Poplar Oil Field and surrounding area, October 2014, Fort Peck Indian Reservation, Montana
Airborne electromagnetic (AEM) and magnetic survey data were collected during October 2014 in a 553-square-kilometer area that includes the East Poplar oil field on the Fort Peck Indian Reservation in northeastern Montana, USA. Data surround the town of Poplar and extend south into the Missouri River floodplain. Data were acquired with the SkyTEM301 transient electromagnetic helicopter-borne sysPrincipal facts of gravity data in the southern San Luis Basin, northern New Mexico
Gravity data were collected from 2006 through 2015 to assist in mapping subsurface geology in the southern San Luis Basin, northern New Mexico. This report gives principal facts for 567 new gravity stations that were acquired to fill in gaps in the public gravity data coverage.Physical properties by geologic unit in the southern San Luis basin, New Mexico
Physical properties of geologic units are important for geophysical interpretation because they provide the tie between lithology and geophysical fields. For gravity data, the applicable physical property is bulk density, which is the overall mass per unit volume of rocks, sediments, and their pore spaces. Bulk dry density is the mass per unit volume measured when the sample is dry. Saturated denAirborne Geophysical Surveys over the Eastern Adirondacks, New York State
Airborne geophysical surveys were conducted in the eastern Adirondacks from Dec. 7, 2015 - Dec. 21, 2015, by Goldak Airborne Surveys. The area was flown along a draped surface with a nominal survey height above ground of 200 meters. The flight line spacing was 250 meters for traverse lines and 2500 meters for control lines. Here we present downloadable magnetic and radiometric (gamma spectrometry)Airborne Magnetic Total-Field Survey, Manchester Region, Iowa, USA
This data release includes the airborne magnetic survey data collected from the Manchester region of Iowa. The Mineral Resources Program of the U.S. Geological Survey is tasked with understanding the nation's mineral resources. Precambrian rocks concealed under Paleozoic sedimentary rocks in northeast Iowa are poorly mapped and understood. Detailed high-resolution airborne magnetic surveys, groundMissouri Breaks Project, Montana - Digitized aeromagnetic data
From February 12 to March 8, 1981, EG and G Geometrics conducted an aeromagnetic survey in Montana for Anaconda Copper Company. A Piper Navajo aircraft was used to conducted the survey. The survey was flown along north-south flightlines spaced 660 feet at a nominal height of 450 feet above the terrain. Five uniformly spaced east-west tie-lines were also flown. During processing, the InternationalAirborne Geophysical Surveys over the 2011 Mineral, Virginia Earthquake Area
The 2011 moment magnitude (Mw) 5.8 central Virginia earthquake was felt by millions of people and caused significant damage in the eastern United States. As part of efforts to better understand the faults and geologic features associated with the earthquake, the U.S. Geological Survey commissioned airborne geophysical surveys over the epicentral area. Here we present the data from those surveys an - Publications
Below are publications associated with this project.
Filter Total Items: 72Airborne 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 avalanches. The widespread snow and ice cover on Iliamna VoAuthorsDana E. Peterson, Carol A. Finn, Paul A. BedrosianModel structural uncertainty quantification and hydrogeophysical data integration using airborne electromagnetic data
Airborne electromagnetic (AEM) dataare usedto estimate large-scale model structural geometry, i.e. the spatial distribution of different lithological units based on assumed or estimated resistivity-lithology relationships, and the uncertainty in those structures given imperfect measurements. Geophysically derived estimates of model structural uncertainty are then combined with hydrologic observatiAuthorsBurke J. Minsley, Nikolaj K Christensen, Steen Christensen, Yusen Ley-CooperQuantifying 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 Bayesian Markov chain Monte Carlo (McMC) algorithm GeoAuthorsBurke J. Minsley, N. Leon Foks, Paul A. BedrosianThree-dimensional shape and structure of the Susitna basin, south-central Alaska, from geophysical data
We use gravity, magnetic, seismic reflection, well, and outcrop data to determine the three-dimensional shape and structural features of south-central Alaska’s Susitna basin. This basin is located within the Aleutian-Alaskan convergent margin region and is expected to show effects of regional subduction zone processes. Aeromagnetic data, when filtered to highlight anomalies associated with sourcesAuthorsAnjana K. Shah, Jeffrey Phillips, Kristen A. Lewis, Richard G. Stanley, Peter J. Haeussler, Christopher J. PotterA 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 lines are utilized to perform a geoelectric hazardAuthorsGreg M. Lucas, Jeffrey J. Love, Anna Kelbert, Paul A. Bedrosian, E. Joshua RiglerThe 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 monitoring and responding to geomagnetic disturbancAuthorsAnna Kelbert, Paul A. Bedrosian, Benjamin S. MurphyCrustal 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 model includes a shallow graben beneath thin lava fielAuthorsPaul A. Bedrosian, Jared R. Peacock, Maher Dhary, Adel Shareef, D. W. Feucht, Hani ZahranCrustal architecture beneath the southern Midcontinent (USA) and controls on Mesoproterozoic iron-oxide mineralization from 3D geophysical models
Several types of critical mineral-bearing ore deposits in the southern Midcontinent region of the U.S. are hosted in Mesoproterozoic igneous rocks largely concealed beneath Paleozoic cover. Discerning the architecture of igneous intrusions and volcanic centers in the crust is fundamental to understanding the geologic evolution of this vast region and its mineral resources. To advance the understanAuthorsAnne E. McCafferty, Jeffrey D. Phillips, Albert H. Hofstra, Warren C. DayRoss Ice Shelf response to climate driven by the tectonic imprint on seafloor bathymetry
Ocean melting has thinned Antarctica's ice shelves at an increasing rate over the past two decades, leading to loss of grounded ice. The Ross Ice Shelf is currently close to steady state but geological records indicate that it can disintegrate rapidly, which would accelerate grounded ice loss from catchments equivalent to 11.6 m of global sea level rise. Here, we use data from the ROSETTA-Ice airAuthorsK J Tinto, L Padman, C S Siddoway, M.R. Springer, H.A. Fricker, I. Das, F. Caratori Tontini, D.F. Porter, N.P. Frearson, S. J. Howard, M.R. Siegfried, C. Mosbeux, M.K. Becker, C. Bertinato, A. Boghosian, N. Brady, Bethany L. Burton, W. Chu, S.I. Cordero, T. Dhakal, L. Dong, C.D. Gustafson, S. Keeshin, C. Locke, A. Lockett, G. O'Brien, J.J. Spergel, S.E. Starke, M. Tankersley, M. Wearing, R. E. BellInversion of airborne EM data with an explicit choice of prior model
Inversion of airborne electromagnetic (AEM) data is an under-determined inverse problem, in that infinitely many resistivity models exist that will be able to explain the observed data, within measurement errors. Therefore, additional information or constraints must be taken into account to solve the inverse problem. In deterministic approaches, the goal is to locate one optimal model that can beAuthorsThomas Mejer Hansen, Burke J. MinsleyThe MTPy software package for magnetotelluric data analysis and visualisation
The magnetotelluric (MT) method is increasingly being applied to a wide variety of geoscience problems. However, the software available for MT data analysis and interpretation is still very limited in comparison to many of the more mature geophysical methods such as the gravity, magnetic or seismic reflection methods. MTPy is an open source Python package to assist with MT data processing, analysiAuthorsAlison Kirkby, Fei Zhang, Jared R. Peacock, Rakib Hassan, Jingming DuanLithospheric 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 is characterized by a very broad zone of modifiedAuthorsD. W. Feucht, Paul A. Bedrosian, Anne F Sheehan - Software
Below are software products associated with this project.
GeoBIPy – Geophysical Bayesian Inference in Python
GeoBIPy – Geophysical Bayesian Inference in Python – is an open-source algorithm for quantifying uncertainty in airborne electromagnetic (AEM) data and associated geological interpretations. This package uses a Bayesian formulation and Markov chain Monte Carlo sampling methods to derive posterior distributions of subsurface electrical resistivity based on measured AEM data.
- News
Below are news stories associated with this project.
- Partners
In addition to the USGS Geomagnetism Program and the USGS Advanced Research Computing group, below are external partners associated with this project.