Jared Peacock is a research geophysicist at the Geology, Minerals, Energy, and Geophysics Science Center in Menlo Park, CA. He received his Ph.D. from the University of Adelaide and B.S. and M.S. from the Colorado School of Mines, all in geophysics. Since joining the USGS In 2013, his expertise is in magnetotellurics, focusing on characterizing volcanic, geothermal, and mineral systems in 3D.
Professional Experience
2016 - Present, Research Geophysicist, U.S. Geological Survey, Menlo Park, CA
2013 - 2016, Mendenhall Post Doc, U.S. Geological Survey, Menlo Park, CA
Education and Certifications
Ph.D., Geophysics, University of Adelaide, 2012
M.S., Geophysics, Colorado School of Mines, 2007
B.S., Geophysics, Colorado School of Mines, 2005
Science and Products
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, Congre
Magnetotelluric data across the Southern San Andreas Fault Zone, California
The Southern San Andreas fault (SSAF) poses one of the largest seismic risks in California. However, structural properties around Coachella Valley remain enigmatic. In 2019, we collected magnetotelluric soundings (MT) to help inform depth-dependent fault zone geometry, fluid content and porosity. This project was led by the Institute of Geophysics and Planetary Physics at the University of Califor
Electrical Conductance Maps of the Great Basin, USA
Images of subsurface electrical conductivity are useful for locating fluids and other electrically conductive phases at depth in the Earth. This data release presents electrical conductance maps estimated from a 3D model of the Great Basin, USA, at five different depth ranges, spanning 2 to 200 km depth. Electrical conductance is the integration of electrical conductivity in a depth range. Great B
Geophysical characterization of geothermal resources on the Umatilla Indian Reservation in northeast Oregon
During the summers of 2017 and 2020, our team collected gravity, ground magnetic (ATV and hiked traverses), paleomagnetic and rock property (density and susceptibility) data on the Umatilla Indian Reservation (UIR) in northeast Oregon to aid in characterizing subsurface stratigraphy using 2D and 3D modeling methods. This data was integrated with conductance surfaces from a 3D magnetotelluic model
Repeat Magnetotelluric Transfer Functions from the 2012 Eruption of Tongariro, New Zealand
This dataset consists of 16 repeated magnetotelluric (MT) stations collected on Mount Tongariro, New Zealand, before (2009) and after (2013) the 2012 eruption. The data were collected in same locations with similiar instruments. Preeruption and posteruption electromagnetic magnetotelluric measurements determine variation in subsurface electrical properties resulting from changes in magmatic system
Magnetotelluric Data from the Gabbs Valley Region, Nevada, 2020
This data set consists of 59 wideband magnetotelluric (MT) stations collected by the U.S. Geological Survey in July and August of 2020 as part of a 1-year project funded by the Energy Resources Program of the U.S. Geological Survey to demonstrate full crustal control on geothermal systems in the Great Basin. Each station had 5 components, 3 orthogonal magnetic induction coils and 2 horizontal orth
Metadata standards for Magnetotelluric Time Series Data
Magnetotellurics (MT) is an electromagnetic geophysical method that is sensitive to variations in subsurface electrical resistivity. Measurements of natural electric and magnetic fields are done in the time domain, where instruments can record for a couple of hours up to mulitple months resulting in data sets on the order of gigabytes. The principles of findability, accessibility, interoperabili
Snake River Plain Play Fairway Analysis Phase 2 Favorability Model (DE EE0006733)
This data release contains all digital geographic data used and produced by the Snake River Plain Play Fairway Analysis (DE EE0006733) for Phase 2 (ArcGIS shapefiles and raster files) as well as the model processing script, tables, and documentation used to generate data outputs. Phase 2 examines two subset areas of the Phase 1 study area, Mountain Home and Camas Prairie. Brief descriptions of dat
Snake River Plain Play Fairway Analysis Phase 1 Favorability Model (DE EE0006733)
This data release contains all digital geographic data used and produced by the Snake River Plain Play Fairway Analysis (DE EE0006733) for Phase 1 (ArcGIS shapefiles and raster files) as well as the model processing script, tables, and documentation used to generate data outputs. Brief descriptions of data layers are in the metadata of GIS files, greater detail is available in the Larger Work, the
Magnetotelluric data from San Pablo Bay, California
This dataset consists of 14 magnetotelluric (MT) stations collected in 2015 near San Pablo Bay, California along a east-northeast profile. The U.S. Geological Survey acquired these data to understand the fault geometry of the Hayward Fault and the Rodgers Creek Fault.
Magnetotelluric and gravity data from the Northwest Geysers, California
This dataset consists of 42 magnetotelluric (MT) stations collected in 2017 in the Northwest Geysers, CA and 534 gravity stations collected in 2017 and 2019. The U.S. Geological Survey acquired these data as part of a project to image the heat source in the Northwest Geysers. Support was from the U.S. Geological Survey's Volcano Hazards Program.
Magnetotelluric Data from Gabbs Valley, Nevada, 2017
This dataset consists of 24 magnetotelluric (MT) stations collected in 2017 in Gabbs Valley, Nevada. The U.S. Geological Survey acquired these data as part of Phase 2 of the Nevada Play Fairway Analysis Project led by the University of Nevada at Reno and funded by the Department of Energy (grant number DE-EE0006731) with support from the U.S. Geological Survey's Energy Program.
Magnetotelluric data from Mountain Pass, California, 2015
This dataset consists of 65 magnetotelluric (MT) stations collected in 2015 near Mountain Pass, California. The U.S. Geological Survey acquired these data to create a regional conductivity model near the Mountain Pass mine. This work is in support of characterizing mineral deposits.
Three-dimensional geologic map the southeastern Gabbs Valley geothermal area, Nevada
This three-dimensional (3D) geologic map displays the subsurface geology in the upper ~4 kilometers of the Earth’s crust in the southeastern Gabbs Valley geothermal area of west-central Nevada. The 3D map was constructed by integrating the results from detailed geologic mapping, 3D gravity inversion modeling, and potential-field-geophysical studies. This effort was undertaken as part of the Nevada
Filter Total Items: 15
Repeat magnetotelluric measurements to monitor The Geysers steam field in northern California
The Geysers in northern California is the world’s largest electricity generating steam field. To help understand changes in the steam reservoir, repeat magnetotelluric (MT) measurements are being collected once a year from 2021-2023. These data will be compared and modeled to provide 4-D images of changes within the reservoir. Joint inversion with passive seismic data will be done to further co
Geophysical characterization of the Northwest Geysers geothermal field, California
The Clear Lake Volcanic Field in northern California is the youngest and northern-most part of a long-lived volcanic system that has produced recent (~10 ka) eruptions. Adjacent to the Clear Lake Volcanic Field is the worlds largest energy producing geothermal field, The Geysers. The hottest part of The Geysers geothermal field is in the northwest where temperatures reach ~400 C at 3 km depth. L
Play fairway analysis in geothermal exploration: The Snake River plain volcanic province
The Snake River volcanic province (SRP) has long been considered a target for geothermal development. It overlies a thermal anomaly that extends deep into the mantle and represents one of the highest heat flow provinces in North America, but systematic exploration been hindered by lack of a conceptual model. Play Fairway Analysis (PFA) is a methodology adapted from the petroleum industry that inte
Geophysical characterization of a Proterozoic REE terrane at Mountain Pass, eastern Mojave Desert, California
Mountain Pass, California (USA), located in the eastern Mojave Desert, hosts one of the world’s richest rare earth element (REE) deposits. The REE-rich terrane occurs in a 2.5-km-wide, northwest-trending belt of Mesoproterozoic (1.4 Ga) stocks and dikes, which intrude a larger Paleoproterozoic (1.7 Ga) metamorphic block that extends ∼10 km southward from Clark Mountain to the eastern Mescal Range.
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 model includes a shallow graben beneath thin lava fiel
The 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, analysi
Geophysical Characterization of the heat source in the Northwest Geysers, California
The Geysers, in northern California, is the largest energy producing geothermal field in the world. Looking to expand capacity, the operator Calpine Corporation developed an anomalously hot (~400 °C at 2.5 km depth) part of the field in the northwest Geysers, including testing of an enhanced geothermal systems (EGS). Though the area is anomalously hot, geophysical methods have failed to adequately
Discovery of a blind geothermal system in Southern Gabbs Valley, western Nevada, through application of the play fairway analysis at multiple scales
The Great Basin region is capable of generating much greater amounts of geothermal energy than currently produced. Most geothermal resources in this region are blind, and thus favorable characteristics for geothermal activity must be synthesized and methodologies developed to discover new commercial-grade systems. The geothermal play fairway concept involves integration of multiple parameters indi
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 important in controlling magma ascent and defining
Conductivity response to intraplate deformation: Evidence for metamorphic devolatilization and crustal‐scale fluid focusing
We present two‐dimensional electrical resistivity models of two 40 km magnetotelluric (MT) profiles across the Frome Embayment to the east of the northern Flinders Ranges, South Australia. The lower crust shows low resistivity of 10 Ω m at around 30 km depth. The middle crust is dominated by resistive (>1000 Ω m) basement rocks underlying the Flinders Ranges. Adjacent to the ranges, conductive low
Three-dimensional electrical resistivity model of the hydrothermal system in Long Valley Caldera, California, from magnetotellurics
Though shallow flow of hydrothermal fluids in Long Valley Caldera, California, has been well studied, neither the hydrothermal source reservoir nor heat source has been well characterized. Here a grid of magnetotelluric data were collected around the Long Valley volcanic system and modeled in 3-D. The preferred electrical resistivity model suggests that the source reservoir is a narrow east-west e
Magnetotelluric investigation of the Vestfold Hills and Rauer Group, East Antarctica
The Vestfold Hills and Rauer Group in East Antarctica have contrasting Archean to Neoproterozoic geological histories and are believed to be juxtaposed along a suture zone that now lies beneath the Sørsdal Glacier. Exact location and age of this suture zone are unknown, as is its relationship to regional deformation associated with the amalgamation of East Gondwana. To image the suture zone, magne
Science and Products
- Science
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, Congre - Data
Magnetotelluric data across the Southern San Andreas Fault Zone, California
The Southern San Andreas fault (SSAF) poses one of the largest seismic risks in California. However, structural properties around Coachella Valley remain enigmatic. In 2019, we collected magnetotelluric soundings (MT) to help inform depth-dependent fault zone geometry, fluid content and porosity. This project was led by the Institute of Geophysics and Planetary Physics at the University of CaliforElectrical Conductance Maps of the Great Basin, USA
Images of subsurface electrical conductivity are useful for locating fluids and other electrically conductive phases at depth in the Earth. This data release presents electrical conductance maps estimated from a 3D model of the Great Basin, USA, at five different depth ranges, spanning 2 to 200 km depth. Electrical conductance is the integration of electrical conductivity in a depth range. Great BGeophysical characterization of geothermal resources on the Umatilla Indian Reservation in northeast Oregon
During the summers of 2017 and 2020, our team collected gravity, ground magnetic (ATV and hiked traverses), paleomagnetic and rock property (density and susceptibility) data on the Umatilla Indian Reservation (UIR) in northeast Oregon to aid in characterizing subsurface stratigraphy using 2D and 3D modeling methods. This data was integrated with conductance surfaces from a 3D magnetotelluic modelRepeat Magnetotelluric Transfer Functions from the 2012 Eruption of Tongariro, New Zealand
This dataset consists of 16 repeated magnetotelluric (MT) stations collected on Mount Tongariro, New Zealand, before (2009) and after (2013) the 2012 eruption. The data were collected in same locations with similiar instruments. Preeruption and posteruption electromagnetic magnetotelluric measurements determine variation in subsurface electrical properties resulting from changes in magmatic systemMagnetotelluric Data from the Gabbs Valley Region, Nevada, 2020
This data set consists of 59 wideband magnetotelluric (MT) stations collected by the U.S. Geological Survey in July and August of 2020 as part of a 1-year project funded by the Energy Resources Program of the U.S. Geological Survey to demonstrate full crustal control on geothermal systems in the Great Basin. Each station had 5 components, 3 orthogonal magnetic induction coils and 2 horizontal orthMetadata standards for Magnetotelluric Time Series Data
Magnetotellurics (MT) is an electromagnetic geophysical method that is sensitive to variations in subsurface electrical resistivity. Measurements of natural electric and magnetic fields are done in the time domain, where instruments can record for a couple of hours up to mulitple months resulting in data sets on the order of gigabytes. The principles of findability, accessibility, interoperabiliSnake River Plain Play Fairway Analysis Phase 2 Favorability Model (DE EE0006733)
This data release contains all digital geographic data used and produced by the Snake River Plain Play Fairway Analysis (DE EE0006733) for Phase 2 (ArcGIS shapefiles and raster files) as well as the model processing script, tables, and documentation used to generate data outputs. Phase 2 examines two subset areas of the Phase 1 study area, Mountain Home and Camas Prairie. Brief descriptions of datSnake River Plain Play Fairway Analysis Phase 1 Favorability Model (DE EE0006733)
This data release contains all digital geographic data used and produced by the Snake River Plain Play Fairway Analysis (DE EE0006733) for Phase 1 (ArcGIS shapefiles and raster files) as well as the model processing script, tables, and documentation used to generate data outputs. Brief descriptions of data layers are in the metadata of GIS files, greater detail is available in the Larger Work, theMagnetotelluric data from San Pablo Bay, California
This dataset consists of 14 magnetotelluric (MT) stations collected in 2015 near San Pablo Bay, California along a east-northeast profile. The U.S. Geological Survey acquired these data to understand the fault geometry of the Hayward Fault and the Rodgers Creek Fault.Magnetotelluric and gravity data from the Northwest Geysers, California
This dataset consists of 42 magnetotelluric (MT) stations collected in 2017 in the Northwest Geysers, CA and 534 gravity stations collected in 2017 and 2019. The U.S. Geological Survey acquired these data as part of a project to image the heat source in the Northwest Geysers. Support was from the U.S. Geological Survey's Volcano Hazards Program.Magnetotelluric Data from Gabbs Valley, Nevada, 2017
This dataset consists of 24 magnetotelluric (MT) stations collected in 2017 in Gabbs Valley, Nevada. The U.S. Geological Survey acquired these data as part of Phase 2 of the Nevada Play Fairway Analysis Project led by the University of Nevada at Reno and funded by the Department of Energy (grant number DE-EE0006731) with support from the U.S. Geological Survey's Energy Program.Magnetotelluric data from Mountain Pass, California, 2015
This dataset consists of 65 magnetotelluric (MT) stations collected in 2015 near Mountain Pass, California. The U.S. Geological Survey acquired these data to create a regional conductivity model near the Mountain Pass mine. This work is in support of characterizing mineral deposits. - Maps
Three-dimensional geologic map the southeastern Gabbs Valley geothermal area, Nevada
This three-dimensional (3D) geologic map displays the subsurface geology in the upper ~4 kilometers of the Earth’s crust in the southeastern Gabbs Valley geothermal area of west-central Nevada. The 3D map was constructed by integrating the results from detailed geologic mapping, 3D gravity inversion modeling, and potential-field-geophysical studies. This effort was undertaken as part of the Nevada - Multimedia
- Publications
Filter Total Items: 15
Repeat magnetotelluric measurements to monitor The Geysers steam field in northern California
The Geysers in northern California is the world’s largest electricity generating steam field. To help understand changes in the steam reservoir, repeat magnetotelluric (MT) measurements are being collected once a year from 2021-2023. These data will be compared and modeled to provide 4-D images of changes within the reservoir. Joint inversion with passive seismic data will be done to further coGeophysical characterization of the Northwest Geysers geothermal field, California
The Clear Lake Volcanic Field in northern California is the youngest and northern-most part of a long-lived volcanic system that has produced recent (~10 ka) eruptions. Adjacent to the Clear Lake Volcanic Field is the worlds largest energy producing geothermal field, The Geysers. The hottest part of The Geysers geothermal field is in the northwest where temperatures reach ~400 C at 3 km depth. LPlay fairway analysis in geothermal exploration: The Snake River plain volcanic province
The Snake River volcanic province (SRP) has long been considered a target for geothermal development. It overlies a thermal anomaly that extends deep into the mantle and represents one of the highest heat flow provinces in North America, but systematic exploration been hindered by lack of a conceptual model. Play Fairway Analysis (PFA) is a methodology adapted from the petroleum industry that inteGeophysical characterization of a Proterozoic REE terrane at Mountain Pass, eastern Mojave Desert, California
Mountain Pass, California (USA), located in the eastern Mojave Desert, hosts one of the world’s richest rare earth element (REE) deposits. The REE-rich terrane occurs in a 2.5-km-wide, northwest-trending belt of Mesoproterozoic (1.4 Ga) stocks and dikes, which intrude a larger Paleoproterozoic (1.7 Ga) metamorphic block that extends ∼10 km southward from Clark Mountain to the eastern Mescal Range.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 model includes a shallow graben beneath thin lava fielThe 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, analysiGeophysical Characterization of the heat source in the Northwest Geysers, California
The Geysers, in northern California, is the largest energy producing geothermal field in the world. Looking to expand capacity, the operator Calpine Corporation developed an anomalously hot (~400 °C at 2.5 km depth) part of the field in the northwest Geysers, including testing of an enhanced geothermal systems (EGS). Though the area is anomalously hot, geophysical methods have failed to adequatelyDiscovery of a blind geothermal system in Southern Gabbs Valley, western Nevada, through application of the play fairway analysis at multiple scales
The Great Basin region is capable of generating much greater amounts of geothermal energy than currently produced. Most geothermal resources in this region are blind, and thus favorable characteristics for geothermal activity must be synthesized and methodologies developed to discover new commercial-grade systems. The geothermal play fairway concept involves integration of multiple parameters indiCrustal 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 important in controlling magma ascent and definingConductivity response to intraplate deformation: Evidence for metamorphic devolatilization and crustal‐scale fluid focusing
We present two‐dimensional electrical resistivity models of two 40 km magnetotelluric (MT) profiles across the Frome Embayment to the east of the northern Flinders Ranges, South Australia. The lower crust shows low resistivity of 10 Ω m at around 30 km depth. The middle crust is dominated by resistive (>1000 Ω m) basement rocks underlying the Flinders Ranges. Adjacent to the ranges, conductive lowThree-dimensional electrical resistivity model of the hydrothermal system in Long Valley Caldera, California, from magnetotellurics
Though shallow flow of hydrothermal fluids in Long Valley Caldera, California, has been well studied, neither the hydrothermal source reservoir nor heat source has been well characterized. Here a grid of magnetotelluric data were collected around the Long Valley volcanic system and modeled in 3-D. The preferred electrical resistivity model suggests that the source reservoir is a narrow east-west eMagnetotelluric investigation of the Vestfold Hills and Rauer Group, East Antarctica
The Vestfold Hills and Rauer Group in East Antarctica have contrasting Archean to Neoproterozoic geological histories and are believed to be juxtaposed along a suture zone that now lies beneath the Sørsdal Glacier. Exact location and age of this suture zone are unknown, as is its relationship to regional deformation associated with the amalgamation of East Gondwana. To image the suture zone, magne