A5084221478- Geophysical and Geoelectrical Methods
- Earthquake Detection and Analysis
- Seismic Waves and Analysis
- Geochemistry and Geologic Mapping
- Geomagnetism and Paleomagnetism Studies
- Geological and Geochemical Analysis
- High-pressure geophysics and materials
- earthquake and tectonic studies
- Ionosphere and magnetosphere dynamics
- Geophysical Methods and Applications
- Molecular Spectroscopy and Structure
- Geological and Geophysical Studies
- Geology and Paleoclimatology Research
- Geotechnical and Geomechanical Engineering
- Seismic Imaging and Inversion Techniques
- Advanced Chemical Physics Studies
- Geological formations and processes
- Geophysics and Gravity Measurements
- Geophysics and Sensor Technology
- Spectroscopy and Laser Applications
- Geological Studies and Exploration
- NMR spectroscopy and applications
- Economic Development and Digital Transformation
- Water Quality and Resources Studies
- Paleontology and Stratigraphy of Fossils
United States Geological Survey
2020-2024
Geology, Geophysics, and Geochemistry Science Center
2022-2024
Oregon State University
2014-2020
Pomona College
2011-2016
Scripps Institution of Oceanography
2014
University of San Diego
2014
St. Francis Xavier University
2007
Albert B. Chandler Hospital
2006
Edison International (United States)
1941
In its 18-year lifetime, the United States Magnetotelluric Array (USMTArray) has acquired more than 1,700 long-period magnetotelluric (MT) stations covering entirety of contiguous States. Funding from multiple federal agencies sustained this effort to completion in 2024. Important components project included active guidance and participation scientific community, open timely availability all data, application consistent instrumentation robust data processing. Together with parallel...
The use of daptomycin has been associated with an elevation in creatine phosphokinase level, a reported incidence 2.8% phase III clinical trials. Published case reports have documented the presence myopathy patients who received daptomycin; however, there no previously cases rhabdomyolysis animals or humans to date. We describe during therapy daptomycin.
Abstract A study is made of the relations between geomagnetic and geoelectric field variation, Earth‐surface impedance, operational interference (“anomalies”) experienced on electric‐power systems across contiguous United States during 13–14 March, 1989, magnetic storm. For this, a 1‐min‐resolution sequence maps constructed from magnetometer time series acquired at ground‐based observatories. Induced are calculated by convolving with magnetotelluric impedance tensors. During storm, anomalies...
Abstract Intense geoelectric fields during geomagnetic storms drive geomagnetically induced currents in power grids and other infrastructure, yet there are limited direct measurements of these storm‐time fields. Moreover, most previous studies examining focused on single events or small geographic regions, making it difficult to determine the typical source(s) intense We perform first comparative analysis (a) sources over multiple storms, (b) using 1‐s cadence field made at (c)...
Pure rotational spectra of the ground electronic-vibrational ${X}_{1}$ state ${}^{204}$Pb${}^{19}$F, ${}^{206}$Pb${}^{19}$F, ${}^{207}$Pb${}^{19}$F, and ${}^{208}$Pb${}^{19}$F are measured with a resonator pulsed supersonic jet Fourier-transform microwave spectrometer. Also reported is new measurement Stark effect on optical $A\ensuremath{\leftarrow}{X}_{1}$ transitions. These combined published high-resolution infrared ${X}_{2}\ensuremath{\leftrightarrow}{X}_{1}$ transitions in order to...
The magnetotelluric (MT) method for imaging the electrical conductivity structure of Earth is based on assumption that source magnetic fields can be considered quasi-uniform, such spatial scale inducing much larger than intrinsic length electromagnetic induction process (the skin depth). Here, we show using EarthScope MT data short from geomagnetic pulsations (Pc's) violate this fundamental assumption. Over resistive regions Earth, depth comparable to meridional range Pc3-4 disturbances are...
Abstract The intensification of the fluctuating geomagnetic field during space weather events leads to generation a strong electric in conducting earth, which drives geomagnetically induced currents (GICs) grounded technological systems. GICs can severely affect functioning such infrastructure. ability realistically model ground (GEF) is important for understanding impact on We present results three‐dimensional (3‐D) modeling GEF eastern United States storm March 2015. external source...
Magnetotelluric (MT) imaging results from mineral provinces in Australia and the United States show an apparent spatial relationship between crustal-scale electrical conductivity anomalies major magmatic-hydrothermal iron oxide-apatite/iron oxide-copper-gold (IOA-IOCG) deposits. Although these observations have driven substantial interest use of MT data to image ancient fluid pathways, exact cause has been unclear. Here, we interpret conductors be result graphite precipitation CO2-rich...
Abstract Geomagnetic perturbations ( B G E O ) related to magnetospheric ultralow frequency (ULF) waves induce electric fields within the conductive Earth—geoelectric )—that in turn drive geomagnetically induced currents. Though numerous past studies have examined ULF wave from a space weather perspective, few linked with . Using recently available magnetotelluric impedance and measurements contiguous United States, we explore relationship between We use satellite, ground‐based radar, , case...
Abstract At present, the most reliable information for inferring storm‐time ground electric fields along electrical transmission lines comes from coarsely sampled, national‐scale magnetotelluric (MT) data sets, such as that provided by EarthScope USArray program. An underlying assumption in use of is they adequately sample spatial heterogeneity surface relationship between geomagnetic and geoelectric fields. Here, we assess degree to which density MT sampling affects hazard assessments. For...
Here we report precision microwave spectroscopy of pure rotational transitions the $^{207}\mathrm{Pb}$$^{19}\mathrm{F}$ isotopologue. We use these data to make predictions sensitivity molecule $P$-odd, $T$-even and $T$-odd effects.
Submarine cables have become a vital component of modern infrastructure, but past submarine cable natural hazard studies mostly focused on potential damage from landslides and tsunamis. A handful examine the possibility space weather effects in cables. The main purpose this study is to develop computational model, using Python , geomagnetic induction model used estimate induced voltage response disturbances. It also utilizes newly acquired knowledge magnetotelluric associated investigations...
Abstract The stress field in the eastern United States is commonly considered to be broadly uniform and due homogeneous far‐field forces; however, modern geologic indicators this region show substantial heterogeneity. Using CitcomS model stresses based on simple input density, temperature, viscosity fields, we that local isostasy key explaining intraplate southeastern States. Crustal thickness variations appear most important reproducing observations, although slightly better match observed...
Abstract Although seismic velocity and electrical conductivity are both sensitive to temperature, thermal lithosphere properties derived almost exclusively from data because is often too strongly affected by minor highly conductive phases be a reliable indicator of temperature. However, in certain circumstances, observations can provide strong constraints on mantle temperatures. In the southeastern United States (SEUS), magnetotelluric (MT) require high resistivity values (>300 Ωm) at...
Abstract Since 1995 the eruption of andesitic Soufrière Hills Volcano (SHV), Montserrat, has been studied in substantial detail. As an important contribution to this effort, Seismic Experiment with Airgunsource-Caribbean Andesitic Lava Island Precision Seismo-geodetic Observatory (SEA-CALIPSO) experiment was devised image arc crust underlying and, if possible, magma system at SHV using tomography and reflection seismology. Field operations were carried out October–December 2007, deployment...
Abstract Three-dimensional inversion of regional long-period magnetotelluric (MT) data reveals the presence two distinct sets high-conductivity belts in Precambrian basement eastern U.S. Midcontinent. One set, beneath Missouri, Illinois, Indiana, and western Ohio, is defined by northwest–southeast-oriented conductivity structures; other Kentucky, West Virginia, includes structures that are generally oriented northeast–southwest. The northwest-trending occur mainly Paleoproterozoic crust, we...
Abstract Sedimentary records from intracaldera lakes document unique interactions between volcanic and sedimentary processes hold valuable information about the geologic evolution of associated systems. Here, we present a comprehensive analysis lacustrine package within Long Valley Caldera, California, which provides new constraints on history system as well insights into development systems in general. After eruption Bishop Tuff (760 ka), resulting caldera was partially filled by large...
Abstract An analysis is made of Earth‐surface geoelectric fields and voltages on electricity transmission power‐grids induced by a late‐phase E3 nuclear electromagnetic pulse (EMP). A hypothetical scenario considered an explosion several hundred kilotons set kilometers above the eastern‐midcontinental United States. Ground‐level are estimated convolving standard parameterization geomagnetic field variation with magnetotelluric impedance tensors derived from wideband measurements acquired...
Abstract Three-dimensional magnetotelluric (MT) imaging in central Colorado reveals a set of north-striking high-conductivity tracks at lower-crustal (50–20 km) depths, with conductive finger-like structures rising off these into the middle crust (20–5 km depth). We interpret features to represent saline aqueous fluids and partial melt that are products active extensional tectonomagmatism. These conductors distributed over wider region than narrow corridor along which Rio Grande rift...
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