A5022389007- Atmospheric and Environmental Gas Dynamics
- Geological and Geochemical Analysis
- Hydrocarbon exploration and reservoir analysis
- Geology and Paleoclimatology Research
- Geochemistry and Geologic Mapping
- earthquake and tectonic studies
- Groundwater and Isotope Geochemistry
- CO2 Sequestration and Geologic Interactions
- Groundwater flow and contamination studies
- Methane Hydrates and Related Phenomena
- Water Quality and Resources Studies
- Soil Geostatistics and Mapping
- High-pressure geophysics and materials
- Climate change and permafrost
- Paleontology and Stratigraphy of Fossils
- Seismology and Earthquake Studies
- Isotope Analysis in Ecology
- Geothermal Energy Systems and Applications
- Landslides and related hazards
- Karst Systems and Hydrogeology
- Seismic Waves and Analysis
- Atmospheric chemistry and aerosols
- Botany, Ecology, and Taxonomy Studies
- Geological and Geophysical Studies Worldwide
- Radioactive element chemistry and processing
United States Geological Survey
2010-2023
Cascades Volcano Observatory
2023
University of California, Davis
2016-2018
Volcano Science Center
2017
Los Alamos National Laboratory
2001-2002
Stanford University
2002
Geothermal Technologies Office
2002
University of New Mexico
2000
Lawrence Livermore National Laboratory
1997
University of Missouri
1996
Subduction transports volatiles between Earth's mantle, crust, and atmosphere, ultimately creating a habitable Earth. We use isotopes to track carbon from subduction outgassing along the Aleutian-Alaska Arc. find substantial along-strike variations in isotopic composition of volcanic gases, explained by different recycling efficiencies subducting atmosphere via arc volcanism modulated character. Fast cool facilitates ~43 61% sediment-derived organic through degassing central Aleutian...
We sampled fumaroles and hot springs from the Heart Lake Geyser Basin (HLGB), measured water gas discharge, estimated heat mass flux this geothermal area in 2009. The combined data set reveals that diverse fluids share an origin by mixing of deep solute‐rich parent with dilute heated meteoric water, accompanied subsequent boiling. A variety chemical isotopic geothermometers are consistent a equilibrates rocks at 205°C ± 10°C then undergoes 21% 2% adiabatic Measured diffuse CO 2 fumarole...
This paper quantifies atmospheric mercury (Hg) emissions from substrates and fumaroles associated with three hydrothermal systems: Lassen Volcanic Center, California (LVC); Yellowstone Caldera, Wyoming (YC); Dixie Valley, Nevada (DV). Substrate Hg fluxes were measured using field chamber methods at thermal nonthermal sites. The highest (up to 541 ng m −2 h −1 ) active areas. Fluxes altered unaltered sites <10 comparable those in natural low‐Hg background regions for YC DV, LVC they...
This report presents 130 gas analyses and 31 related water on samples collected from thermal features at Yellowstone between 2003 2009. An overview of previous studies emissions is also given. The analytical results the present study include bulk chemistry gases waters isotope values for steam (delta18O, dealtaD), carbon dioxide (delta13C only), methane helium, neon, argon. We appendixes containing photos sample sites, geographic information system (GIS) files including shape kml formats, in...
Research Article| December 01, 2010 Tree-ring 14C links seismic swarm to CO2 spike at Yellowstone, USA William C. Evans; Evans * 1U.S. Geological Survey, 345 Middlefield Road, Menlo Park, California 94025, *E-mail: wcevans@usgs.gov. Search for other works by this author on: GSW Google Scholar Deborah Bergfeld; Bergfeld John P. McGeehin; McGeehin 2U.S. 12201 Sunrise Valley Drive, Reston, Virginia 20192, King; King 3Lone Pine Research, 2604 Westridge Bozeman, Montana 59715, Henry Heasler...
Abstract Ongoing (1996–present) volcanic unrest near South Sister, Oregon, is accompanied by a striking set of hydrothermal anomalies, including elevated temperatures, major ion concentrations, and 3 He/ 4 He ratios as large 8.6 R A in slightly thermal springs. These observations prompted the US Geological Survey to begin systematic hydrothermal‐monitoring effort encompassing 25 sites 10 highest‐risk volcanoes Cascade arc, from Mount Baker Canadian border Lassen Peak northern California....
The active Lassen hydrothermal system includes a central vapor-dominated zone or zones beneath the highlands underlain by ~240 °C high-chloride waters that discharge at lower elevations. It is best-exposed and largest in Cascade Range, discharging 41 ± 10 kg/s of steam (~115 MW) 23 2 (~27 MW). accounts for full 1/3 total high-temperature heat U.S. Cascades (140/400 Hydrothermal ~140 MW can be supported crystallization cooling silicic magma rate ~2400 km3/Ma, ongoing rates magmatic CO2 are...
Carbon isotope fractionations between calcite and graphite in the Panamint Mountains, California, USA, demonstrate importance of mass balance on carbon values metamorphosed carbon‐bearing minerals while recording thermal conditions during peak regional metamorphism. Interbedded graphitic marbles calcareous schists Kingston Peak Formation define distinct populations a δ 13 C (gr) –δ (cc) diagram. The both are higher than respective schists. rock types were controlled by relative proportions...
Abstract In the past two decades, U.S. Geological Survey and National Park Service have studied hydrothermal activity across Yellowstone Plateau Volcanic Field (YPVF) to improve understanding of magmatic‐hydrothermal system provide a baseline for detecting future anomalous activity. 2017 2018 we sampled water gas over large area in southwest YPVF used Landsat 8 thermal infrared data estimate radiative heat flow. Most this region is close proximity Caldera boundary. Springs fumaroles...