Bill Evans, PhD
My research focused on volcanic volatiles and water-rock interaction in geothermal systems.
Gases are an important factor in volcanic hazards because of their role in driving explosive eruptions and their intrinsic toxicity. Part of the answer to, “What could happen?” at a restless volcano comes from gas studies. The mechanism of gas generation at depth and gas migration up through boiling hydrothermal systems, cold groundwaters, and the unsaturated zone are all complex processes that are only partly understood. The goal of my research is to use gas flux, composition, and isotope values to refine our general understanding of these processes and to apply this information to studies that focus on the behavior and hazards of individual volcanoes. The research involved identifying the areas of highest interest, planning the field investigations, determining the most appropriate sampling protocol, analyzing for the bulk composition and isotopic characteristics of the gas, and interpreting and publishing the results.
Science and Products
Summit crater lake observations, and the location, chemistry, and pH of water samples near Mount Chiginagak volcano, Alaska: 2004-2012
Airborne filter pack measurements of S and Cl in the plume of Redoubt Volcano, Alaska February–May 2009
Temporal variations of geyser water chemistry in the Upper Geyser Basin, Yellowstone National Park, USA
Insights from fumarole gas geochemistry on the origin of hydrothermal fluids on the Yellowstone Plateau
Solute and geothermal flux monitoring using electrical conductivity in the Madison, Firehole, and Gibbon Rivers, Yellowstone National Park
Avian mortality associated with a volcanic gas seep at Kiska Island, Aleutian Islands, Alaska
Deep magmatic degassing versus scrubbing: Elevated CO2 emissions and C/S in the lead-up to the 2009 eruption of Redoubt Volcano, Alaska
Water chemistry and electrical conductivity database for rivers in Yellowstone National Park, Wyoming
Monitoring CO2 emissions in tree kill areas near the resurgent dome at Long Valley Caldera, California
Carbon isotope composition of CO2 at Cascade Arc volcanoes
12th international symposium on water–rock interaction
Long-term changes in quiescent degassing at Mount Baker Volcano, Washington, USA; Evidence for a stalled intrusion in 1975 and connection to a deep magma source
Non-USGS Publications**
**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.
Science and Products
Summit crater lake observations, and the location, chemistry, and pH of water samples near Mount Chiginagak volcano, Alaska: 2004-2012
Airborne filter pack measurements of S and Cl in the plume of Redoubt Volcano, Alaska February–May 2009
Temporal variations of geyser water chemistry in the Upper Geyser Basin, Yellowstone National Park, USA
Insights from fumarole gas geochemistry on the origin of hydrothermal fluids on the Yellowstone Plateau
Solute and geothermal flux monitoring using electrical conductivity in the Madison, Firehole, and Gibbon Rivers, Yellowstone National Park
Avian mortality associated with a volcanic gas seep at Kiska Island, Aleutian Islands, Alaska
Deep magmatic degassing versus scrubbing: Elevated CO2 emissions and C/S in the lead-up to the 2009 eruption of Redoubt Volcano, Alaska
Water chemistry and electrical conductivity database for rivers in Yellowstone National Park, Wyoming
Monitoring CO2 emissions in tree kill areas near the resurgent dome at Long Valley Caldera, California
Carbon isotope composition of CO2 at Cascade Arc volcanoes
12th international symposium on water–rock interaction
Long-term changes in quiescent degassing at Mount Baker Volcano, Washington, USA; Evidence for a stalled intrusion in 1975 and connection to a deep magma source
Non-USGS Publications**
**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.