Bill Evans, PhD (Former Employee)
Science and Products
Filter Total Items: 110
Geochemical investigation of the hydrothermal system on Akutan Island, Alaska, July 2012 Geochemical investigation of the hydrothermal system on Akutan Island, Alaska, July 2012
We have studied the geochemistry of the hot springs on Akutan Island in detail for the first time since the early 1980s. Springs in four discrete groups (A-D) along Hot Springs Creek showed generally higher temperatures and substantially higher Na, Ca, and Cl concentrations than previously reported, and total hot-spring discharge has also increased markedly. The springs now account for a...
Authors
D. Bergfeld, Jennifer L. Lewicki, William C. Evans, Andrew G. Hunt, Kinga Revesz, Mark Huebner
Ca, Sr, O and D isotope approach to defining the chemical evolution of hydrothermal fluids: example from Long Valley, CA, USA Ca, Sr, O and D isotope approach to defining the chemical evolution of hydrothermal fluids: example from Long Valley, CA, USA
We present chemical and isotopic data for fluids, minerals and rocks from the Long Valley meteoric-hydrothermal system. The samples encompass the presumed hydrothermal upwelling zone in the west moat of the caldera, the Casa Diablo geothermal field, and a series of wells defining a nearly linear, ∼16 km long, west-to-east trend along the likely fluid flow path. Fluid samples were...
Authors
Shaun T. Brown, B. Mack Kennedy, Donald J. DePaolo, Shaul Hurwitz, William C. Evans
Summit crater lake observations, and the location, chemistry, and pH of water samples near Mount Chiginagak volcano, Alaska: 2004-2012 Summit crater lake observations, and the location, chemistry, and pH of water samples near Mount Chiginagak volcano, Alaska: 2004-2012
Mount Chiginagak is a hydrothermally active volcano on the Alaska Peninsula, approximately 170 km south–southwest of King Salmon, Alaska (fig. 1). This small stratovolcano, approximately 8 km in diameter, has erupted through Tertiary to Permian sedimentary and igneous rocks (Detterman and others, 1987). The highest peak is at an elevation of 2,135 m, and the upper ~1,000 m of the volcano...
Authors
Janet R. Schaefer, William E. Scott, William C. Evans, Bronwen Wang, Robert G. McGimsey
Airborne filter pack measurements of S and Cl in the plume of Redoubt Volcano, Alaska February–May 2009 Airborne filter pack measurements of S and Cl in the plume of Redoubt Volcano, Alaska February–May 2009
Filter pack data from six airborne campaigns at Redoubt Volcano, Alaska are reported here. These measurements provide a rare constraint on Cl output from an andesitic eruption at high emission rate (> 104 t d− 1 SO2). Four S/Cl ratios measured during a period of lava dome growth indicate a depth of last magma equilibration of 2–5 km. The S/Cl ratios in combination with COSPEC SO2...
Authors
Melissa Pfeffer, Michael P. Doukas, Cynthia A. Werner, William C. Evans
Temporal variations of geyser water chemistry in the Upper Geyser Basin, Yellowstone National Park, USA Temporal variations of geyser water chemistry in the Upper Geyser Basin, Yellowstone National Park, USA
Geysers are rare features that reflect a delicate balance between an abundant supply of water and heat and a unique geometry of fractures and porous rocks. Between April 2007 and September 2008, we sampled Old Faithful, Daisy, Grand, Oblong, and Aurum geysers in Yellowstone National Park's Upper Geyser Basin and characterized temporal variations in major element chemistry and water...
Authors
Shaul Hurwitz, Andrew G. Hunt, William C. Evans
Insights from fumarole gas geochemistry on the origin of hydrothermal fluids on the Yellowstone Plateau Insights from fumarole gas geochemistry on the origin of hydrothermal fluids on the Yellowstone Plateau
The chemistry of Yellowstone fumarole gases shows the existence of two component waters, type MC, influenced by the addition of deep mantle fluid, and type CC, influenced by crustal interactions (CC). MC is high in 3He/4He (22 Ra) and low in 4He/40Ar (∼1), reflecting input of deep mantle components. The other water is characterized by 4He concentrations 3–4 orders of magnitude higher...
Authors
Giovanni Chiodini, Stefano Caliro, Jacob B. Lowenstern, William C. Evans, D. Bergfeld, Franco Tassi, Dario Tedesco
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
Filter Total Items: 110
Geochemical investigation of the hydrothermal system on Akutan Island, Alaska, July 2012 Geochemical investigation of the hydrothermal system on Akutan Island, Alaska, July 2012
We have studied the geochemistry of the hot springs on Akutan Island in detail for the first time since the early 1980s. Springs in four discrete groups (A-D) along Hot Springs Creek showed generally higher temperatures and substantially higher Na, Ca, and Cl concentrations than previously reported, and total hot-spring discharge has also increased markedly. The springs now account for a...
Authors
D. Bergfeld, Jennifer L. Lewicki, William C. Evans, Andrew G. Hunt, Kinga Revesz, Mark Huebner
Ca, Sr, O and D isotope approach to defining the chemical evolution of hydrothermal fluids: example from Long Valley, CA, USA Ca, Sr, O and D isotope approach to defining the chemical evolution of hydrothermal fluids: example from Long Valley, CA, USA
We present chemical and isotopic data for fluids, minerals and rocks from the Long Valley meteoric-hydrothermal system. The samples encompass the presumed hydrothermal upwelling zone in the west moat of the caldera, the Casa Diablo geothermal field, and a series of wells defining a nearly linear, ∼16 km long, west-to-east trend along the likely fluid flow path. Fluid samples were...
Authors
Shaun T. Brown, B. Mack Kennedy, Donald J. DePaolo, Shaul Hurwitz, William C. Evans
Summit crater lake observations, and the location, chemistry, and pH of water samples near Mount Chiginagak volcano, Alaska: 2004-2012 Summit crater lake observations, and the location, chemistry, and pH of water samples near Mount Chiginagak volcano, Alaska: 2004-2012
Mount Chiginagak is a hydrothermally active volcano on the Alaska Peninsula, approximately 170 km south–southwest of King Salmon, Alaska (fig. 1). This small stratovolcano, approximately 8 km in diameter, has erupted through Tertiary to Permian sedimentary and igneous rocks (Detterman and others, 1987). The highest peak is at an elevation of 2,135 m, and the upper ~1,000 m of the volcano...
Authors
Janet R. Schaefer, William E. Scott, William C. Evans, Bronwen Wang, Robert G. McGimsey
Airborne filter pack measurements of S and Cl in the plume of Redoubt Volcano, Alaska February–May 2009 Airborne filter pack measurements of S and Cl in the plume of Redoubt Volcano, Alaska February–May 2009
Filter pack data from six airborne campaigns at Redoubt Volcano, Alaska are reported here. These measurements provide a rare constraint on Cl output from an andesitic eruption at high emission rate (> 104 t d− 1 SO2). Four S/Cl ratios measured during a period of lava dome growth indicate a depth of last magma equilibration of 2–5 km. The S/Cl ratios in combination with COSPEC SO2...
Authors
Melissa Pfeffer, Michael P. Doukas, Cynthia A. Werner, William C. Evans
Temporal variations of geyser water chemistry in the Upper Geyser Basin, Yellowstone National Park, USA Temporal variations of geyser water chemistry in the Upper Geyser Basin, Yellowstone National Park, USA
Geysers are rare features that reflect a delicate balance between an abundant supply of water and heat and a unique geometry of fractures and porous rocks. Between April 2007 and September 2008, we sampled Old Faithful, Daisy, Grand, Oblong, and Aurum geysers in Yellowstone National Park's Upper Geyser Basin and characterized temporal variations in major element chemistry and water...
Authors
Shaul Hurwitz, Andrew G. Hunt, William C. Evans
Insights from fumarole gas geochemistry on the origin of hydrothermal fluids on the Yellowstone Plateau Insights from fumarole gas geochemistry on the origin of hydrothermal fluids on the Yellowstone Plateau
The chemistry of Yellowstone fumarole gases shows the existence of two component waters, type MC, influenced by the addition of deep mantle fluid, and type CC, influenced by crustal interactions (CC). MC is high in 3He/4He (22 Ra) and low in 4He/40Ar (∼1), reflecting input of deep mantle components. The other water is characterized by 4He concentrations 3–4 orders of magnitude higher...
Authors
Giovanni Chiodini, Stefano Caliro, Jacob B. Lowenstern, William C. Evans, D. Bergfeld, Franco Tassi, Dario Tedesco
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.