Andrew G Hunt
Andy Hunt is a Research Geologist with the Geology, Geophysics, and Geochemistry Science Center.
Science and Products
Filter Total Items: 60
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 heat outp
Authors
D. Bergfeld, Jennifer L. Lewicki, William C. Evans, Andrew G. Hunt, Kinga Revesz, Mark Huebner
Noble gas geochemistry investigation of high CO2 natural gas at the LaBarge Platform, Wyoming, USA
A regional sampling of gases from thermal springs near the LaBarge Field, Wyoming, USA to determine the extent of the total carbon dioxide system (TCDS) indicates that the system may extend up to 70 km to the northwest of the field. Geochemical evidence from noble gas isotopes, stable element isotopes, and gas composition provide the foundation for these conclusions. Samples from Soda Springs to t
Authors
Matthew D. Merrill, Andrew G. Hunt, Celeste D. Lohr
Evidence for high salinity of Early Cretaceous sea water from the Chesapeake Bay crater
High salinity groundwater more than 1000 metres deep in the Atlantic Coastal Plain of the United States has been documented in several locations1,2, most recently within the 35 million-year-old Chesapeake Bay impact crater3,4,5. Suggestions for the origin of increased salinity in the crater have included evaporite dissolution6, osmosis6, and evaporation from heating7 associated with the bolide imp
Authors
Ward E. Sanford, Michael W. Doughten, Tyler B. Coplen, Andrew G. Hunt, Thomas D. Bullen
Groundwater ages and mixing in the Piceance Basin natural gas province, Colorado
Reliably identifying the effects of energy development on groundwater quality can be difficult because baseline assessments of water quality completed before the onset of energy development are rare and because interactions between hydrocarbon reservoirs and aquifers can be complex, involving both natural and human processes. Groundwater age and mixing data can strengthen interpretations of monito
Authors
Peter B. McMahon, Judith C. Thomas, Andrew G. Hunt
Chemistry and age of groundwater in the Piceance structural basin, Rio Blanco county, Colorado, 2010-12
Fourteen monitoring wells were sampled by the U.S. Geological Survey, in cooperation with the Bureau of Land Management, to better understand the chemistry and age of groundwater in the Piceance structural basin in Rio Blanco County, Colorado, and how they may relate to the development of underlying natural-gas reservoirs. Natural gas extraction in the area has been ongoing since at least the 1950
Authors
Peter B. McMahon, Judith C. Thomas, Andrew G. Hunt
Tracing groundwater with low-level detections of halogenated VOCs in a fractured carbonate-rock aquifer, Leetown Science Center, West Virginia, USA
Measurements of low-level concentrations of halogenated volatile organic compounds (VOCs) and estimates of groundwater age interpreted from 3H/3He and SF6 data have led to an improved understanding of groundwater flow, water sources, and transit times in a karstic, fractured, carbonate-rock aquifer at the Leetown Science Center (LSC), West Virginia. The sum of the concentrations of a set of 16 pre
Authors
Niel Plummer, Philip L. Sibrell, Gerolamo C. Casile, Eurybiades Busenberg, Andrew G. Hunt, Peter Schlosser
Mass fractionation of noble gases in synthetic methane hydrate: Implications for naturally occurring gas hydrate dissociation
As a consequence of contemporary or longer term (since 15 ka) climate warming, gas hydrates in some settings may presently be dissociating and releasing methane and other gases to the ocean-atmosphere system. A key challenge in assessing the impact of dissociating gas hydrates on global atmospheric methane is the lack of a technique able to distinguish between methane recently released from gas hy
Authors
Andrew G. Hunt, Laura Stern, John W. Pohlman, Carolyn Ruppel, Richard J. Moscati, Gary P. Landis
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 isotopes (δ18O,
Authors
Shaul Hurwitz, Andrew G. Hunt, William C. Evans
Using geochemistry to identify the source of groundwater to Montezuma Well, a natural spring in Central Arizona, USA: Part 2
Montezuma Well is a unique natural spring located in a sinkhole surrounded by travertine. Montezuma Well is managed by the National Park Service, and groundwater development in the area is a potential threat to the water source for Montezuma Well. This research was undertaken to better understand the sources of groundwater to Montezuma Well. Strontium isotopes (87Sr/86Sr) indicate that groundwater
Authors
Raymond H. Johnson, Ed DeWitt, Laurie Wirt, Andrew H. Manning, Andrew G. Hunt
Determining the source and genetic fingerprint of natural gases using noble gas geochemistry: a northern Appalachian Basin case study
Silurian and Devonian natural gas reservoirs present within New York state represent an example of unconventional gas accumulations within the northern Appalachian Basin. These unconventional energy resources, previously thought to be noneconomically viable, have come into play following advances in drilling (i.e., horizontal drilling) and extraction (i.e., hydraulic fracturing) capabilities. Ther
Authors
Andrew G. Hunt, Thomas H. Darrah, Robert J. Poreda
Old groundwater in parts of the upper Patapsco aquifer, Atlantic Coastal Plain, Maryland, USA: Evidence from radiocarbon, chlorine-36 and helium-4
Apparent groundwater ages along two flow paths in the upper Patapsco aquifer of the Maryland Atlantic Coastal Plain, USA, were estimated using 14C, 36Cl and 4He data. Most of the ages range from modern to about 500 ka, with one sample at 117 km downgradient from the recharge area dated by radiogenic 4He accumulation at more than one Ma. Last glacial maximum (LGM) water was located about 20 km down
Authors
Niel Plummer, John R. Eggleston, Jeff P. Raffensperger, Andrew G. Hunt, Gerolamo C. Casile, D. C. Andreasen
Observations of mass fractionation of noble gases in synthetic methane hydrate
As a consequence of contemporary or longer term (since 15 ka) climate warming, gas hydrates in some settings are presently dissociating and releasing methane and other gases to the oceanatmosphere system. A key challenge in assessing the susceptibility of gas hydrates to warming climate is the lack of a technique able to distinguish between methane recently released from gas hydrates and methane e
Authors
Andrew G. Hunt, John W. Pohlman, Laura A. Stern, Carolyn D. Ruppel, Richard J. Moscati, Gary P. Landis, John C. Pinkston
Science and Products
Filter Total Items: 60
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 heat outp
Authors
D. Bergfeld, Jennifer L. Lewicki, William C. Evans, Andrew G. Hunt, Kinga Revesz, Mark Huebner
Noble gas geochemistry investigation of high CO2 natural gas at the LaBarge Platform, Wyoming, USA
A regional sampling of gases from thermal springs near the LaBarge Field, Wyoming, USA to determine the extent of the total carbon dioxide system (TCDS) indicates that the system may extend up to 70 km to the northwest of the field. Geochemical evidence from noble gas isotopes, stable element isotopes, and gas composition provide the foundation for these conclusions. Samples from Soda Springs to t
Authors
Matthew D. Merrill, Andrew G. Hunt, Celeste D. Lohr
Evidence for high salinity of Early Cretaceous sea water from the Chesapeake Bay crater
High salinity groundwater more than 1000 metres deep in the Atlantic Coastal Plain of the United States has been documented in several locations1,2, most recently within the 35 million-year-old Chesapeake Bay impact crater3,4,5. Suggestions for the origin of increased salinity in the crater have included evaporite dissolution6, osmosis6, and evaporation from heating7 associated with the bolide imp
Authors
Ward E. Sanford, Michael W. Doughten, Tyler B. Coplen, Andrew G. Hunt, Thomas D. Bullen
Groundwater ages and mixing in the Piceance Basin natural gas province, Colorado
Reliably identifying the effects of energy development on groundwater quality can be difficult because baseline assessments of water quality completed before the onset of energy development are rare and because interactions between hydrocarbon reservoirs and aquifers can be complex, involving both natural and human processes. Groundwater age and mixing data can strengthen interpretations of monito
Authors
Peter B. McMahon, Judith C. Thomas, Andrew G. Hunt
Chemistry and age of groundwater in the Piceance structural basin, Rio Blanco county, Colorado, 2010-12
Fourteen monitoring wells were sampled by the U.S. Geological Survey, in cooperation with the Bureau of Land Management, to better understand the chemistry and age of groundwater in the Piceance structural basin in Rio Blanco County, Colorado, and how they may relate to the development of underlying natural-gas reservoirs. Natural gas extraction in the area has been ongoing since at least the 1950
Authors
Peter B. McMahon, Judith C. Thomas, Andrew G. Hunt
Tracing groundwater with low-level detections of halogenated VOCs in a fractured carbonate-rock aquifer, Leetown Science Center, West Virginia, USA
Measurements of low-level concentrations of halogenated volatile organic compounds (VOCs) and estimates of groundwater age interpreted from 3H/3He and SF6 data have led to an improved understanding of groundwater flow, water sources, and transit times in a karstic, fractured, carbonate-rock aquifer at the Leetown Science Center (LSC), West Virginia. The sum of the concentrations of a set of 16 pre
Authors
Niel Plummer, Philip L. Sibrell, Gerolamo C. Casile, Eurybiades Busenberg, Andrew G. Hunt, Peter Schlosser
Mass fractionation of noble gases in synthetic methane hydrate: Implications for naturally occurring gas hydrate dissociation
As a consequence of contemporary or longer term (since 15 ka) climate warming, gas hydrates in some settings may presently be dissociating and releasing methane and other gases to the ocean-atmosphere system. A key challenge in assessing the impact of dissociating gas hydrates on global atmospheric methane is the lack of a technique able to distinguish between methane recently released from gas hy
Authors
Andrew G. Hunt, Laura Stern, John W. Pohlman, Carolyn Ruppel, Richard J. Moscati, Gary P. Landis
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 isotopes (δ18O,
Authors
Shaul Hurwitz, Andrew G. Hunt, William C. Evans
Using geochemistry to identify the source of groundwater to Montezuma Well, a natural spring in Central Arizona, USA: Part 2
Montezuma Well is a unique natural spring located in a sinkhole surrounded by travertine. Montezuma Well is managed by the National Park Service, and groundwater development in the area is a potential threat to the water source for Montezuma Well. This research was undertaken to better understand the sources of groundwater to Montezuma Well. Strontium isotopes (87Sr/86Sr) indicate that groundwater
Authors
Raymond H. Johnson, Ed DeWitt, Laurie Wirt, Andrew H. Manning, Andrew G. Hunt
Determining the source and genetic fingerprint of natural gases using noble gas geochemistry: a northern Appalachian Basin case study
Silurian and Devonian natural gas reservoirs present within New York state represent an example of unconventional gas accumulations within the northern Appalachian Basin. These unconventional energy resources, previously thought to be noneconomically viable, have come into play following advances in drilling (i.e., horizontal drilling) and extraction (i.e., hydraulic fracturing) capabilities. Ther
Authors
Andrew G. Hunt, Thomas H. Darrah, Robert J. Poreda
Old groundwater in parts of the upper Patapsco aquifer, Atlantic Coastal Plain, Maryland, USA: Evidence from radiocarbon, chlorine-36 and helium-4
Apparent groundwater ages along two flow paths in the upper Patapsco aquifer of the Maryland Atlantic Coastal Plain, USA, were estimated using 14C, 36Cl and 4He data. Most of the ages range from modern to about 500 ka, with one sample at 117 km downgradient from the recharge area dated by radiogenic 4He accumulation at more than one Ma. Last glacial maximum (LGM) water was located about 20 km down
Authors
Niel Plummer, John R. Eggleston, Jeff P. Raffensperger, Andrew G. Hunt, Gerolamo C. Casile, D. C. Andreasen
Observations of mass fractionation of noble gases in synthetic methane hydrate
As a consequence of contemporary or longer term (since 15 ka) climate warming, gas hydrates in some settings are presently dissociating and releasing methane and other gases to the oceanatmosphere system. A key challenge in assessing the susceptibility of gas hydrates to warming climate is the lack of a technique able to distinguish between methane recently released from gas hydrates and methane e
Authors
Andrew G. Hunt, John W. Pohlman, Laura A. Stern, Carolyn D. Ruppel, Richard J. Moscati, Gary P. Landis, John C. Pinkston