Margaret Mangan, PhD (Former Employee)
Science and Products
California volcano locations, threat rank and hazard zones California volcano locations, threat rank and hazard zones
The California volcano locations, threat rank and hazard zones data release contains two shapefiles for download or use as a web map service. The California Volcanic Center Locations shapefile was created to provide a generalized location of volcano hazard sources. The California Volcano Hazard Zones shapefile was created from previously published hazard zone reports. Specific details...
Filter Total Items: 28
Constraints on deep, CO2-rich degassing at arc volcanoes from solubility experiments on hydrous basaltic andesite of Pavlof Volcano, Alaska Peninsula, at 300 to 1200 MPa Constraints on deep, CO2-rich degassing at arc volcanoes from solubility experiments on hydrous basaltic andesite of Pavlof Volcano, Alaska Peninsula, at 300 to 1200 MPa
The solubility of CO2 in hydrous basaltic andesite was examined in fO2-controlled experiments at a temperature of 1125 °C and pressures between 310–1200 MPa. Concentrations of dissolved H2O and CO2 in experimental glasses were determined by ion microprobe calibrated on a subset of run glasses analyzed by high-temperature vacuum manometry. Assuming that the solubility of H2O in mafic melt...
Authors
Margaret Mangan, Thomas W. Sisson, W. Ben Hankins, Nobumichi Shimizu, Torsten W. Vennemann
Geophysical characterization of the Northwest Geysers geothermal field, California Geophysical characterization of the Northwest Geysers geothermal field, California
The Clear Lake Volcanic Field in northern California is the youngest and northern-most part of a long-lived volcanic system that has produced recent (~10 ka) eruptions. Adjacent to the Clear Lake Volcanic Field is the worlds largest energy producing geothermal field, The Geysers. The hottest part of The Geysers geothermal field is in the northwest where temperatures reach ~400 C at 3 km...
Authors
Jared R. Peacock, Tait E. Earney, Margret T. Mangan, William D. Schermerhorn, Jonathan M.G. Glen, Mark Walters, Craig Hartline
Rate of magma supply beneath Mammoth Mountain, California based on helium isotopes and CO2 emissions Rate of magma supply beneath Mammoth Mountain, California based on helium isotopes and CO2 emissions
Mammoth Mountain, California, has exhibited unrest over the past ~30 years, characterized by seismicity over a broad range of depths, elevated 3He/4He ratios in fumarolic gas, and large-scale diffuse CO2 emissions. This activity has been attributed to magmatic intrusion, but minimal ground deformation and the presence of a shallow crustal gas reservoir beneath Mammoth Mountain pose a...
Authors
Jennifer L. Lewicki, William C. Evans, Emily K. Montgomery-Brown, Margaret T. Mangan, John King, Andrew G. Hunt
California’s exposure to volcanic hazards California’s exposure to volcanic hazards
The potential for damaging earthquakes, landslides, floods, tsunamis, and wildfires is widely recognized in California. The same cannot be said for volcanic eruptions, despite the fact that they occur in the state about as frequently as the largest earthquakes on the San Andreas Fault. At least ten eruptions have taken place in the past 1,000 years, and future volcanic eruptions are...
Authors
Margaret Mangan, Jessica Ball, Nathan Wood, Jamie L. Jones, Jeff Peters, Nina Abdollahian, Laura Dinitz, Sharon Blankenheim, Johanna Fenton, Cynthia Pridmore
By
Volcano Hazards Program, Volcano Science Center, California Volcano Observatory, Clear Lake Volcanic Field, Coso Volcanic Field, Lassen Volcanic Center, Long Valley Caldera, Mammoth Mountain, Medicine Lake, Mono Lake Volcanic Field, Mono-Inyo Craters, Mount Shasta, Salton Buttes, Soda Lakes, Ubehebe Craters
Geophysical Characterization of the heat source in the Northwest Geysers, California Geophysical Characterization of the heat source in the Northwest Geysers, California
The Geysers, in northern California, is the largest energy producing geothermal field in the world. Looking to expand capacity, the operator Calpine Corporation developed an anomalously hot (~400 °C at 2.5 km depth) part of the field in the northwest Geysers, including testing of an enhanced geothermal systems (EGS). Though the area is anomalously hot, geophysical methods have failed to...
Authors
Jared R. Peacock, Margaret T. Mangan, Mark Walters, Craig Hartline, Jonathan M.G. Glen, Tait E. Earney, William D. Schermerhorn
United States-Chile binational exchange for volcanic risk reduction, 2015—Activities and benefits United States-Chile binational exchange for volcanic risk reduction, 2015—Activities and benefits
In 2015, representatives from the United States and Chile exchanged visits to discuss and share their expertise and experiences dealing with volcano hazards. Communities in both countries are at risk from various volcano hazards. Risks to lives and property posed by these hazards are a function not only of the type and size of future eruptions but also of distances from volcanoes...
Authors
Thomas C. Pierson, Margaret T. Mangan, Luis E. Lara Pulgar, Alvaro Ramos Amigo
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
California volcano locations, threat rank and hazard zones California volcano locations, threat rank and hazard zones
The California volcano locations, threat rank and hazard zones data release contains two shapefiles for download or use as a web map service. The California Volcanic Center Locations shapefile was created to provide a generalized location of volcano hazard sources. The California Volcano Hazard Zones shapefile was created from previously published hazard zone reports. Specific details...
Filter Total Items: 28
Constraints on deep, CO2-rich degassing at arc volcanoes from solubility experiments on hydrous basaltic andesite of Pavlof Volcano, Alaska Peninsula, at 300 to 1200 MPa Constraints on deep, CO2-rich degassing at arc volcanoes from solubility experiments on hydrous basaltic andesite of Pavlof Volcano, Alaska Peninsula, at 300 to 1200 MPa
The solubility of CO2 in hydrous basaltic andesite was examined in fO2-controlled experiments at a temperature of 1125 °C and pressures between 310–1200 MPa. Concentrations of dissolved H2O and CO2 in experimental glasses were determined by ion microprobe calibrated on a subset of run glasses analyzed by high-temperature vacuum manometry. Assuming that the solubility of H2O in mafic melt...
Authors
Margaret Mangan, Thomas W. Sisson, W. Ben Hankins, Nobumichi Shimizu, Torsten W. Vennemann
Geophysical characterization of the Northwest Geysers geothermal field, California Geophysical characterization of the Northwest Geysers geothermal field, California
The Clear Lake Volcanic Field in northern California is the youngest and northern-most part of a long-lived volcanic system that has produced recent (~10 ka) eruptions. Adjacent to the Clear Lake Volcanic Field is the worlds largest energy producing geothermal field, The Geysers. The hottest part of The Geysers geothermal field is in the northwest where temperatures reach ~400 C at 3 km...
Authors
Jared R. Peacock, Tait E. Earney, Margret T. Mangan, William D. Schermerhorn, Jonathan M.G. Glen, Mark Walters, Craig Hartline
Rate of magma supply beneath Mammoth Mountain, California based on helium isotopes and CO2 emissions Rate of magma supply beneath Mammoth Mountain, California based on helium isotopes and CO2 emissions
Mammoth Mountain, California, has exhibited unrest over the past ~30 years, characterized by seismicity over a broad range of depths, elevated 3He/4He ratios in fumarolic gas, and large-scale diffuse CO2 emissions. This activity has been attributed to magmatic intrusion, but minimal ground deformation and the presence of a shallow crustal gas reservoir beneath Mammoth Mountain pose a...
Authors
Jennifer L. Lewicki, William C. Evans, Emily K. Montgomery-Brown, Margaret T. Mangan, John King, Andrew G. Hunt
California’s exposure to volcanic hazards California’s exposure to volcanic hazards
The potential for damaging earthquakes, landslides, floods, tsunamis, and wildfires is widely recognized in California. The same cannot be said for volcanic eruptions, despite the fact that they occur in the state about as frequently as the largest earthquakes on the San Andreas Fault. At least ten eruptions have taken place in the past 1,000 years, and future volcanic eruptions are...
Authors
Margaret Mangan, Jessica Ball, Nathan Wood, Jamie L. Jones, Jeff Peters, Nina Abdollahian, Laura Dinitz, Sharon Blankenheim, Johanna Fenton, Cynthia Pridmore
By
Volcano Hazards Program, Volcano Science Center, California Volcano Observatory, Clear Lake Volcanic Field, Coso Volcanic Field, Lassen Volcanic Center, Long Valley Caldera, Mammoth Mountain, Medicine Lake, Mono Lake Volcanic Field, Mono-Inyo Craters, Mount Shasta, Salton Buttes, Soda Lakes, Ubehebe Craters
Geophysical Characterization of the heat source in the Northwest Geysers, California Geophysical Characterization of the heat source in the Northwest Geysers, California
The Geysers, in northern California, is the largest energy producing geothermal field in the world. Looking to expand capacity, the operator Calpine Corporation developed an anomalously hot (~400 °C at 2.5 km depth) part of the field in the northwest Geysers, including testing of an enhanced geothermal systems (EGS). Though the area is anomalously hot, geophysical methods have failed to...
Authors
Jared R. Peacock, Margaret T. Mangan, Mark Walters, Craig Hartline, Jonathan M.G. Glen, Tait E. Earney, William D. Schermerhorn
United States-Chile binational exchange for volcanic risk reduction, 2015—Activities and benefits United States-Chile binational exchange for volcanic risk reduction, 2015—Activities and benefits
In 2015, representatives from the United States and Chile exchanged visits to discuss and share their expertise and experiences dealing with volcano hazards. Communities in both countries are at risk from various volcano hazards. Risks to lives and property posed by these hazards are a function not only of the type and size of future eruptions but also of distances from volcanoes...
Authors
Thomas C. Pierson, Margaret T. Mangan, Luis E. Lara Pulgar, Alvaro Ramos Amigo
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.