Thomas Winslow Sisson, PhD
I am a research geologist with the USGS Volcano Science Center. I have spent many years working on the geologic history and volcano hazards of Mount Rainier. My research interests include experimental petrology and volatile solubility of magmas.
Education and Certifications
Ph.D. Massachusetts Institute of Technology
M.S. UC Santa Barbara
B.S. Stanford University
Science and Products
Filter Total Items: 53
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 Sisson, W. Ben Hankins, Nobumichi Shimizu, Torsten Vennemann
Felsic melt and gas mobilisation during magma solidification: An experimental study at 1.1 kbar Felsic melt and gas mobilisation during magma solidification: An experimental study at 1.1 kbar
Melt and gas transfer processes are essential to the formation and growth of the Earth’s crust and for sustaining volcanic activity. These processes also play a major role in magma fractionation at shallow depths (
Authors
Mattia Pistone, Lukas Baumgartner, Florence Begue, Paul A. Jarvis, Elias Bloch, Martin Robyr, Othmar Muntener, Thomas Sisson, Jon Blundy
Age of the dacite of Sunset Amphitheater, a voluminous Pleistocene tephra from Mount Rainier (USA), and implications for Cascade glacial stratigraphy Age of the dacite of Sunset Amphitheater, a voluminous Pleistocene tephra from Mount Rainier (USA), and implications for Cascade glacial stratigraphy
The dacite of Sunset Amphitheater, Mount Rainier (USA), illustrates the difficulties in establishing accurate ages of Pleistocene tephra eruptions. Nearly uniform whole-rock, glass, and mineral compositions, texture, and phenocryst assemblage establish that certain conspicuous dissected pumice exposures scattered from Mount Rainier to southern Puget Sound are products of the same...
Authors
Thomas Sisson, Axel Schmitt, Martin Danisik, Andrew Calvert, Napoleon Pempena, Chun-Yuan Huang, Chuan-Chou Shen
Near-solidus melts of MORB + 4 wt% H2O at 0.8 – 2.8 GPa applied to issues of subduction magmatism and continent formation Near-solidus melts of MORB + 4 wt% H2O at 0.8 – 2.8 GPa applied to issues of subduction magmatism and continent formation
Experiments on MORB + 4 wt% H2O at 0.8–2.8 GPa and 700–950 °C (Liu in High pressure phase equilibria involving the amphibolite–eclogite transformation. PhD dissertation, Stanford University, Stanford, California, 1997; Liu et al. in Earth Planet Sci Lett 143:161–171, 1996) were reexamined for their major and trace element melt compositions and melting relations. Degree of melting...
Authors
Thomas Sisson, Peter Kelemen
Timescales of magmatic differentiation from alkali basalt to trachyte within the Harrat Rahat volcanic field, Kingdom of Saudi Arabia Timescales of magmatic differentiation from alkali basalt to trachyte within the Harrat Rahat volcanic field, Kingdom of Saudi Arabia
A fundamental goal of igneous petrology is to quantify the duration of time required to produce evolved magmas following influx of basalt into the crust. However, in many cases, complex field relations and/or the presence of a long-lived magmatic system make it difficult to assess how basaltic inputs relate to more evolved magmas, therefore, precluding calculation of meaningful...
Authors
Mark Stelten, Drew Downs, Hannah Dietterich, Gail Mahood, Andrew Calvert, Thomas Sisson, Hani Zahran, Jamal Shawali
Probing magma reservoirs to improve volcano forecasts Probing magma reservoirs to improve volcano forecasts
When it comes to forecasting eruptions, volcano observatories rely mostly on real-time signals from earthquakes, ground deformation, and gas discharge, combined with probabilistic assessments based on past behavior [Sparks and Cashman, 2017]. There is comparatively less reliance on geophysical and petrological understanding of subsurface magma reservoirs.
Authors
Jacob Lowenstern, Thomas Sisson, Shaul Hurwitz
Science and Products
Filter Total Items: 53
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 Sisson, W. Ben Hankins, Nobumichi Shimizu, Torsten Vennemann
Felsic melt and gas mobilisation during magma solidification: An experimental study at 1.1 kbar Felsic melt and gas mobilisation during magma solidification: An experimental study at 1.1 kbar
Melt and gas transfer processes are essential to the formation and growth of the Earth’s crust and for sustaining volcanic activity. These processes also play a major role in magma fractionation at shallow depths (
Authors
Mattia Pistone, Lukas Baumgartner, Florence Begue, Paul A. Jarvis, Elias Bloch, Martin Robyr, Othmar Muntener, Thomas Sisson, Jon Blundy
Age of the dacite of Sunset Amphitheater, a voluminous Pleistocene tephra from Mount Rainier (USA), and implications for Cascade glacial stratigraphy Age of the dacite of Sunset Amphitheater, a voluminous Pleistocene tephra from Mount Rainier (USA), and implications for Cascade glacial stratigraphy
The dacite of Sunset Amphitheater, Mount Rainier (USA), illustrates the difficulties in establishing accurate ages of Pleistocene tephra eruptions. Nearly uniform whole-rock, glass, and mineral compositions, texture, and phenocryst assemblage establish that certain conspicuous dissected pumice exposures scattered from Mount Rainier to southern Puget Sound are products of the same...
Authors
Thomas Sisson, Axel Schmitt, Martin Danisik, Andrew Calvert, Napoleon Pempena, Chun-Yuan Huang, Chuan-Chou Shen
Near-solidus melts of MORB + 4 wt% H2O at 0.8 – 2.8 GPa applied to issues of subduction magmatism and continent formation Near-solidus melts of MORB + 4 wt% H2O at 0.8 – 2.8 GPa applied to issues of subduction magmatism and continent formation
Experiments on MORB + 4 wt% H2O at 0.8–2.8 GPa and 700–950 °C (Liu in High pressure phase equilibria involving the amphibolite–eclogite transformation. PhD dissertation, Stanford University, Stanford, California, 1997; Liu et al. in Earth Planet Sci Lett 143:161–171, 1996) were reexamined for their major and trace element melt compositions and melting relations. Degree of melting...
Authors
Thomas Sisson, Peter Kelemen
Timescales of magmatic differentiation from alkali basalt to trachyte within the Harrat Rahat volcanic field, Kingdom of Saudi Arabia Timescales of magmatic differentiation from alkali basalt to trachyte within the Harrat Rahat volcanic field, Kingdom of Saudi Arabia
A fundamental goal of igneous petrology is to quantify the duration of time required to produce evolved magmas following influx of basalt into the crust. However, in many cases, complex field relations and/or the presence of a long-lived magmatic system make it difficult to assess how basaltic inputs relate to more evolved magmas, therefore, precluding calculation of meaningful...
Authors
Mark Stelten, Drew Downs, Hannah Dietterich, Gail Mahood, Andrew Calvert, Thomas Sisson, Hani Zahran, Jamal Shawali
Probing magma reservoirs to improve volcano forecasts Probing magma reservoirs to improve volcano forecasts
When it comes to forecasting eruptions, volcano observatories rely mostly on real-time signals from earthquakes, ground deformation, and gas discharge, combined with probabilistic assessments based on past behavior [Sparks and Cashman, 2017]. There is comparatively less reliance on geophysical and petrological understanding of subsurface magma reservoirs.
Authors
Jacob Lowenstern, Thomas Sisson, Shaul Hurwitz