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: 52
Petrogenesis of Mount Rainier andesite: Magma flux and geologic controls on the contrasting differentiation styles at stratovolcanoes of the southern Washington Cascades
Quaternary Mount Rainier (Washington, USA) of the Cascades magmatic arc consists of porphyritic calc-alkaline andesites and subordinate dacites, with common evidence for mingling and mixing with less evolved magmas encompassing andesites, basaltic andesites, and rarely, basalts. Basaltic andesites and amphibole andesites (spessartites) that erupted from vents at the north foot of the volcano repre
Authors
Thomas W. Sisson, V. J. M. Salters, P.B. Larson
Geologic map of southwestern Sequoia National Park, Tulare County, California
This map shows the geology of 675 km2 (260 mi2) on the west slope of the Sierra Nevada, California, mainly in Sequoia National Park and Sequoia National Forest. It was produced by the U.S. Geological Survey (USGS) at the request of the National Park Service to complete the geologic map coverage of Kings Canyon and Sequoia National Parks. The area includes the Mineral King 15’ topographic quadrangl
Authors
Thomas W. Sisson, James G. Moore
Andesites of the 2009 eruption of Redoubt Volcano, Alaska
Crystal-rich andesites that erupted from Redoubt Volcano in 2009 range from 57.5 to 62.5 wt.% SiO2 and have phenocryst and phenocryst-melt relations consistent with staging in the upper crust. Early explosive products are low-silica andesites (LSA, < 58 wt.% SiO2) that ascended from deeper crustal levels during or before the 6 months of precursory activity, but a broad subsequent succession to mor
Authors
Michelle L. Coombs, Thomas W. Sisson, Heather A. Bleick, Sarah M. Henton, Christopher J. Nye, Allison Payne, Cheryl E. Cameron, Jessica F. Larsen, Kristi L. Wallace, Katharine F. Bull
Sixty thousand years of magmatic volatile history before the caldera-forming eruption of Mount Mazama, Crater Lake, Oregon
The well-documented eruptive history of Mount Mazama, Oregon, provides an excellent opportunity to use pre-eruptive volatile concentrations to study the growth of an explosive silicic magmatic system. Melt inclusions (MI) hosted in pyroxene and plagioclase crystals from eight dacitic–rhyodacitic eruptive deposits (71–7.7 ka) were analyzed to determine variations in volatile-element concentrations
Authors
Heather M. Wright, Charles R. Bacon, Jorge A. Vazquez, Thomas W. Sisson
Segregating gas from melt: an experimental study of the Ostwald ripening of vapor bubbles in magmas
Diffusive coarsening (Ostwald ripening) of H2O and H2O-CO2 bubbles in rhyolite and basaltic andesite melts was studied with elevated temperature–pressure experiments to investigate the rates and time spans over which vapor bubbles may enlarge and attain sufficient buoyancy to segregate in magmatic systems. Bubble growth and segregation are also considered in terms of classical steady-state and tra
Authors
Nicole C. Lautze, Thomas W. Sisson, Margaret T. Mangan, Timothy L. Grove
Digital topographic map showing the extents of glacial ice and perennial snowfields at Mount Rainier, Washington, based on the LiDAR survey of September 2007 to October 2008
In response to severe flooding in November 2006, the National Park Service contracted for a high-resolution aerial Light Detection and Ranging (LiDAR) topographic survey of Mount Rainier National Park, Washington. Due to inclement weather, this survey was performed in two stages: early September 2007 and September-October 2008. The total surveyed area of 241,585 acres includes an approximately 100
Authors
Joel E. Robinson, Thomas W. Sisson, Darin D. Swinney
Source materials for inception stage Hawaiian magmas: Pb‐He isotope variations for early Kilauea
New noble gas and radiogenic isotopic compositions are presented for tholeiitic, transitional, and alkalic rocks from the submarine Hilina region on the south flank of Kilauea, Hawaii. The 3He/4He ratios for undegassed glass and olivine separates (11–26 Ra) contrast with those of postshield and rejuvenated alkalic lavas, consistent with the alkalic and transitional basalts at Hilina corresponding
Authors
Takeshi Hanyu, Jun-Ichi Kimura, Maiko Katakuse, Andrew T. Calvert, Thomas W. Sisson, Shun'ichi Nakai
Volcano monitoring
Volcanoes are not randomly distributed over the Earth's surface. Most are concentrated on the edges of continents, along island chains, or beneath the sea where they form long mountain ranges. More than half of the world's active volcanoes above sea level encircle the Pacific Ocean (see Fig. 1). The concept of plate tectonics explains the locations of volcanoes and their relationship to other larg
Authors
James G. Smith, Jonathan Dehn, Richard P. Hoblitt, Richard G. Lahusen, Jacob B. Lowenstern, Seth C. Moran, Lindsay McClelland, Kenneth A. McGee, Manuel Nathenson, Paul G. Okubo, John S. Pallister, Michael P. Poland, John A. Power, David J. Schneider, Thomas W. Sisson
Assessing the state of our knowledge of continental arc volcanism: The Tatara-San Pedro Complex, 36°S, Andean Southern Volcanic Zone: Talca and Tatara-San Pedro, Chile 4-12 February 2007
Tatara-San Pedro Volcanic Complex in Chile is one of the best studied continental arc volcanic centers in the world. In connection to this, a field forum was conducted to discuss the processes involved in the construction of such volcanoes and the origins of its magmas. With 40 international participants from diverse scientific backgrounds, the forum opened in the Talca municipal library with two
Authors
Claude Jaupart, Thomas W. Sisson, Jon Blundy, Richard Arculus
Growth history of Kilauea inferred from volatile concentrations in submarine-collected basalts
Major-element and volatile (H2O, CO2, S) compositions of glasses from the submarine flanks of Kilauea Volcano record its growth from pre-shield into tholeiite shield-stage. Pillow lavas of mildly alkalic basalt at 2600–1900 mbsl on the upper slope of the south flank are an intermediate link between deeper alkalic volcaniclastics and the modern tholeiite shield. Lava clast glasses from the west fla
Authors
Michelle L. Coombs, Thomas W. Sisson, Peter W. Lipman
Isotope geochemistry of early Kilauea magmas from the submarine Hilina bench: The nature of the Hilina mantle component
Submarine lavas recovered from the Hilina bench region, offshore Kilauea, Hawaii Island provide information on ancient Kilauea volcano and the geochemical components of the Hawaiian hotspot. Alkalic lavas, including nephelinite, basanite, hawaiite, and alkali basalt, dominate the earliest stage of Kilauea magmatism. Transitional basalt pillow lavas are an intermediate phase, preceding development
Authors
Jun-Ichi Kimura, Thomas W. Sisson, Natsuko Nakano, Michelle L. Coombs, Peter W. Lipman
Piggyback tectonics: Long-term growth of Kilauea on the south flank of Mauna Loa
Compositional and age data from offshore pillow lavas and volcaniclastic sediments, along with on-land geologic, seismic, and deformation data, provide broad perspectives on the early growth of Kilauea Volcano and the long-term geometric evolution of its rift zones. Sulfur-rich glass rinds on pillow lavas and volcaniclastic sediments derived from them document early underwater growth of a large co
Authors
Peter W. Lipman, Thomas W. Sisson, Michelle L. Coombs, Andrew T. Calvert, Jun-Ichi Kimura
Science and Products
Filter Total Items: 52
Petrogenesis of Mount Rainier andesite: Magma flux and geologic controls on the contrasting differentiation styles at stratovolcanoes of the southern Washington Cascades
Quaternary Mount Rainier (Washington, USA) of the Cascades magmatic arc consists of porphyritic calc-alkaline andesites and subordinate dacites, with common evidence for mingling and mixing with less evolved magmas encompassing andesites, basaltic andesites, and rarely, basalts. Basaltic andesites and amphibole andesites (spessartites) that erupted from vents at the north foot of the volcano repre
Authors
Thomas W. Sisson, V. J. M. Salters, P.B. Larson
Geologic map of southwestern Sequoia National Park, Tulare County, California
This map shows the geology of 675 km2 (260 mi2) on the west slope of the Sierra Nevada, California, mainly in Sequoia National Park and Sequoia National Forest. It was produced by the U.S. Geological Survey (USGS) at the request of the National Park Service to complete the geologic map coverage of Kings Canyon and Sequoia National Parks. The area includes the Mineral King 15’ topographic quadrangl
Authors
Thomas W. Sisson, James G. Moore
Andesites of the 2009 eruption of Redoubt Volcano, Alaska
Crystal-rich andesites that erupted from Redoubt Volcano in 2009 range from 57.5 to 62.5 wt.% SiO2 and have phenocryst and phenocryst-melt relations consistent with staging in the upper crust. Early explosive products are low-silica andesites (LSA, < 58 wt.% SiO2) that ascended from deeper crustal levels during or before the 6 months of precursory activity, but a broad subsequent succession to mor
Authors
Michelle L. Coombs, Thomas W. Sisson, Heather A. Bleick, Sarah M. Henton, Christopher J. Nye, Allison Payne, Cheryl E. Cameron, Jessica F. Larsen, Kristi L. Wallace, Katharine F. Bull
Sixty thousand years of magmatic volatile history before the caldera-forming eruption of Mount Mazama, Crater Lake, Oregon
The well-documented eruptive history of Mount Mazama, Oregon, provides an excellent opportunity to use pre-eruptive volatile concentrations to study the growth of an explosive silicic magmatic system. Melt inclusions (MI) hosted in pyroxene and plagioclase crystals from eight dacitic–rhyodacitic eruptive deposits (71–7.7 ka) were analyzed to determine variations in volatile-element concentrations
Authors
Heather M. Wright, Charles R. Bacon, Jorge A. Vazquez, Thomas W. Sisson
Segregating gas from melt: an experimental study of the Ostwald ripening of vapor bubbles in magmas
Diffusive coarsening (Ostwald ripening) of H2O and H2O-CO2 bubbles in rhyolite and basaltic andesite melts was studied with elevated temperature–pressure experiments to investigate the rates and time spans over which vapor bubbles may enlarge and attain sufficient buoyancy to segregate in magmatic systems. Bubble growth and segregation are also considered in terms of classical steady-state and tra
Authors
Nicole C. Lautze, Thomas W. Sisson, Margaret T. Mangan, Timothy L. Grove
Digital topographic map showing the extents of glacial ice and perennial snowfields at Mount Rainier, Washington, based on the LiDAR survey of September 2007 to October 2008
In response to severe flooding in November 2006, the National Park Service contracted for a high-resolution aerial Light Detection and Ranging (LiDAR) topographic survey of Mount Rainier National Park, Washington. Due to inclement weather, this survey was performed in two stages: early September 2007 and September-October 2008. The total surveyed area of 241,585 acres includes an approximately 100
Authors
Joel E. Robinson, Thomas W. Sisson, Darin D. Swinney
Source materials for inception stage Hawaiian magmas: Pb‐He isotope variations for early Kilauea
New noble gas and radiogenic isotopic compositions are presented for tholeiitic, transitional, and alkalic rocks from the submarine Hilina region on the south flank of Kilauea, Hawaii. The 3He/4He ratios for undegassed glass and olivine separates (11–26 Ra) contrast with those of postshield and rejuvenated alkalic lavas, consistent with the alkalic and transitional basalts at Hilina corresponding
Authors
Takeshi Hanyu, Jun-Ichi Kimura, Maiko Katakuse, Andrew T. Calvert, Thomas W. Sisson, Shun'ichi Nakai
Volcano monitoring
Volcanoes are not randomly distributed over the Earth's surface. Most are concentrated on the edges of continents, along island chains, or beneath the sea where they form long mountain ranges. More than half of the world's active volcanoes above sea level encircle the Pacific Ocean (see Fig. 1). The concept of plate tectonics explains the locations of volcanoes and their relationship to other larg
Authors
James G. Smith, Jonathan Dehn, Richard P. Hoblitt, Richard G. Lahusen, Jacob B. Lowenstern, Seth C. Moran, Lindsay McClelland, Kenneth A. McGee, Manuel Nathenson, Paul G. Okubo, John S. Pallister, Michael P. Poland, John A. Power, David J. Schneider, Thomas W. Sisson
Assessing the state of our knowledge of continental arc volcanism: The Tatara-San Pedro Complex, 36°S, Andean Southern Volcanic Zone: Talca and Tatara-San Pedro, Chile 4-12 February 2007
Tatara-San Pedro Volcanic Complex in Chile is one of the best studied continental arc volcanic centers in the world. In connection to this, a field forum was conducted to discuss the processes involved in the construction of such volcanoes and the origins of its magmas. With 40 international participants from diverse scientific backgrounds, the forum opened in the Talca municipal library with two
Authors
Claude Jaupart, Thomas W. Sisson, Jon Blundy, Richard Arculus
Growth history of Kilauea inferred from volatile concentrations in submarine-collected basalts
Major-element and volatile (H2O, CO2, S) compositions of glasses from the submarine flanks of Kilauea Volcano record its growth from pre-shield into tholeiite shield-stage. Pillow lavas of mildly alkalic basalt at 2600–1900 mbsl on the upper slope of the south flank are an intermediate link between deeper alkalic volcaniclastics and the modern tholeiite shield. Lava clast glasses from the west fla
Authors
Michelle L. Coombs, Thomas W. Sisson, Peter W. Lipman
Isotope geochemistry of early Kilauea magmas from the submarine Hilina bench: The nature of the Hilina mantle component
Submarine lavas recovered from the Hilina bench region, offshore Kilauea, Hawaii Island provide information on ancient Kilauea volcano and the geochemical components of the Hawaiian hotspot. Alkalic lavas, including nephelinite, basanite, hawaiite, and alkali basalt, dominate the earliest stage of Kilauea magmatism. Transitional basalt pillow lavas are an intermediate phase, preceding development
Authors
Jun-Ichi Kimura, Thomas W. Sisson, Natsuko Nakano, Michelle L. Coombs, Peter W. Lipman
Piggyback tectonics: Long-term growth of Kilauea on the south flank of Mauna Loa
Compositional and age data from offshore pillow lavas and volcaniclastic sediments, along with on-land geologic, seismic, and deformation data, provide broad perspectives on the early growth of Kilauea Volcano and the long-term geometric evolution of its rift zones. Sulfur-rich glass rinds on pillow lavas and volcaniclastic sediments derived from them document early underwater growth of a large co
Authors
Peter W. Lipman, Thomas W. Sisson, Michelle L. Coombs, Andrew T. Calvert, Jun-Ichi Kimura