Publications
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Pre-1980 tephra-fall deposits erupted from Mount St. Helens, Washington Pre-1980 tephra-fall deposits erupted from Mount St. Helens, Washington
More than 100 tephra-fall deposits erupted from Mount St. Helens within about the last 40,000 years are grouped into tephra sets and layers distinguished from each other chiefly by differences in mineral composition and age. The tephra deposits record a complex history of the volcano, form important time-stratigraphic markers, and provide information about probable kinds, frequencies...
Authors
Donal R. Mullineaux
Long-period volcano seismicity: Its source and use in eruption forecasting Long-period volcano seismicity: Its source and use in eruption forecasting
At an active volcano, long-period seismicity (with typical periods in the range 0.2–2 s) reflects pressure fluctuations resulting from unsteady mass transport in the sub-surface plumbing system, and hence provides a glimpse of the internal dynamics of the volcanic edifice. When this activity occurs at shallow depths, it may signal the pressure-induced disruption of the steam-dominated...
Authors
Bernard A. Chouet
Intermediate‐depth intraslab earthquakes and arc volcanism as physical expressions of crustal and uppermost mantle metamorphism in subducting slabs Intermediate‐depth intraslab earthquakes and arc volcanism as physical expressions of crustal and uppermost mantle metamorphism in subducting slabs
We elaborate on the well-known spatial association between axc volcanoes and Wadati Benioff zones and explore in detail their genetic relationships as dual physical expressions of slab metamorphism of the oceanic crust and uppermost mantle. At hypocentral depths less than 200 km intra slab Wadati-Benioff earthquakes tend to occur near the top surfaces of slabs. Subduction of very young...
Authors
Stephen H. Kirby, E. Robert Engdahl, Roger P. Denlinger
Knowledge of the fount and the cause of disaster Knowledge of the fount and the cause of disaster
No abstract available.
Authors
William C. Evans
Exsolved magmatic fluid and its role in the formation of comb-layered quartz at the Cretaceous Logtung W-Mo deposit, Yukon Territory, Canada Exsolved magmatic fluid and its role in the formation of comb-layered quartz at the Cretaceous Logtung W-Mo deposit, Yukon Territory, Canada
Comb-layered quartz is a type of unidirectional solidification texture found at the roofs of shallow silicic intrusions that are often associated spatially with Mo and W mineralisation. The texture consists of multiple layers of euhedral, prismatic quartz crystals (Type I) that have grown on subplanar aplite substrates. The layers are separated by porphyritic aplite containing equant...
Authors
Jacob B. Lowenstern, W. David Sinclair
Earthquakes and carbon dioxide beneath Mammoth Mountain, California Earthquakes and carbon dioxide beneath Mammoth Mountain, California
No abstract available.
Authors
David P. Hill
Photographs of the 1989-90 eruptions of Redoubt Volcano, Alaska Photographs of the 1989-90 eruptions of Redoubt Volcano, Alaska
No abstract available.
Authors
A.L. Roach, Christina A. Neal, R. G. McGimsey
Hydrologic data for Long Valley Caldera, Mono County, California, 1987-93 Hydrologic data for Long Valley Caldera, Mono County, California, 1987-93
Hydrologic data were collected during 1987-93 as part of the U.S. Geological Survey's long-term Volcanic Hazards Monitoring Program of the Long Valley Caldera, Mono County, California. The data are presented in graphs or tables. Data collected for the Long Valley Hydrologic Advisory Committee monitoring program also are presented. Hydrologic data collected include continuous record of...
Authors
J. F. Howle, C. D. Farrar
The most recent eruptions of Hualalai Volcano, Hawaii; an annotated bibliography The most recent eruptions of Hualalai Volcano, Hawaii; an annotated bibliography
No abstract available.
Authors
J. P. Kauahikaua, Bobby Camara
Recurrent eruption and subsidence at the Platoro caldera complex, southeastern San Juan volcanic field, Colorado: New tales from old tuffs Recurrent eruption and subsidence at the Platoro caldera complex, southeastern San Juan volcanic field, Colorado: New tales from old tuffs
Reinterpretation of a voluminous regional ash-flow sheet (Masonic Park Tuff) as two separate tuff sheets of similar phenocryst-rich dacite erupted from separate source calderas has important implications for evolution of the multicyclic Platoro caldera complex and for caldera-forming processes generally. Masonic Park Tuff in central parts of the San Juan field, including the type area...
Authors
P. W. Lipman, M.A. Dungan, L.L. Brown, A. Deino
Volatile emissions from the crater and flank of Oldoinyo Lengai volcano, Tanzania Volatile emissions from the crater and flank of Oldoinyo Lengai volcano, Tanzania
As a comparison to airborne infrared (IR) flux measurements, ground-based sampling of fumarole and soil gases was used to characterize the quiescent degassing of CO2 from Oldoinyo Lengai volcano. Aerial and ground-based measurements are in good agreement: ∼75% of the aerially measured CO2 flux at Lengai (0.05–0.06 × 1012 mol yr−1 or 6000–7200 tonnes CO2 d−1) can be attributed to seven...
Authors
K.W. Koepenick, S.L. Brantley, J. M. Thompson, G.L. Rowe, A.A. Nyblade, C. Moshy