Publications
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Borehole observations of continuous strain and fluid pressure: Chapter 9 Borehole observations of continuous strain and fluid pressure: Chapter 9
Strain is expansion, contraction, or distortion of the volcanic edifice and surrounding crust. As a result of magma movement, volcanoes may undergo enormous strain prior to and during eruption. Global Positioning System (GPS) observations can in principle be used to determine strain by taking the difference between two nearby observations and dividing by the distance between them. Two...
Authors
Evelyn A. Roeloffs, A. T. Linde
Explosive eruptive record in the Katmai region, Alaska Peninsula: An overview Explosive eruptive record in the Katmai region, Alaska Peninsula: An overview
At least 15 explosive eruptions from the Katmai cluster of volcanoes and another nine from other volcanoes on the Alaska Peninsula are preserved as tephra layers in syn- and post-glacial (Last Glacial Maximum) loess and soil sections in Katmai National Park, AK. About 400 tephra samples from 150 measured sections have been collected between Kaguyak volcano and Mount Martin and from...
Authors
Judy Fierstein
Magmatic gas efflux at the Ukinrek Maars, Alaska Magmatic gas efflux at the Ukinrek Maars, Alaska
No abstract available.
Authors
Deborah Bergfeld, W. C. Evans, A.G. Hunt, R. G. McGimsey
Late pleistocene and holocene caldera-forming eruptions of Okmok Caldera, Aleutian Islands, Alaska Late pleistocene and holocene caldera-forming eruptions of Okmok Caldera, Aleutian Islands, Alaska
This chapter contains sections titled: Introduction Geologic setting Field and Analytical Methods Results Discussion Conclusions
Authors
Jessica F. Larsen, Christina A. Neal, Janet Schaefer, Jim Beget, Chris Nye
Volcano-electromagnetic effects Volcano-electromagnetic effects
Volcano-electromagnetic effects—electromagnetic (EM) signals generated by volcanic activity—derive from a variety of physical processes. These include piezomagnetic effects, electrokinetic effects, fluid vaporization, thermal demagnetization/remagnetization, resistivity changes, thermochemical effects, magnetohydrodynamic effects, and blast-excited traveling ionospheric disturbances...
Authors
Malcolm J. S. Johnston
Ground-coupled acoustic airwaves from Mount St. Helens provide constraints on the May 18, 1980 eruption Ground-coupled acoustic airwaves from Mount St. Helens provide constraints on the May 18, 1980 eruption
The May 18, 1980 Mount St. Helens eruption perturbed the atmosphere and generated atmosphere-to-ground coupled airwaves, which were recorded on at least 35 seismometers operated by the Pacific Northwest Seismograph Network (PNSN). From 102 distinct travel time picks we identify coherent airwaves crossing Washington State primarily to the north and east of the volcano. The travel time...
Authors
J.B. Johnson, S. D. Malone
Volcanic eruptions, hazards, and mitigation Volcanic eruptions, hazards, and mitigation
No abstract available.
Authors
J. Feldman, R.I. Tilling
Observations of volcanic tremor during January-February 2005 eruption of Mt. Veniaminof, Alaska Observations of volcanic tremor during January-February 2005 eruption of Mt. Veniaminof, Alaska
Mt. Veniaminof, Alaska Peninsula, is a stratovolcano with a summit ice-filled caldera containing a small intracaldera cone and active vent. From January 2 to February 21, 2005, Mt. Veniaminof erupted. The eruption was characterized by numerous small ash emissions (VEI 0 to 1) and accompanied by low-frequency earthquake activity and volcanic tremor. We have performed spectral analyses of...
Authors
Slivio De Angelis, Stephen R. McNutt
Analytical volcano deformation source models Analytical volcano deformation source models
Primary volcanic landforms are created by the ascent and eruption of magma. The ascending magma displaces and interacts with surrounding rock and fluids as it creates new pathways, flows through cracks or conduits, vesiculates, and accumulates in underground reservoirs. The formation of new pathways and pressure changes within existing conduits and reservoirs stress and deform the...
Authors
Michael Lisowski
Predicting and validating the motion of an ash cloud during the 2006 eruption of Mount Augustine volcano Predicting and validating the motion of an ash cloud during the 2006 eruption of Mount Augustine volcano
On 11 January 2006, Mount Augustine volcano in southern Alaska began erupting after 20- year repose. The Anchorage Forecast Office of the National Weather Service (NWS) issued an advisory on 28 January for Kodiak City. On 31 January, Alaska Airlines cancelled all flights to and from Anchorage after multiple advisories from the NWS for Anchorage and the surrounding region. The Alaska...
Authors
Richard L. Collins, Javier Fochesatto, Kenneth Sassen, Peter W. Webley, David E. Atkinson, Kenneson G. Dean, Catherine F. Cahill, Kohei Mizutani
Extensive hydrothermal rock alteration in a low pH, steam-heated environment--Hot Springs Basin, Yellowstone National Park Extensive hydrothermal rock alteration in a low pH, steam-heated environment--Hot Springs Basin, Yellowstone National Park
No abstract available.
Authors
S. Hurwitz, J. B. Lowenstern, D. Bergfeld, C. Werner, H. Heasler, C. Jaworowski
Incremental assembly and prolonged consolidation of Cordilleran magma chambers--Evidence from the Southern Rocky Mountain volcanic field Incremental assembly and prolonged consolidation of Cordilleran magma chambers--Evidence from the Southern Rocky Mountain volcanic field
Recent inference that Mesozoic Cordilleran plutons grew incrementally during >106 yr intervals, without the presence of voluminous eruptible magma at any stage, minimizes close associations with large ignimbrite calderas. Alternatively, Tertiary ignimbrites in the Rocky Mountains and elsewhere, with volumes of 1–5 × 103 km3, record multistage histories of magma accumulation...
Authors
Peter W. Lipman