Publications
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Peak flow responses to landscape disturbances caused by the cataclysmic 1980 eruption of Mount St. Helens, Washington Peak flow responses to landscape disturbances caused by the cataclysmic 1980 eruption of Mount St. Helens, Washington
Years of discharge measurements that precede and follow the cataclysmic 1980 eruption of Mount St. Helens, Washington, provide an exceptional opportunity to examine the responses of peak flows to abrupt, widespread, devastating landscape disturbance. Multiple basins surrounding Mount St. Helens (300–1300 km2 drainage areas) were variously disturbed by: (1) a debris avalanche that buried...
Authors
Jon J. Major, Linda E. Mark
Interferometric synthetic aperture radar: Building tomorrow's tools today Interferometric synthetic aperture radar: Building tomorrow's tools today
A synthetic aperture radar (SAR) system transmits electromagnetic (EM) waves at a wavelength that can range from a few millimeters to tens of centimeters. The radar wave propagates through the atmosphere and interacts with the Earth’s surface. Part of the energy is reflected back to the SAR system and recorded. Using a sophisticated image processing technique, called SAR processing...
Authors
Zhong Lu
Preliminary Geologic Map of Mount Pagan Volcano, Pagan Island, Commonwealth of the Northern Mariana Islands Preliminary Geologic Map of Mount Pagan Volcano, Pagan Island, Commonwealth of the Northern Mariana Islands
Pagan Island is the subaerial portion of two adjoining Quaternary stratovolcanoes near the middle of the active Mariana Arc, [FAT1]north of Saipan. Pagan and the other volcanic islands that constitute part of the Arc form the northern half of the East Mariana Ridge[FAT2], which extends about 2-4 km above the ocean floor. The > 6-km-deep Mariana Trench adjoins the East Mariana Ridge on...
Authors
Frank A. Trusdell, Richard B. Moore, Maurice K. Sako
Perspectives on basaltic magma crystallization and differentiation: Lava-lake blocks erupted at Mauna Loa volcano summit, Hawaii Perspectives on basaltic magma crystallization and differentiation: Lava-lake blocks erupted at Mauna Loa volcano summit, Hawaii
Explosive eruptions at Mauna Loa summit ejected coarse-grained blocks (free of lava coatings) from Moku'aweoweo caldera. Most are gabbronorites and gabbros that have 0–26 vol.% olivine and 1–29 vol.% oikocrystic orthopyroxene. Some blocks are ferrogabbros and diorites with micrographic matrices, and diorite veins (≤2 cm) cross-cut some gabbronorites and gabbros. One block is an open...
Authors
Renee L. McCarter, R.V. Fodor, Frank A. Trusdell
Abrupt transitions during sustained explosive eruptions: Examples from the 1912 eruption of Novarupta, Alaska Abrupt transitions during sustained explosive eruptions: Examples from the 1912 eruption of Novarupta, Alaska
Plinian/ignimbrite activity stopped briefly and abruptly 16 and 45 h after commencement of the 1912 Novarupta eruption defining three episodes of explosive volcanism before finally giving way after 60 h to effusion of lava domes. We focus here on the processes leading to the termination of the second and third of these three episodes. Early erupted pumice from both episodes show a very...
Authors
N.K. Adams, Bruce F. Houghton, W. Hildreth
Eruptive history and geochronology of Mount Mazama and the Crater Lake region, Oregon Eruptive history and geochronology of Mount Mazama and the Crater Lake region, Oregon
Geologic mapping, K-Ar, and 40Ar/39Ar age determinations, supplemented by paleomagnetic measurements and geochemical data, are used to quantify the Quaternary volcanic history of the Crater Lake region in order to define processes and conditions that led to voluminous explosive eruptions. The Cascade arc volcano known as Mount Mazama collapsed during its climactic eruption of ∼50 km3 of...
Authors
Charles R. Bacon, Marvin A. Lanphere
Isotope geochemistry of early Kilauea magmas from the submarine Hilina bench: The nature of the Hilina mantle component 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...
Authors
Jun-Ichi Kimura, Thomas W. Sisson, Natsuko Nakano, Michelle L. Coombs, Peter W. Lipman
Inflation model of Uzon caldera, Kamchatka, constrained by satellite radar interferometry observations Inflation model of Uzon caldera, Kamchatka, constrained by satellite radar interferometry observations
We analyzed RADARSAT-1 synthetic aperture radar (SAR) data to compute interferometric SAR (InSAR) images of surface deformation at Uzon caldera, Kamchatka, Russia. From 2000 to 2003 approximately 0.15 m of inflation occurred at Uzon caldera, extending beneath adjacent Kikhpinych volcano. This contrasts with InSAR data showing no significant deformation during either the 1999 to 2000, or...
Authors
Paul Lundgren, Zhong Lu
Comparison of COSPEC and two miniature ultraviolet spectrometer systems for SO2 measurements using scattered sunlight Comparison of COSPEC and two miniature ultraviolet spectrometer systems for SO2 measurements using scattered sunlight
The correlation spectrometer (COSPEC), the principal tool for remote measurements of volcanic SO2, is rapidly being replaced by low-cost, miniature, ultraviolet (UV) spectrometers. We compared two of these new systems with a COSPEC by measuring SO2 column amounts at Kīlauea Volcano, Hawaii. The two systems, one calibrated using in-situ SO2 cells, and the other using a calibrated...
Authors
Tamar Elias, A. Jeff Sutton, Clive Oppenheimer, Keith A. Horton, Harold Garbeil, Vitchko Tsanev, Andrew J.S. McGonigle, Glyn Williams-Jones
Calculated volumes of individual shield volcanoes at the young end of the Hawaiian Ridge Calculated volumes of individual shield volcanoes at the young end of the Hawaiian Ridge
High-resolution multibeam bathymetry and a digital elevation model of the Hawaiian Islands are used to calculate the volumes of individual shield volcanoes and island complexes (Niihau, Kauai, Oahu, the Maui Nui complex, and Hawaii), taking into account subsidence of the Pacific plate under the load of the Hawaiian Ridge. Our calculated volume for the Island of Hawaii and its submarine...
Authors
Joel E. Robinson, Barry W. Eakins
Constraints on the mechanism of long-term, steady subsidence at Medicine Lake volcano, northern California, from GPS, leveling, and InSAR Constraints on the mechanism of long-term, steady subsidence at Medicine Lake volcano, northern California, from GPS, leveling, and InSAR
Leveling surveys across Medicine Lake volcano (MLV) have documented subsidence that is centered on the summit caldera and decays symmetrically on the flanks of the edifice. Possible mechanisms for this deformation include fluid withdrawal from a subsurface reservoir, cooling/crystallization of subsurface magma, loading by the volcano and dense intrusions, and crustal thinning due to...
Authors
Michael P. Poland, Roland Burgmann, Daniel Dzurisin, Michael Lisowski, Timothy Masterlark, Susan Owen, Jonathan Fink
Cosmogenic 3He production rates revisited from evidences of grain size dependent release of matrix-sited helium Cosmogenic 3He production rates revisited from evidences of grain size dependent release of matrix-sited helium
Measurements of the cosmogenic 3He (3Hec) content of various size aliquots of exposed olivines show that the fine fraction (
Authors
P.-H. Blard, R. Pik, J. Lave, D. Bourles, P.G. Burnard, R. Yokochi, B. Marty, F. Trusdell