Publications
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Primitive magmas at five Cascade volcanic fields: Melts from hot, heterogeneous sub-arc mantle
Major and trace element concentrations, including REE by isotope dilution, and Sr, Nd, Pb, and O isotope ratios have been determined for 38 mafic lavas from the Mount Adams, Crater Lake, Mount Shasta, Medicine Lake, and Lassen volcanic fields, in the Cascade arc, northwestern part of the United States. Many of the samples have a high Mg# [100Mg/(Mg + FeT) > 60] and Ni content (>140 ppm) such that
Authors
C. R. Bacon, P. E. Bruggman, R. L. Christiansen, M.A. Clynne, J. M. Donnelly-Nolan, W. Hildreth
Living with a restless caldera: Long Valley, California
No abstract available.
Authors
David P. Hill, Roy A. Bailey, Michael L. Sorey, James W. Hendley, Peter H. Stauffer
Volcano hazards at Newberry Volcano, Oregon
Newberry volcano is a broad shield volcano located in central Oregon. It has been built by thousands of eruptions, beginning about 600,000 years ago. At least 25 vents on the flanks and summit have been active during several eruptive episodes of the past 10,000 years. The most recent eruption 1,300 years ago produced the Big Obsidian Flow. Thus, the volcano's long history and recent activity indic
Authors
David R. Sherrod, Larry G. Mastin, William E. Scott, Steven P. Schilling
Volcanic ash - danger to aircraft in the north Pacific
The world's busy air traffic corridors pass over hundreds of volcanoes capable of sudden, explosive eruptions. In the United States alone, aircraft carry many thousands of passengers and millions of dollars of cargo over volcanoes each day. Volcanic ash can be a serious hazard to aviation even thousands of miles from an eruption. Airborne ash can diminish visibility, damage flight control systems,
Authors
Christina A. Neal, Thomas J. Casadevall, Thomas P. Miller, James W. Hendley, Peter H. Stauffer
Preliminary Volcano-Hazard Assessment for Redoubt Volcano, Alaska
Redoubt Volcano is a stratovolcano located within a few hundred kilometers of more than half of the population of Alaska. This volcano has erupted explosively at least six times since historical observations began in 1778. The most recent eruption occurred in 1989-90 and similar eruptions can be expected in the future. The early part of the 1989-90 eruption was characterized by explosive emission
Authors
Christopher F. Waythomas, Joseph M. Dorava, Thomas P. Miller, Christina A. Neal, Robert G. McGimsey
Volcano and earthquake hazards in the Crater Lake region, Oregon
Crater Lake lies in a basin, or caldera, formed
by collapse of the Cascade volcano known as Mount
Mazama during a violent, climactic eruption about
7,700 years ago. This event dramatically changed the
character of the volcano so that many potential types
of future events have no precedent there. This
potentially active volcanic center is contained within
Crater Lake National Park, visited b
Authors
Charles R. Bacon, Larry G. Mastin, Kevin M. Scott, Manuel Nathenson
Lahars of Mount Pinatubo, Philippines
On June 15, 1991, Mount Pinatubo in the Philippines exploded in the second largest volcanic eruption on Earth this century. This eruption deposited more than 1 cubic mile (5 cubic kilometers) of volcanic ash and rock fragments on the volcano's slopes. Within hours, heavy rains began to wash this material down into the surrounding lowlands in giant, fast-moving mudflows called lahars. In the next f
Authors
Christopher G. Newhall, Peter H. Stauffer, James W. Hendley
The Cataclysmic 1991 Eruption of Mount Pinatubo, Philippines
The second-largest volcanic eruption of this century, and by far the largest eruption to affect a densely populated area, occurred at Mount Pinatubo in the Philippines on June 15, 1991. The eruption produced high-speed avalanches of hot ash and gas, giant mudflows, and a cloud of volcanic ash hundreds of miles across. The impacts of the eruption continue to this day.
Authors
Christopher G. Newhall, James W. Hendley, Peter H. Stauffer
Benefits of volcano monitoring far outweigh costs - the case of Mount Pinatubo
The climactic June 1991 eruption of Mount Pinatubo, Philippines, was the largest volcanic eruption in this century to affect a heavily populated area. Because it was forecast by scientists from the Philippine Institute of Volcanology and Seismology and the U.S. Geological Survey, civil and military leaders were able to order massive evacuations and take measures to protect property before the erup
Authors
Chris G. Newhall, James W. Hendley, Peter H. Stauffer
Living with volcanic risk in the Cascades
The Cascade Range of the Pacific Northwest has more than a dozen potentially active volcanoes. Cascade volcanoes tend to erupt explosively, and on average two eruptions occur per century—the most recent were at Mount St. Helens, Washington (1980–86 and 2004–8), and Lassen Peak, California (1914–17). To help protect the Pacific Northwest’s rapidly expanding population, USGS scientists at the Cascad
Authors
Daniel Dzurisin, Peter H. Stauffer, James W. Hendley
Comparative ultrastructure of two closely related thalassiosira species: Thalassiosira vulnifica (gombos) fenner and T. fasciculata Harwood et Maruyama
The distinctive morphology and relatively short geological range (3.25 to 2.5 Ma) of Thalassiosira vulniflca (Gombos) Fenner make it especially useful for Pliocene biostratigraphic studies in the Antarctic region. Thalassiosira fasciculata Harwood et Maruyama has a geological range (4.5 to 0.75 Ma) that overlaps that of T. vulnifica and it resembles this taxon in possessing prominent fultoportulae
Authors
Albert D. Mahood, John A. Barron
Characteristics of debris flows of noneruptive origin on Mount Shasta, northern California
Studies of Mount Shasta indicate that eruptive activity has occurred, on the average, once every 800 years. Debris flows and deposits of non- eruptive origin, in addition to those associated with eruptive activity (lava flows, pyroclastic flows, and ash fall), inundate the fans and channels and can endanger people or property on the flanks of the mountain. This study evaluates the source and chara
Authors
James C. Blodgett, Karen R. Poeschel, Waite R. Osterkamp