Publications
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Tremor reveals stress shadowing, deep postseismic creep, and depth-dependent slip recurrence on the lower-crustal San Andreas fault near Parkfield
The 2003 magnitude 6.5 San Simeon and the 2004 magnitude 6.0 Parkfield earthquakes induced small, but significant, static stress changes in the lower crust on the central San Andreas fault, where recently detected tectonic tremor sources provide new constraints on deep fault creep processes. We find that these earthquakes affect tremor rates very differently, consistent with their differing transf
Authors
David R. Shelly, Kaj M. Johnson
Evidence of magma intrusion at Fourpeaked volcano, Alaska in 2006-2007 from a rapid-response seismic network and volcanic gases
On September 17th, 2006, Fourpeaked volcano had a widely-observed phreatic eruption. At the time, Fourpeaked was an unmonitored volcano with no known Holocene activity, based on limited field work. Airborne gas sampling began within days of the eruption and a modest seismic network was installed in stages. Vigorous steaming continued for months; however, there were no further eruptions similar in
Authors
M. Gardine, M. West, C. Werner, M. Doukas
Origin of a rhyolite that intruded a geothermal well while drilling at the Krafla volcano, Iceland
Magma flowed into an exploratory geothermal well at 2.1 km depth being drilled in the Krafla central volcano in Iceland, creating a unique opportunity to study rhyolite magma in situ in a basaltic environment. The quenched magma is a partly vesicular, sparsely phyric, glass containing ∼1.8% of dissolved volatiles. Based on calculated H2O-CO2 saturation pressures, it degassed at a pressure intermed
Authors
W.A. Elders, G.O. Fridleifsson, R.A. Zierenberg, E.C. Pope, A.K. Mortensen, A. Gudmundsson, Jacob B. Lowenstern, N.E. Marks, L. Owens, D.K. Bird, M. Reed, N.J. Olsen, P. Schiffman
Geochemistry of southern Pagan Island lavas, Mariana arc: The role of subduction zone processes
New major and trace element abundances, and Pb, Sr, and Nd isotopic ratios of Quaternary lavas from two adjacent volcanoes (South Pagan and the Central Volcanic Region, or CVR) located on Pagan Island allow us to investigate the mantle source (i.e., slab components) and melting dynamics within the Mariana intra-oceanic arc. Geologic mapping reveals a pre-caldera (780-9.4ka) and post-caldera (
Authors
J.P. Marske, A.J. Pietruszka, F. A. Trusdell, M.O. Garcia
Newberry Volcano—Central Oregon's Sleeping Giant
Hidden in plain sight, Oregon's massive Newberry Volcano is the largest volcano in the Cascades volcanic arc and covers an area the size of Rhode Island. Unlike familiar cone-shaped Cascades volcanoes, Newberry was built into the shape of a broad shield by repeated eruptions over 400,000 years. About 75,000 years ago a major explosion and collapse event created a large volcanic depression (caldera
Authors
Julie M. Donnelly-Nolan, Wendy K. Stovall, David W. Ramsey, John W. Ewert, Robert A. Jensen
Database for potential hazards from future volcanic eruptions in California
More than 500 volcanic vents have been identified in the State of California. At least 76 of these vents have erupted, some repeatedly, during the past 10,000 yr. Past volcanic activity has ranged in scale and type from small rhyolitic and basaltic eruptions through large catastrophic rhyolitic eruptions. Sooner or later, volcanoes in California will erupt again, and they could have serious impact
Authors
Melissa N. White, David W. Ramsey, C. Dan Miller
The story of the Hawaiian Volcano Observatory -- A remarkable first 100 years of tracking eruptions and earthquakes
The year 2012 marks the centennial of the Hawaiian Volcano Observatory (HVO). With the support and cooperation of visionaries, financiers, scientists, and other individuals and organizations, HVO has successfully achieved 100 years of continuous monitoring of Hawaiian volcanoes. As we celebrate this milestone anniversary, we express our sincere mahalo—thanks—to the people who have contributed to a
Authors
Janet L. Babb, James P. Kauahikaua, Robert I. Tilling
Variations in eruption style during the 1931 A.D. eruption of Aniakchak volcano, Alaska
The 1931 A.D. eruption of Aniakchak volcano, Alaska, progressed from subplinian to effusive eruptive style and from trachydacite to basaltic andesite composition from multiple vent locations. Eyewitness accounts and new studies of deposit stratigraphy provide a combined narrative of eruptive events. Additional field, compositional, grain size, componentry, density, and grain morphology data docume
Authors
Robert S. Nicholson, James E. Gardner, Christina A. Neal
Lava tube shatter rings and their correlation with lava flux increases at Kīlauea Volcano, Hawai‘i
Shatter rings are circular to elliptical volcanic features, typically tens of meters in diameter, which form over active lava tubes. They are typified by an upraised rim of blocky rubble and a central depression. Prior to this study, shatter rings had not been observed forming, and, thus, were interpreted in many ways. This paper describes the process of formation for shatter rings observed at Kīl
Authors
T.R. Orr
Volcanology curricula development aided by online educational resource
Using On-Line Volcano Monitoring Data in College and University Courses: The Volcano Exploration Project: Pu`u `Ō`ō (VEPP); Hawaii Volcanoes National Park, Hawaii, 26–30 July 2010; Volcanic activity is an excellent hook for engaging college and university students in geoscience classes. An increasing number of Internet-accessible real-time and near–real time volcano monitoring data are now availab
Authors
Michael P. Poland, Kraft Van Der Hoeven, R. Teasdale
Mapping three-dimensional surface deformation by combining multiple-aperture interferometry and conventional interferometry: Application to the June 2007 eruption of Kilauea Volcano, Hawaii
Surface deformation caused by an intrusion and small eruption during June 17-19, 2007, along the East Rift Zone of Kilauea Volcano, Hawaii, was three-dimensionally reconstructed from radar interferograms acquired by the Advanced Land Observing Satellite (ALOS) phased-array type L-band synthetic aperture radar (SAR) (PALSAR) instrument. To retrieve the 3-D surface deformation, a method that combine
Authors
H.-S. Jung, Z. Lu, J.-S. Won, Michael P. Poland, Asta Miklius
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