Publications
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Ages of the granitic basement of Long Valley Caldera, California, USA, and siting of the Quaternary granite-rhyolite pluton Ages of the granitic basement of Long Valley Caldera, California, USA, and siting of the Quaternary granite-rhyolite pluton
The leucogranitic crystal-mush pluton beneath the iconic Long Valley Caldera, California, USA, released >820 km3 of crystal-poor Pleistocene rhyolite, which was hosted by numerous Mesozoic granitic plutons, only a few of which had been dated until now. Reported here are U-Pb zircon ages, determined by sensitive high-resolution ion microprobe−reverse geometry (SHRIMP-RG), for 11...
Authors
Edward Hildreth, Judith E. Fierstein, Jorge A. Vazquez
Out of the frying pan and into the fire: Effects of volcanic heat and other stressors on the conservation of a critically endangered plant in Hawaiʻi Out of the frying pan and into the fire: Effects of volcanic heat and other stressors on the conservation of a critically endangered plant in Hawaiʻi
Loss of local biodiversity resulting from abrupt environmental change is a significant environmental problem throughout the world. Extinctions of plants are particularly important yet are often overlooked. Drawing from a case in Hawai‘i, a global hotspot for plant and other extinctions, we demonstrate an effort to better understand and determine priorities for the management of an...
Authors
Nathan S. Gill, Jeff Stallman, Linda Pratt, Jennifer L. Lewicki, Tamar Elias, Patricia A. Nadeau, Stephanie G. Yelenik
Geologic map of Okmok Volcano Geologic map of Okmok Volcano
The geologic map and description of map units presented here cover approximately 880 km2 of northeastern Umnak Island, Aleutian Islands, Alaska. This report focuses on Okmok Volcano and its eruptive products and updates the mid-20th-century geologic map of Byers (1959). Mapped deposits reflect the state of the volcano just prior to the 2008 eruption. Published information about other...
Authors
Jessica Larsen, Christina A. Neal, Janet Schaefer, Christopher J. Nye
The presence of silicate melt may enhance rates of cation diffusion in olivine The presence of silicate melt may enhance rates of cation diffusion in olivine
Olivine is commonly used as a ‘crystal clock’ to extract timescales relevant to pre-eruptive perturbations within mafic magmatic systems. Diffusion chronometry applications require accurate calibrations for the rates at which Fe-Mg or other commonly measured elements like Ni, Mn, and Ca diffuse through the crystal lattice. In the past, these rates have been mainly characterized using...
Authors
Thomas Shea, Dawn Catherine Sweeney Ruth, Michael Jollands, Kenta Ohtaki, Hope Ishii, John Bradley
Barometers behaving badly: Assessing the influence of analytical and experimental uncertainty on clinopyroxene thermobarometry calculations at crustal conditions Barometers behaving badly: Assessing the influence of analytical and experimental uncertainty on clinopyroxene thermobarometry calculations at crustal conditions
The composition of clinopyroxene and clinopyroxene-liquid (Cpx-Liq) pairs are frequently used to calculate crystallization/equilibration pressures in igneous systems. While canonical uncertainties are often assigned to calculated pressures based on fits to calibration or test datasets, the sources of these uncertainties (and thus ways to reduce them) have not been rigorously assessed. We...
Authors
Penny E. Wieser, Adam J.R. Kent, Christy B. Till, J. Donovan, David A. Neave, Dawnika L. Blatter, Michael J. Krawczynski
The Pāhala swarm of earthquakes in Hawai‘i The Pāhala swarm of earthquakes in Hawai‘i
No abstract available.
Authors
Ashton F. Flinders
Detailed 40Ar/39Ar geochronology of the Loyalty and Three Kings Ridges clarifies the extent and sequential development of Eocene to Miocene southwest Pacific remnant volcanic arcs Detailed 40Ar/39Ar geochronology of the Loyalty and Three Kings Ridges clarifies the extent and sequential development of Eocene to Miocene southwest Pacific remnant volcanic arcs
The 2015 VESPA voyage (Volcanic Evolution of South Pacific Arcs) was a seismic and rock dredging expedition to the Loyalty and Three Kings Ridges and South Fiji Basin. In this paper we present 33 40Ar/39Ar, 22 micropaleontological, and two U/Pb ages for igneous and sedimentary rocks from 33 dredge sites in this little-studied part of the southwest Pacific Ocean. Igneous rocks include...
Authors
Phillip B. Gans, Nick Mortimer, M. Patriat, Rose E. Turnbull, M.P. Crundwell, A. Agranier, Andrew T. Calvert, G. Seward, Samuel Etienne, P.M.J. Durance, H.J. Campbell, Julien Collot
Optimizing satellite resources for the global assessment and mitigation of volcanic hazards—Suggestions from the USGS Powell Center Volcano Remote Sensing Working Group Optimizing satellite resources for the global assessment and mitigation of volcanic hazards—Suggestions from the USGS Powell Center Volcano Remote Sensing Working Group
A significant number of the world’s approximately 1,400 subaerial volcanoes with Holocene eruptions are unmonitored by ground-based sensors yet constitute a potential hazard to nearby residents and infrastructure, as well as air travel and global commerce. Data from an international constellation of more than 60 current satellite instruments provide a cost-effective means of tracking...
Authors
M. E. Pritchard, Michael Poland, K. Reath, B. Andrews, M. Bagnardi, J. Biggs, S. Carn, D. Coppola, S.K. Ebmeier, M.A. Furtney, T. Girona, J. Griswold, T. Lopez, P. Lundgren, S. Ogburn, M. Pavolonis, E. Rumpf, G. Vaughan, C. Wauthier, R. Wessels, R. Wright, K.R. Anderson, M.G. Bato, A. Roman
Lava-ice interactions during historical eruptions of Veniaminof Volcano, Alaska and the potential for meltwater floods and lahars Lava-ice interactions during historical eruptions of Veniaminof Volcano, Alaska and the potential for meltwater floods and lahars
Veniaminof Volcano on the Alaska Peninsula of southwest Alaska is one of a small group of ice-clad volcanoes globally that erupts lava flows in the presence of glacier ice. Here, we describe the nature of lava-ice-snow interactions that have occurred during historical eruptions of the volcano since 1944. Lava flows with total volumes on the order of 0.006 km3 have been erupted in 1983...
Authors
Christopher F. Waythomas, Benjamin R Edwards, Thomas P Miller, Robert G. McGimsey
Effects of structure and volcanic stratigraphy on groundwater and surface water flow: Hat Creek basin, California, USA Effects of structure and volcanic stratigraphy on groundwater and surface water flow: Hat Creek basin, California, USA
Hydrogeologic systems in the southern Cascade Range in California (USA) develop in volcanic rocks where morphology, stratigraphy, extensional structures, and attendant basin geometry play a central role in groundwater flow paths, groundwater/surface-water interactions, and spring discharge locations. High-volume springs (greater than 3 m3/s) flow from basin-filling (
Authors
Marina Francesca Marcelli, Erick R. Burns, L.J. Patrick Muffler, Andrew J Meigs, Jennifer A. Curtis, Christian E. Torgersen
Understanding and modeling tephra transport: Lessons learned from the 18 May 1980 eruption of Mount St. Helens Understanding and modeling tephra transport: Lessons learned from the 18 May 1980 eruption of Mount St. Helens
Discoveries made during the 18 May 1980 eruption of Mount St. Helens advanced our understanding of tephra transport and deposition in fundamental ways. The eruption enabled detailed, quantitative observations of downwind cloud movement and particle sedimentation, along with the dynamics of co-pyroclastic-density current (PDC) clouds lofted from ground-hugging currents. The deposit was...
Authors
Larry G. Mastin, Steven Carey, Alexa R. Van Eaton, Julia Eychenne, Russell Sparks
Precaldera mafic magmatism at Long Valley, California: Magma-tectonic siting and incubation of the Great Rhyolite System Precaldera mafic magmatism at Long Valley, California: Magma-tectonic siting and incubation of the Great Rhyolite System
The iconic volcanic center at Long Valley has released ∼820 km3 of rhyolite in at least 110 eruptions. From 2.2 Ma until 0.23 Ma, products were exclusively rhyolitic, and ∼ 700 km3 were high-silica rhyolite severely depleted in Sr, Ba, and Eu. The rhyolitic interval was preceded by an interval from 3.9 to 2.6 Ma with numerous basalt-andesite-dacite eruptions accompanied by no rhyolite at...
Authors
Edward Hildreth, Judith E. Fierstein, Andrew T. Calvert