Publications
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Influences of organic matter and calcification rate on trace elements in aragonitic estuarine bivalve shells Influences of organic matter and calcification rate on trace elements in aragonitic estuarine bivalve shells
A suite of elements (B, Na, Mg, S, K, Ca, V, Mn, Cr, Sr, and Ba) was measured in aragonitic shells of the estuarine bivalve Corbula amurensis, the Asian clam, using the Sensitive High-Resolution Ion MicroProbe with Reverse Geometry (SHRIMP RG). Our initial intent was to explore potential geochemical proxy relationships between shell chemistry and salinity (freshwater inflow) in northern...
Authors
R.K. Takesue, C. R. Bacon, J.K. Thompson
Evolution of CO2 in Lakes Monoun and Nyos, Cameroon, before and during controlled degassing Evolution of CO2 in Lakes Monoun and Nyos, Cameroon, before and during controlled degassing
Evolution of CO2 in Lakes Monoun and Nyos (Cameroon) before and during controlled degassing is described using results of regular monitoring obtained during the last 21 years. The CO2(aq) profiles soon after the limnic eruptions were estimated for Lakes Monoun and Nyos using the CTD data obtained in October and November 1986, respectively. Based on the CO2(aq)profiles through time, the...
Authors
M. Kusakabe, T. Ohba, Issa, Y. Yoshida, H. Satake, T. Ohizumi, William C. Evans, G. Tanyileke, G.W. Kling
Geologic map of Mount St. Helens, Washington prior to the 1980 eruption Geologic map of Mount St. Helens, Washington prior to the 1980 eruption
It is rare that a geologic map exists for a volcano prior to such a catastrophic modification as that produced by the eruption of Mount St. Helens in 1980. As such, this map provides an important historical record of the volcano prior to that eruption. The map has not been reviewed or checked for conformity to USGS editorial standards or stratigraphic nomenclature, and it has not been...
Authors
Clifford A. Hopson
Modeled tephra ages from lake sediments, base of Redoubt Volcano, Alaska Modeled tephra ages from lake sediments, base of Redoubt Volcano, Alaska
A 5.6-m-long lake sediment core from Bear Lake, Alaska, located 22 km southeast of Redoubt Volcano, contains 67 tephra layers deposited over the last 8750 cal yr, comprising 15% of the total thickness of recovered sediment. Using 12 AMS 14C ages, along with the 137Cs and 210Pb activities of recent sediment, we evaluated different models to determine the age-depth relation of the core...
Authors
C.J. Schiff, D. S. Kaufman, K.L. Wallace, A. Werner, T.-L. Ku, T.A. Brown
An exact solution for ideal dam-break floods on steep slopes An exact solution for ideal dam-break floods on steep slopes
The shallow‐water equations are used to model the flow resulting from the sudden release of a finite volume of frictionless, incompressible fluid down a uniform slope of arbitrary inclination. The hodograph transformation and Riemann's method make it possible to transform the governing equations into a linear system and then deduce an exact analytical solution expressed in terms of...
Authors
C. Ancey, Richard M. Iverson, M. Rentschler, Roger P. Denlinger
Broadband seismic measurements of degassing activity associated with lava effusion at Popocatépetl Volcano, Mexico Broadband seismic measurements of degassing activity associated with lava effusion at Popocatépetl Volcano, Mexico
From November 1999 through July 2000, a broadband seismic experiment was carried out at Popocatépetl Volcano to record seismic activity over a wide period range (0.04–100 s). We present an overview of the seismicity recorded during this experiment and discuss results of analyses of long-period (LP) and very-long-period (VLP) seismic signals recorded at stations nearest to the crater over...
Authors
Alejandra Arciniega-Ceballos, Bernard A. Chouet, Phillip Dawson, Guenter Asch
Deformation of the Augustine Volcano, Alaska, 1992-2005, measured by ERS and ENVISAT SAR interferometry Deformation of the Augustine Volcano, Alaska, 1992-2005, measured by ERS and ENVISAT SAR interferometry
The Augustine Volcano is a conical-shaped, active stratovolcano located on an island of the same name in Cook Inlet, about 290 km southwest of Anchorage, Alaska. Augustine has experienced seven significant explosive eruptions - in 1812, 1883, 1908, 1935, 1963, 1976, 1986, and in January 2006. To measure the ground surface deformation of the Augustine Volcano before the 2006 eruption, we...
Authors
Chang-Wook Lee, Zhong Lu, Oh-Ig Kwoun, Joong-Sun Won
The 2005 catastrophic acid crater lake drainage, lahar, and acidic aerosol formation at Mount Chiginagak volcano, Alaska, USA: Field observations and preliminary water and vegetation chemistry results The 2005 catastrophic acid crater lake drainage, lahar, and acidic aerosol formation at Mount Chiginagak volcano, Alaska, USA: Field observations and preliminary water and vegetation chemistry results
A mass of snow and ice 400-m-wide and 105-m-thick began melting in the summit crater of Mount Chiginagak volcano sometime between November 2004 and early May 2005, presumably owing to increased heat flux from the hydrothermal system, or possibly from magma intrusion and degassing. In early May 2005, an estimated 3.8??106 m3 of sulfurous, clay-rich debris and acidic water, with an...
Authors
J.R. Schaefer, W. E. Scott, William C. Evans, J. Jorgenson, R. G. McGimsey, B. Wang
Pre-1991 sulfur transfer between mafic injections and dacite magma in the Mt. Pinatubo reservoir Pre-1991 sulfur transfer between mafic injections and dacite magma in the Mt. Pinatubo reservoir
Before the 1991–1992 activity, a large andesite lava dome belonging to the penultimate Pinatubo eruptive period (Buag ∼ 500 BP) formed the volcano summit. Buag porphyritic andesite contains abundant amphibole-bearing microgranular enclaves of basaltic–andesite composition. Buag enclaves have lower K2O and incompatible trace element (LREE, U, Th) contents than mafic pulses injected in the...
Authors
Muro A. Di, John S. Pallister, B. Villemant, Chris Newhall, M. Semet, M. Martinez, C. Mariet
A volcano rekindled: The renewed eruption of Mount St. Helens, 2004-2006 A volcano rekindled: The renewed eruption of Mount St. Helens, 2004-2006
Mount St. Helens began a dome-building eruption in September 2004 after nearly two decades of quiescence. Dome growth was initially robust, became more sluggish with time, and ceased completely in late January 2008. The volcano has been quiet again since January 2008. Professional Paper 1750 describes the first 1 1/2 years of this eruptive activity, chiefly from September 2004 until...
Authors
David R. Sherrod, William E. Scott, Peter H. Stauffer
Iron isotope fractionation during magmatic differentiation in Kilauea Iki lava lake Iron isotope fractionation during magmatic differentiation in Kilauea Iki lava lake
Magmatic differentiation helps produce the chemical and petrographic diversity of terrestrial rocks. The extent to which magmatic differentiation fractionates nonradiogenic isotopes is uncertain for some elements. We report analyses of iron isotopes in basalts from Kilauea Iki lava lake, Hawaii. The iron isotopic compositions (56Fe/54Fe) of late-stagemeltveins are 0.2 permil (per...
Authors
F.-Z. Teng, N. Dauphas, Rosalind Tuthill Helz
4th EGU Alexander von Humboldt conference - the Andes: challenge for geosciences 4th EGU Alexander von Humboldt conference - the Andes: challenge for geosciences
No abstract available.
Authors
P. Fabian, R. Garreau, Christoph Schneider, Robert I. Tilling