Publications
Filter Total Items: 2677
Monitoring gas emissions can help forecast volcanic eruptions
As magma ascends in active volcanoes, dissolved volatiles partition from melt into a gas phase, rise, and are released into the atmosphere from volcanic vents. The major components of high-temperature volcanic gas are typically water vapor, carbon dioxide, and sulfur dioxide.
Volcanologists have long recognized that measuring the chemical composition and emission rates of these discharged volatil
Authors
Christoph Kern, J. Maarten de Moor, Bo Galle
The 2004–2008 dome-building eruption at Mount St. Helens, Washington: Epilogue
The 2004–2008 dome-building eruption at Mount St. Helens ended during winter 2007–2008 at a time when field observations were hampered by persistent bad weather. As a result, recognizing the end of the eruption was challenging—but important for scientists trying to understand how and why long-lived eruptions end and for public officials and land managers responsible for hazards mitigation and acce
Authors
Daniel Dzurisin, Seth C. Moran, Michael Lisowski, Steve P. Schilling, Kyle R. Anderson, Cynthia A. Werner
Monitoring ground-surface heating during expansion of the Casa Diablo production well field at Mammoth Lakes, California
The Long Valley hydrothermal system supports geothermal power production from 3 binary plants (Casa Diablo) near the town of Mammoth Lakes, California. Development and growth of thermal ground at sites west of Casa Diablo have created concerns over planned expansion of a new well field and the associated increases in geothermal fluid production. To ensure that all areas of ground heating are ident
Authors
D. Bergfeld, R. Greg Vaughan, William C. Evans, Eric Olsen
Scaling and design of landslide and debris-flow experiments
Scaling plays a crucial role in designing experiments aimed at understanding the behavior of landslides, debris flows, and other geomorphic phenomena involving grain-fluid mixtures. Scaling can be addressed by using dimensional analysis or – more rigorously – by normalizing differential equations that describe the evolving dynamics of the system. Both of these approaches show that, relative to ful
Authors
Richard M. Iverson
Mechanisms and timescales of generating eruptible rhyolitic magmas at Yellowstone caldera from zircon and sanidine geochronology and geochemistry
We constrain the physical nature of the magma reservoir and the mechanisms of rhyolite generation at Yellowstone caldera via detailed characterization of zircon and sanidine crystals hosted in three rhyolites erupted during the (ca. 170 – 70 ka) Central Plateau Member eruptive episode – the most recent post-caldera magmatism at Yellowstone. We present 238U-230Th crystallization ages and trace-elem
Authors
Mark E. Stelten, Kari M. Cooper, Jorge A. Vazquez, Andrew T. Calvert, Justin G Glessner
In defense of Magnetite-Ilmenite Thermometry in the Bishop Tuff and its implication for gradients in silicic magma reservoirs
Despite claims to the contrary, the compositions of magnetite and ilmenite in the Bishop Tuff correctly record the changing conditions of T and fO2 in the magma reservoir. In relatively reduced (∆NNO < 1) siliceous magmas (e.g., Bishop Tuff, Taupo units), Ti behaves compatibly (DTi ≈ 2-3.5), leading to a decrease in TiO2 activity in the melt with cooling and fractionation. In contrast, FeTi-oxides
Authors
Bernard W Evans, Edward Hildreth, Olivier Bachmann, Bruno Scaillet
Amphibole reaction rims as a record of pre-eruptive magmatic heating: An experimental approach
Magmatic minerals record the pre-eruptive timescales of magma ascent and mixing in crustal reservoirs and conduits. Investigations of the mineral records of magmatic processes are fundamental to our understanding of what controls eruption style, as ascent rates and magma mixing processes are well known to control and/or trigger potentially hazardous explosive eruptions. Thus, amphibole reaction ri
Authors
S. H. De Angelis, J. Larsen, Michelle L. Coombs, A. Dunn, Leslie A. Hayden
Heat flux from magmatic hydrothermal systems related to availability of fluid recharge
Magmatic hydrothermal systems are of increasing interest as a renewable energy source. Surface heat flux indicates system resource potential, and can be inferred from soil CO2 flux measurements and fumarole gas chemistry. Here we compile and reanalyze results from previous CO2 flux surveys worldwide to compare heat flux from a variety of magma-hydrothermal areas. We infer that availability of wate
Authors
M. C. Harvey, J.V. Rowland, G. Chiodini, C.F. Rissmann, S. Bloomberg, P.A. Hernandez, A. Mazot, F. Viveiros, Cynthia A. Werner
Magma extrusion during the Ubinas 2013–2014 eruptive crisis based on satellite thermal imaging (MIROVA) and ground-based monitoring
After 3 years of mild gases emissions, the Ubinas volcano entered in a new eruptive phase on September 2nd, 2013. The MIROVA system (a space-based volcanic hot-spot detection system), allowed us to detect in near real time the thermal emissions associated with the eruption and provided early evidence of magma extrusion within the deep summit crater. By combining IR data with plume height, sulfur e
Authors
Diego Coppola, Orlando Macedo, Domingo Ramos, Anthony Finizola, Dario Delle Donne, Jose del Carpio, Randall A. White, Wendy McCausland, Riky Centeno, Marco Rivera, Fredy Apaza, Beto Ccallata, Wilmer Chilo, Corrado Cigolini, Marco Laiolo, Ivonne Lazarte, Roger Machaca, Pablo Masias, Mayra Ortega, Nino Puma, Edú Taipe
Linking magma transport structures at Kīlauea volcano
Identifying magma pathways is important for understanding and interpreting volcanic signals. At Kīlauea volcano, seismicity illuminates subsurface plumbing, but the broad spectrum of seismic phenomena hampers event identification. Discrete, long-period events (LPs) dominate the shallow (5-10 km) plumbing, and deep (40+ km) tremor has been observed offshore. However, our inability to routinely iden
Authors
Aaron G. Wech, Weston A. Thelen
Shifts in the eruptive styles at Stromboli in 2010–2014 revealed by ground-based InSAR data
Ground-Based Interferometric Synthetic Aperture Radar (GBInSAR) is an efficient technique for capturing short, subtle episodes of conduit pressurization in open vent volcanoes like Stromboli (Italy), because it can detect very shallow magma storage, which is difficult to identify using other methods. This technique allows the user to choose the optimal radar location for measuring the most signifi
Authors
Federico Di Traglia, Maurizio Battaglia, Teresa Nolesini, Daniela Lagomarsino, Nicola Casaglia
Volcano monitoring from space
Unlike many natural hazards, volcanoes usually give warnings of impending eruptions that can be detected from hours to years prior to any hazardous activity [Sparks et al., 2012]. The Eyjafjallajökull eruption, for example, was preceded by several discrete episodes of subsurface magma accumulation that highlighted the potential for future eruption. Once it begins, an eruption can last for up to
Authors
Michael P. Poland