Publications
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Evaluation of some software measuring displacements using GPS in real-time
For the past decade, the USGS has been monitoring deformation at various locations in the western United States using continuous GPS. The main focus of these measurements are estimates of displacement averaged over one day. Essentially, these consist of recording at 30 seconds intervals the carrier-frequency phase-data (equivalent to travel-time) between a GPS receiver and the GPS satellite networ
Authors
John Langbein
Tephra deposits for the past 2600 years from Irazú Volcano, Costa Rica: Chapter 12 in Volcanic hazards in Central America
No abstract available.
Authors
S.K. Clark, M. K. Reagan, D.A. Trimble
Volcanic hazards in Central America
This volume is a sampling of current scientific work about volcanoes in Central America with specific application to hazards. The papers reflect a variety of international and interdisciplinary collaborations and employ new methods. The book will be of interest to a broad cross section of scientists, especially volcanologists. The volume also will interest students who aspire to work in the field
Hawaiian Volcano Observatory seismic data, January to December 2005
The Hawaiian Volcano Observatory (HVO) summary presents seismic data gathered during the year. The seismic summary is offered without interpretation as a source of preliminary data. It is complete in the sense that most data for events of M-1.5 routinely gathered by the Observatory are included.
The HVO summaries have been published in various forms since 1956. Summaries prior to 1974 were issu
Authors
Jennifer S. Nakata
The reawakening of Alaska's Augustine volcano
Augustine volcano, in south central Alaska, ended a 20-year period of repose on 11 January 2006 with 13 explosive eruptions in 20 days. Explosive activity shifted to a quieter effusion of lava in early February, forming a new summit lava dome and two short, blocky lava flows by late March (Figure 1).
The eruption was heralded by eight months of increasing seismicity, deformation, gas emission, and
Authors
John A. Power, Christopher J. Nye, Michelle L. Coombs, Rick L. Wessels, Peter F. Cervelli, Jon Dehn, Kristi L. Wallace, Jeffrey T. Freymueller, Michael P. Doukas
Toward "Supervolcano" technology
In addition to depicting the ultimate volcano-eruption horror story, the recent Discovery Channel/BBC coproduction “Supervolcano” speculates about what technology will be available to the geophysicist in 2025 to monitor active volcanoes. The result is a fictional Virtual Geophysical Laboratory that, when fed the right data, predicts eruption scenarios, thereby providing information to help guide c
Authors
Gillian R. Foulger
Chemical analyses and K-Ar ages of samples from 13 drill holes, Medicine Lake volcano, California
Chemical analyses and K-Ar ages are presented for rocks sampled from drill holes at Medicine Lake volcano, northern California. A location map and a cross-section are included, as are separate tables for drill hole information, major and trace element data, and for K-Ar dates.
Authors
Julie M. Donnelly-Nolan
USGS-NoGaDat - A global dataset of noble gas concentrations and their isotopic ratios in volcanic systems
The database (Version 1.0) is a MS-Excel file that contains close to 5,000 entries of published information on noble gas concentrations and isotopic ratios from volcanic systems in Mid-Ocean ridges, ocean islands, seamounts, and oceanic and continental arcs (location map). Where they were available we also included the isotopic ratios of strontium, neodymium, and carbon. The database is sub-divide
Authors
Atosa A. Abedini, S. Hurwitz, William C. Evans
Preface
No abstract available.
Authors
João Carlos Nunes, Robert I. Tilling, Gudmundur E. Sigvaldason
Dynamics of diffusive bubble growth and pressure recovery in a bubbly rhyolitic melt embedded in an elastic solid
We present a model of gas exsolution and bubble expansion in a melt supersaturated in response to a sudden pressure drop. In our model, the melt contains a suspension of gas bubbles of identical sizes and is encased in a penny-shaped crack embedded in an elastic solid. The suspension is modeled as a three-dimensional lattice of spherical cells with slight overlap, where each elementary cell consis
Authors
Bernard A. Chouet, Phillip B. Dawson, Masaru Nakano
Aftershock decay, productivity, and stress rates in Hawaii: Indicators of temperature and stress from magma sources
We examined dozens of aftershock sequences in Hawaii in terms of Gutenberg-Richter and modified Omori law parameters. We studied p, the rate of aftershock decay; Ap, the aftershock productivity, defined as the observed divided by the expected number of aftershocks; and c, the time delay when aftershock rates begin to fall. We found that for earthquakes shallower than 20 km, p values >1.2 are near
Authors
Fred W. Klein, Tom Wright, Jennifer Nakata
Borehole dilatometer installation, operation, and maintenance at sites in Hawaii
In response to concerns about the potential hazard of Mauna Loa volcano in Hawaii, the USGS began efforts in 1998 to add four high-resolution borehole sites. Located at these sites are; strainmeters, tiltmeters, seismometers, accelerometers and other instrumentation. These instruments are capable of providing continuous monitoring of the magma movement under Mauna Loa. Each site was planned to pro
Authors
G.D. Myren, M.J.S. Johnston, R.J. Mueller