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Volcano monitoring

Volcanoes are not randomly distributed over the Earth's surface. Most are concentrated on the edges of continents, along island chains, or beneath the sea where they form long mountain ranges. More than half of the world's active volcanoes above sea level encircle the Pacific Ocean (see Fig. 1). The concept of plate tectonics explains the locations of volcanoes and their relationship to other larg
Authors
James G. Smith, Jonathan Dehn, Richard P. Hoblitt, Richard G. Lahusen, Jacob B. Lowenstern, Seth C. Moran, Lindsay McClelland, Kenneth A. McGee, Manuel Nathenson, Paul G. Okubo, John S. Pallister, Michael P. Poland, John A. Power, David J. Schneider, Thomas W. Sisson

Illuminating Northern California’s Active Faults

Newly acquired light detection and ranging (lidar) topographic data provide a powerful community resource for the study of landforms associated with the plate boundary faults of northern California (Figure 1). In the spring of 2007, GeoEarthScope, a component of the EarthScope Facility construction project funded by the U.S. National Science Foundation, acquired approximately 2000 square kilometer
Authors
Carol S. Prentice, Christopher J. Crosby, Caroline S. Whitehill, J. Ramon Arrowsmith, Kevin P. Furlong, David A. Philips

Addressing geohazards through ocean drilling

No abstract available. 
Authors
J.K. Morgan, Eli Silver, Angelo Camerlenghi, Brandon Dugan, Stephen H. Kirby, Craig Shipp, Kiyoshi Suyehiro

New substorm index derived from high-resolution geomagnetic field data at low latitude and its comparison with AE and ASY indices

High-resolution geomagnetic field data (i.e., ≤5 seconds) have recently become more commonly used by space physicists. The data permit the identification of Pi2 pulsations, having periods of 40-150 seconds and irregular waveforms. Pulsations of this type appear clearly in time series from mid- and low-latitude ground stations on the nightside at substorm onset. Therefore, with data from multiple o
Authors
M. Nose, T. Iyemori, M. Takeda, H. Toh, T. Ookawa, G. Cifuentes-Nava, J. Matzka, Jeffrey J. Love, H. McCreadie, M. K. Tunçer, J. J. Curto

Absolute Measurement Session XIII IAGA Workshop Boulder Magnetic Observatory

The absolute measurement session of the XIII IAGA Workshop was held at the Boulder Magnetic Observatory June 10-13, 2008. Approximately 85 people attended this session. The main focus of the session was for observers to make and compare measurements using DIFlux magnetometers. The session also included absolute measurement training, with lectures and practical training. Also included were data pro
Authors
A. Berarducci, Andy Woods

Movement triggers and remediation in a fracture-dominated translational landslide at the Oregon coast

The Johnson Creek landslide is a translational slide in seaward dipping Miocene siltstone and sandstone (Astoria Formation) and an overlying Quaternary marine terrace deposit. The slide terminates in a sea cliff and has a hummocky to nearly horizontal ground surface. The basal slide plane, however, slopes subparallel to the dip of the Miocene rocks, except beneath the back-tilted toe blocks where
Authors
George R. Priest, Jonathan Allan, Alan Niem, Wendy A. Niem, Stephen E. Dickenson

Missing data and the accuracy of magnetic-observatory hour means

Analysis is made of the accuracy of magnetic-observatory hourly means constructed from definitive minute data having missing values (gaps). Bootstrap sampling from different data-gap distributions is used to estimate average errors on hourly means as a function of the number of missing data. Absolute and relative error results are calculated for horizontal-intensity, declination, and vertical-comp
Authors
Jeffrey J. Love

Floods of water and lava in the Columbia River Basin: Analogs for Mars

The Columbia River Basin (CRB) is home to the best studied examples of two of the most spectacular geologic processes on Earth and Mars: flood volcanism and catastrophic water floods. Additionally, features formed by a variety of eolian, glacial, tectonic, and mass-wasting processes can also be seen in the CRB. These terrains provide exceptional terrestrial analogs for the study of similar process
Authors
Laszlo P. Keszthelyi, Victor R. Baker, Windy L. Jaeger, David R. Gaylord, Bruce Bjornstad, Noam Greenbaum, Stephen Self, Thorvaldur Thordarson, Naomi Porat, Marek G. Zreda

Volcano deformation and gravity workshop synopsis and outcomes: The 2008 volcano deformation and temporal gravity change workshop

A volcano workshop was held in Washington State, near the U.S. Geological Survey (USGS) Cascades Volcano Observatory. The workshop, hosted by the USGS Volcano Hazards Program (VHP), included more than 40 participants from the United States, the European Union, and Canada. Goals were to promote (1) collaboration among scientists working on active volcanoes and (2) development of new tools for study
Authors
Daniel Dzurisin, Zhong Lu

Total field sensor comparison

During the XIIIth IAGA Workshop (hereafter referred to as “the workshop"), several total field comparison measurements were conducted at the Boulder Magnetic Observatory (BOU). The purpose of these tests was to look for errors within the total field instruments which are considered “absolutes” instruments. The total field measurement is a critical component of the absolute measurement computation.
Authors
Tim White

Earthquake Spectra at 25

No abstract available.
Authors
Charles C. Thiel, James E. Beavers, Jack P. Moehle, Roger D. Borcherdt, Farzad Naeim, Polat Gülkan
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