Publications
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Landscape response to deglaciation in a high relief, monsoon-influenced alpine environment, Langtang Himal, Nepal
Significant glacial fluctuations and rapid paraglacial reworking of glacigenic sediments characterize the Middle and Late Holocene of the Langtang Khola Valley, Central Nepal Himalaya. Geomorphic mapping and beryllium-10 cosmogenic radionuclide (CRN) dating of moraines and paraglacial fans were undertaken to test the existing paraglacial fan, terrace and moraine chronologies. The new...
Authors
P.L. Barnard, L.A. Owen, R.C. Finkel, K. Asahi
Ground deformation associated with the precursory unrest and early phases of the January 2006 eruption of Augustine volcano, Alaska
On January 11, 2006 Augustine Volcano erupted after nearly 20 years of quiescence. Global Positioning System (GPS) instrumentation at Augustine, consisting of six continuously recording, telemetered receivers, measured clear precursory deformation consistent with a source of inflation or pressurization beneath the volcano's summit at a depth of around sea level. Deformation began in...
Authors
P.F. Cervelli, T. Fournier, Jeffrey T. Freymueller, J.A. Power
The heartbeat of the volcano: The discovery of episodic activity at Prometheus on Io
The temporal signature of thermal emission from a volcano is a valuable clue to the processes taking place both at and beneath the surface. The Galileo Near Infrared Mapping Spectrometer (NIMS) observed the volcano Prometheus, on the jovian moon Io, on multiple occasions between 1996 and 2002. The 5 micron (μm) brightness of this volcano shows considerable variation from orbit to orbit...
Authors
Ashley G. Davies, Lionel Wilson, Dennis Matson, Giovanni Leone, Laszlo P. Keszthelyi, Windy L. Jaeger
Palaeomagnetic intensities from 14C-dated lava flows on the Big Island, Hawaii: 0-21 kyr
Thellier–Thellier experiments were carried out on 216 lava samples collected by the USGS on the Big Island. 35 individual flows from the Kilauea, Mauna Loa and Hualalai volcanoes are represented and independent radiocarbon dating of the flows yields absolute ages ranging from 290 to 20,240 yrs old. The palaeomagnetic analysis was carried out at the Laboratoire des Sciences du Climat et...
Authors
Nicola Pressling, Carlo Laj, Catherie Kissel, Duane E. Champion, David Gubbins
Remote sensing studies of the Dionysius region of the Moon
The Dionysius region is located near the western edge of Mare Tranquillitatis and is centered on Dionysius crater, which exhibits a well-developed dark ray system. Proposed origins for these dark rays included impact melt deposits and dark primary ejecta. The region also contains extensive deposits of Cayley-type light plains. Clementine multispectral images and a variety of spacecraft...
Authors
Thomas A. Giguere, B. Ray Hawke, Lisa R. Gaddis, David T. Blewett, J. J. Gillis-Davis, Paul G. Lucey, G.A. Smith, P. D. Spudis, G.J. Taylor
Size distribution of submarine landslides and its implication to tsunami hazard in Puerto Rico
We have established for the first time a size frequency distribution for carbonate submarine slope failures. Using detailed bathymetry along the northern edge of the carbonate platform north of Puerto Rico, we show that the cumulative distribution of slope failure volumes follows a power-law distribution. The power-law exponent of this distribution is similar to those for rock falls on...
Authors
Uri S. ten Brink, E.L. Geist, B.D. Andrews
Abrupt transitions during sustained explosive eruptions: Examples from the 1912 eruption of Novarupta, Alaska
Plinian/ignimbrite activity stopped briefly and abruptly 16 and 45 h after commencement of the 1912 Novarupta eruption defining three episodes of explosive volcanism before finally giving way after 60 h to effusion of lava domes. We focus here on the processes leading to the termination of the second and third of these three episodes. Early erupted pumice from both episodes show a very...
Authors
N.K. Adams, Bruce F. Houghton, W. Hildreth
Are migrating raptors guided by a geomagnetic compass?
We tested whether routes of raptors migrating over areas with homogeneous topography follow constant geomagnetic courses more or less closely than constant geographical courses. We analysed the routes taken over land of 45 individual raptors tracked by satellite-based radiotelemetry: 25 peregrine falcons, Falco peregrinus, on autumn migration between North and South America, and seven...
Authors
Kasper Thorup, Mark R. Fuller, T. Alerstam, M. Hake, N. Kjellen, R. Standberg
Interferometric synthetic aperture radar: Building tomorrow's tools today
A synthetic aperture radar (SAR) system transmits electromagnetic (EM) waves at a wavelength that can range from a few millimeters to tens of centimeters. The radar wave propagates through the atmosphere and interacts with the Earth’s surface. Part of the energy is reflected back to the SAR system and recorded. Using a sophisticated image processing technique, called SAR processing...
Authors
Zhong Lu
Acoustic stratigraphy of Bear Lake, Utah-Idaho: late Quaternary sedimentation patterns in a simple half-graben
A 277-km network of high-resolution seismic-reflection profiles, supplemented with a sidescan-sonar mosaic of the lake floor, was collected in Bear Lake, Utah–Idaho, in order to explore the sedimentary framework of the lake's paleoclimate record. The acoustic stratigraphy is tied to a 120 m deep, continuously cored drill hole in the lake. Based on the age model for the drill core, the...
Authors
Steven M. Colman
Probabilistic analysis of tsunami hazards
Determining the likelihood of a disaster is a key component of any comprehensive hazard assessment. This is particularly true for tsunamis, even though most tsunami hazard assessments have in the past relied on scenario or deterministic type models. We discuss probabilistic tsunami hazard analysis (PTHA) from the standpoint of integrating computational methods with empirical analysis of...
Authors
E.L. Geist, T. Parsons
Puhimau thermal area: a window into the upper east rift zone of Kilauea Volcano, Hawaii?
We report the results of two soil CO2 efflux surveys by the closed chamber circulation method at the Puhimau thermal area in the upper East Rift Zone (ERZ) of Kilauea volcano, Hawaii. The surveys were undertaken in 1996 and 1998 to constrain how much CO2 might be reaching the ERZ after degassing beneath the summit caldera and whether the Puhimau thermal area might be a significant...
Authors
K.A. McGee, A. J. Sutton, T. Elias, M.P. Doukas, T.M. Gerlach