Publications
Filter Total Items: 7225
Gravity and magnetic data along a seismic refraction-reflection line in northwest Nevada and northeast California
No abstract available.
Authors
Janet E. Tilden, David A. Ponce, Jonathan M. G. Glen, Kathleen D. Gans
Hawaiian Volcano Observatory seismic data, January to December 2004
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 issued
Authors
Jennifer S. Nakata
Landslide hazards: A national threat
Landslides occur and can cause damage in all 50 States. Severe storms, earthquakes, volcanic activity, coastal wave attack, and wildfires can cause widespread slope instability. Landslide danger may be high even as emergency personnel are providing rescue and recovery services.
To address landslide hazards, several questions must be considered: Where and when will landslides occur? How big will
Authors
Late Pleistocene granodiorite source for recycled zircon and phenocrysts in rhyodacite lava at Crater Lake, Oregon
Rhyodacite tephra and three lavas erupted ∼27 ka, interpreted to be early leaks from the climactic magma chamber of Mount Mazama, contain ubiquitous resorbed crystals (antecrysts) that were recycled from young granodiorite and related plutonic rocks of the same magmatic system. The shallow composite pluton is represented by blocks ejected in the 7.7-ka climactic eruption that formed Crater Lake ca
Authors
C. R. Bacon, J. B. Lowenstern
Repeating coupled earthquakes at Shishaldin Volcano, Alaska
Since it last erupted in 1999, Shishaldin Volcano, Aleutian Islands, Alaska, has produced hundreds to thousands of long-period (1-2 Hz; LP) earthquakes every day with no other sign of volcanic unrest. In 2002, the earthquakes also exhibited a short-period (4-7 Hz; SP) signal occurring between 3 and 15 s before the LP phase. Although the SP phase contains higher frequencies than the LP phase, its s
Authors
J. Caplan-Auerbach, T. Petersen
Experimental and geochemical evidence for derivation of the El Capitan Granite, California, by partial melting of hydrous gabbroic lower crust
Partial melting of mafic intrusions recently emplaced into the lower crust can produce voluminous silicic magmas with isotopic ratios similar to their mafic sources. Low-temperature (825 and 850°C) partial melts synthesized at 700 MPa in biotite-hornblende gabbros from the central Sierra Nevada batholith (Sisson et al. in Contrib Mineral Petrol 148:635–661, 2005) have major-element and modeled tra
Authors
K. Ratajeski, T. W. Sisson, A. F. Glazner
Rainfall-induced landslides in Puerto Rico: An overview
Rainfall-induced landslides are common in Puerto Rico (PR). The presence of steep slopes in mountainous terrain, coupled with weathered soils and intense rainfall, leads to severe slope-stability problems throughout the island. Episodic triggering events such as hurricanes and earthquakes further exacerbate these problems. All physiographic provinces of the island have experienced landslides. The
Authors
M.A. Pando, M.E. Ruiz, M. C. Larsen
DUCKS: Low cost thermal monitoring units for near-vent deployment
During 1999 we designed and tested a thermal monitoring system to provide a cheap, robust, modular, real-time system capable of surviving the hostile conditions encountered proximal to active volcanic vents. In November 2000 the first system was deployed at Pu'u 'O'o (Kilauea, Hawai'i) to target persistently active vents. Aside from some minor problems, such as sensor damage due to tampering, this
Authors
A. Harris, D. Pirie, K. Horton, H. Garbeil, E. Pilger, H. Ramm, R. Hoblitt, C. Thornber, M. Ripepe, E. Marchetti, P. Poggi
An integrated view of the chemistry and mineralogy of martian soils
The mineralogical and elemental compositions of the martian soil are indicators of chemical and physical weathering processes. Using data from the Mars Exploration Rovers, we show that bright dust deposits on opposite sides of the planet are part of a global unit and not dominated by the composition of local rocks. Dark soil deposits at both sites have similar basaltic mineralogies, and could refl
Authors
A. S. Yen, Ralf Gellert, C. Schroder, R.V. Morris, J.F. Bell, A.T. Knudson, B. C. Clark, D. W. Ming, J.A. Crisp, R. E. Arvidson, D. Blaney, J. Brückner, P. R. Christensen, D.J. DesMarais, P.A. De Souza, T.E. Economou, A. Ghosh, B.C. Hahn, Kenneth E. Herkenhoff, L.A. Haskin, J.A. Hurowitz, B.L. Joliff, J. R. Johnson, G. Klingelhofer, M.B. Madsen, S. M. McLennan, H.Y. McSween, L. Richter, R. Rieder, D. Rodionov, Laurence A. Soderblom, S. W. Squyres, N.J. Tosca, A. Wang, M. Wyatt, J. Zipfel
Estimation of regional material yield from coastal landslides based on historical digital terrain modelling
High-resolution historical (1942) and recent (1994) digital terrain models were derived from aerial photographs along the Big Sur coastline in central California to measure the long-term volume of material that enters the nearshore environment. During the 52-year measurement time period, an average of 21 000 ?? 3100 m3 km-1 a-1 of material was eroded from nine study sections distributed along the
Authors
C.J. Hapke
Water alteration of rocks and soils on Mars at the Spirit rover site in Gusev crater
Gusev crater was selected as the landing site for the Spirit rover because of the possibility that it once held a lake. Thus one of the rover's tasks was to search for evidence of lake sediments. However, the plains at the landing site were found to be covered by a regolith composed of olivine-rich basaltic rock and wind-blown 'global' dust. The analyses of three rock interiors exposed by the rock
Authors
L.A. Haskin, A. Wang, B.L. Jolliff, H.Y. McSween, B. C. Clark, D.J. Des Marais, S. M. McLennan, N.J. Tosca, J.A. Hurowitz, J.D. Farmer, A. Yen, S. W. Squyres, R. E. Arvidson, G. Klingelhofer, C. Schroder, P.A. De Souza, D. W. Ming, Ralf Gellert, J. Zipfel, J. Brückner, J.F. Bell, Kenneth E. Herkenhoff, P. R. Christensen, S. Ruff, D. Blaney, S. Gorevan, N.A. Cabrol, L. Crumpler, J. Grant, L. Soderblom
The carbon dioxide cycle
The seasonal CO2 cycle on Mars refers to the exchange of carbon dioxide between dry ice in the seasonal polar caps and gaseous carbon dioxide in the atmosphere. This review focuses on breakthroughs in understanding the process involving seasonal carbon dioxide phase changes that have occurred as a result of observations by Mars Global Surveyor.
Authors
Philip B. James, Gary B. Hansen, Timothy N. Titus