Now showing items 1-10 of 68
Elastic wave speeds and moduli in polycrystalline ice Ih, sI methane hydrate, and sII methane-ethane hydrate
(American Geophysical Union, 2009-02-27)
We used ultrasonic pulse transmission to measure compressional, P, and shear, S, wave speeds in laboratory-formed polycrystalline ice Ih, sI methane hydrate, and sII methane-ethane hydrate. From the wave speed's linear ...
Correction to “Elastic wave speeds and moduli in polycrystalline ice Ih, sI methane hydrate, and sII methane-ethane hydrate”
(American Geophysical Union, 2009-04-10)
Duration and severity of Medieval drought in the Lake Tahoe Basin
(Elsevier B.V., 2001-09-16)
Droughts in the western U.S. in the past 200 years are small compared to several megadroughts that occurred during Medieval times. We reconstruct duration and magnitude of extreme droughts in the northern Sierra Nevada ...
Modeling sulfate reduction in methane hydrate-bearing continental margin sediments : does a sulfate-methane transition require anaerobic oxidation of methane?
(American Geophysical Union, 2011-07-12)
The sulfate-methane transition (SMT), a biogeochemical zone where sulfate and methane are metabolized, is commonly observed at shallow depths (1–30 mbsf) in methane-bearing marine sediments. Two processes consume sulfate ...
Gas and gas hydrate distribution around seafloor seeps in Mississippi Canyon, Northern Gulf of Mexico, using multi-resolution seismic imagery
(Elsevier B.V., 2008-05-10)
To determine the impact of seeps and focused flow on the occurrence of shallow gas hydrates, several seafloor mounds in the Atwater Valley lease area of the Gulf of Mexico were surveyed with a wide range of seismic ...
Plate interaction in the NE Caribbean subduction zone from continuous GPS observations
(American Geophysical Union, 2012-05-19)
Kinematic similarities between the Sumatra and Puerto Rico Trenches highlight the potential for a mega-earthquake along the Puerto Rico Trench and the generation of local and trans-Atlantic tsunamis. We used the horizontal ...
Assessing sulfate reduction and methane cycling in a high salinity pore water system in the northern Gulf of Mexico
(Elsevier B.V., 2008-05-10)
Pore waters extracted from 18 piston cores obtained on and near a salt-cored bathymetric high in Keathley Canyon lease block 151 in the northern Gulf of Mexico contain elevated concentrations of chloride (up to 838 mM) and ...
Vertical motions of the Puerto Rico Trench and Puerto Rico and their cause
(American Geophysical Union, 2005-06-22)
The Puerto Rico trench exhibits great water depth, an extremely low gravity anomaly, and a tilted carbonate platform between (reconstructed) elevations of +1300 m and −4000 m. I argue that these features are manifestations ...
A photographic and acoustic transect across two deep-water seafloor mounds, Mississippi Canyon, northern Gulf of Mexico
(Elsevier B.V., 2008-05-21)
In the northern Gulf of Mexico, a series of seafloor mounds lie along the floor of the Mississippi Canyon in Atwater Valley lease blocks 13 and 14. The mounds, one of which was drilled by the Chevron Joint Industry Project ...
Tsunami hazard along the U.S. Atlantic coast
(Elsevier B.V., 2009-03-28)
Assessment of natural hazards typically relies on analysis of past occurrences of similar disaster events. Assessment of tsunami hazard to the Atlantic coast of the Unites States poses a scientific challenge because of the ...