Now showing items 1-10 of 77
More than a century of bathymetric observations and present-day shallow sediment characterization in Belfast Bay, Maine, USA: implications for pockmark field longevity
Mechanisms and timescales responsible for pockmark formation and maintenance remain uncertain, especially in areas lacking extensive thermogenic fluid deposits (e.g., previously glaciated estuaries). This study characterizes ...
Extension in Mona Passage, Northeast Caribbean
(Elsevier B.V., 2010-07-15)
As shown by the recent Mw 7.0 Haiti earthquake, intra-arc deformation, which accompanies the subduction process, can present seismic and tsunami hazards to nearby islands. Spatially-limited diffuse tectonic deformation ...
NOAA/West Coast and Alaska Tsunami Warning Center response criteria
(Tsunami Society, 2009)
West Coast/Alaska Tsunami Warning Center (WCATWC) response criteria for earthquakes occurring in the Atlantic and Caribbean basins are presented. Initial warning center decisions are based on an earthquake’s location, ...
Current subsidence rates due to compaction of Holocene sediments in southern Louisiana
(American Geophysical Union, 2006-06-14)
Relative contributions of geologic and anthropogenic processes to subsidence of southern Louisiana are vigorously debated. Of these, shallow sediment compaction is often considered dominant, although this has never been ...
Estimating pore-space gas hydrate saturations from well log acoustic data
(American Geophysical Union, 2008-07-09)
Relating pore-space gas hydrate saturation to sonic velocity data is important for remotely estimating gas hydrate concentration in sediment. In the present study, sonic velocities of gas hydrate–bearing sands are modeled ...
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)
Glacial morphology and depositional sequences of the Antarctic continental shelf
(Geological Society of America, 1995-07)
We propose a simple model for the unusual depositional sequences and morphology of the Antarctic continental shelf. Our model considers the regional stratal geometry and the reversed morphology of the Antarctic continental ...
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 ...
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 ...