For more than 25 years, the U.S. Geological Survey Gas Hydrates Project has compiled and maintained an internal database of locations where the existence of gas hydrate has been confirmed or inferred in research studies. The existence of gas hydrate was considered confirmed when gas hydrate was recovered by researchers or videotaped from a vehicle (such as a submersible or remotely operated vehicle) near the sea floor. The existence of gas hydrate was considered inferred when seismic data, borehole logs, or ...

Geochemical analysis of carbonate rock samples collected from seep fields on the RB1903 and AT41 research expeditions in the U.S. Mid- and South Atlantic. Samples were collected as a fingerprint to past hydrocarbon seep activity, fluid source, and depositional environment.

Bottom simulating reflections (BSRs) are seismic features that are imaged in marine sediments using high-energy, impulsive seismic sources such as air guns or generator-injector guns. BSRs often cut across sediment stratigraphy and are interpreted as marking the deepest depth at which gas hydrate can exist. Gas hydrate is a naturally occurring and widely distributed frozen form of water and gas (usually methane) stable at low temperatures (up to about 25 degrees Celsius [°C]) and intermediate pressures ...

A discrete sample introduction module (DSIM) was developed and interfaced to a cavity ring-down spectrometer to enable measurements of methane and CO2 concentrations and 13C values with a commercially available cavity ring-down spectrometer (CRDS). The DSIM-CRDS system permits the analysis of limited volume (5 - 100-ml) samples ranging six orders-of-magnitude from 100% analyte to the lower limit of instrument detection (2 ppm). We demonstrate system performance for methane by comparing concentrations and ...

One goal of the Indian National Gas Hydrate Program's NGHP-02 expedition was to examine the geomechanical response of marine sediment to the extraction of methane from gas hydrate found offshore eastern India in the Bay of Bengal. Methane gas hydrate is a naturally occurring crystalline solid that sequesters methane in individual molecular cages in a lattice of water molecules. Methane gas hydrate is a potential energy resource, but whether extracting methane from gas hydrate in the marine subsurface is ...

One goal of the Indian National Gas Hydrate Program's NGHP-02 expedition was to examine the geomechanical response of marine sediment to the extraction of methane from gas hydrate found offshore eastern India in the Bay of Bengal. Methane gas hydrate is a naturally occurring crystalline solid that sequesters methane in individual molecular cages in a lattice of water molecules. Methane gas hydrate is a potential energy resource, but whether extracting methane from gas hydrate in the marine subsurface is ...

Fine-grained sediments, or “fines,” are nearly ubiquitous in natural sediments, even in the predominantly coarse-grained sediments that host gas hydrates. Fines within these sandy sediments can be mobilized and subsequently clog flow pathways while methane is being extracted from gas hydrate as an energy resource. Using two-dimensional (2D) micromodels to test the conditions in which clogging occurs provides insights for choosing production operation parameters that optimize methane recovery in the ...

One of the primary goals of South Korea’s second Ulleung Basin Gas Hydrate Expedition (UBGH2) was to examine the geotechnical properties of the marine sediment associated with methane gas hydrate occurrences found offshore of eastern Korea in the Ulleung Basin, East Sea. Methane gas hydrate is a naturally occurring crystalline solid that sequesters methane in individual molecular cages formed by a lattice of water molecules. During UBGH2, concentrated gas hydrate was found in two sedimentary environments ...

One goal of Korea’s Second Ulleung Basin Gas Hydrate Expedition, UBGH2, is to examine geotechnical properties of the marine sediment associated with methane gas hydrate occurrences found offshore eastern Korea in the Ulleung Basin, East Sea. Methane gas hydrate is a naturally occurring crystalline solid that sequesters methane in individual molecular cages formed by a lattice of water molecules. Offshore Korea, gas hydrate is found in thin, coarse-grained sediment layers that are interbedded with fine ...

One of the primary goals of South Korea’s second Ulleung Basin Gas Hydrate Expedition (UBGH2) was to examine the geotechnical properties of the marine sediment associated with methane gas hydrate occurrences found off the shore of eastern Korea in the Ulleung Basin, East Sea. Methane gas hydrate is a naturally occurring crystalline solid that sequesters methane in individual molecular cages formed by a lattice of water molecules. During UBGH2, concentrated gas hydrate was found in two sedimentary ...

This report consists of two-dimensional marine seismic reflection profile data from the northern Gulf of Mexico. These data were acquired in 1998 and 1999 with the Research Vessels Tommy Munro (M1-98-GM) and Gyre (G1-99-GM). The data are available in binary and GIF image formats. Binary data are in Society of Exploration Geologists (SEG) SEG-Y format and may be downloaded for further processing or display. Reference maps and GIF images of the profiles may be viewed with your Web browser.

Geochemical analysis of sediment core pore fluids collected from seep fields on the FK190612 research expedition in the north Pacific Ocean along the Cascadia margin in June 2019. Samples were collected to deconvolve the different processes impacting the fluid chemistry, including hydrate dissociation and clay mineral dehydration during the smectite-illite transformation that releases inter-layer water.

Carbonate lipid biomarkers (n-alkanes, fatty acids, and fatty alcohols/sterols) were determined in carbonate rocks collected on the FK190612 research expedition in the north Pacific Ocean along the Cascadia Margin on in June and July 2019.