Comparison of methane concentration and stable carbon isotope data for natural samples analyzed by discrete sample introduction module - cavity ring down spectroscopy (DSIM-CRDS) and traditional methods

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 13C results obtained by the DSIM and traditional methods for a variety of sample types, including low concentration (nanomolar) seawater and high concentration (> 90%) natural gas. The expansive concentration range...

Categories: Data; Tags: Geochemistry, Temperate Northern Atlantic, Temperate Northern Pacific, U.S. Geological Survey, USGS, All tags... biogeochemistry, carbon cycle, carbon cycling, carbon dioxide, carbon isotope analysis, cavity ring-down spectroscopy, eastern continental margin of India, environment, gas hydrate resources, geochemical data, geochemistry, geochemistry, isotope geochemistry, marine chemistry, methane, methane hydrate, northern Cascadia margin, northern US Atlantic margin, ocean characteristics, oceanography, oceans, sediment geochemistry, stable isotopes, Fewer tags

Global compilation of published gas hydrate-related bottom simulating reflections

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 (those that usually correspond to greater than 500 meters water depth). BSRs have been mapped in all the world’s oceans, in inland seas (such as the Black Sea), and in Lake Baikal in Russia. This data release consists...

Categories: Data; Types: Map Service, OGC WFS Layer, OGC WMS Layer, OGC WMS Service; Tags: Alaska, Amazonia, Antarctica, Arctic, Argentina, All tags... Atlantic, Barents Sea, Beaufort Sea, Beaufort Sea Continental Coast and Shelf, Black Sea, Brazil, CMHRP, Canada, Cascadia, Chile, China, Coastal and Marine Hazards and Resources Program, Colombia, Congo, Department of the Interior, Ecuador, Energy Resources, Falkland Islands (Islas Malvinas), GeoPackage, Geophysics, Greenland, Gulf of Mexico, India, Indonesia, Japan, Marine Geology, Mid Atlantic, New Zealand, Nigeria, Northern Gulf of Mexico, Norwegian-Greenland Sea, Pacific, Patagonia, Republic of Korea, Russia, Sea of Japan, Sea of Okhotsk, South Africa, South China Sea, Sumatra, Svalbard, Taiwan, Temperate Northern Atlantic, Temperate Northern Pacific, U.S. Geological Survey, USGS, United States, Uruguay, WHCMSC, Woods Hole Coastal and Marine Science Center, environment, gas hydrate resources, geoscientificInformation, marine geophysics, marine offshore, natural gas resources, oceans, sea-floor characteristics, seep, seismic reflection, seismic reflection methods, Fewer tags