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Northern Cascadia Margin gas hydrates — Regional geophysical surveying, IODP drilling leg 311, and cabled observatory monitoring
This article reviews extensive geophysical survey data, ocean drilling results and long-term seafloor monitoring that constrain the distribution and concentration of gas hydrates within the accretionary prism of the northern Cascadia subduction margin, located offshore Vancouver Island in Canada. Seismic surveys and geologic studies conducted since the 1980s have mapped the bottom simulating refle
Alaska North Slope terrestrial gas hydrate systems: Insights from scientific drilling
A wealth of information has been accumulated regarding the occurrence of gas hydrates in nature, leading to significant advancements in our understanding of the geologic controls on their occurrence in both the terrestrial and marine settings of the Arctic. Gas hydrate accumulations discovered in the Alaska North Slope have been the focus of several important geoscience and production testing rese
A review of the exploration, discovery, and characterization of highly concentrated gas hydrate accumulations in coarse-grained reservoir systems along the Eastern Continental Margin of India
The analysis of 3-D seismic data has become one of the most powerful ways to identify sand-rich gas hydrate reservoir systems and to directly identify highly concentrated gas hydrate prospects. Scientific drilling programs have shown that the occurrence of highly concentrated gas hydrate accumulations in coarse-grained, sand-rich, reservoir systems has a significant impact on the physical properti
U.S. Atlantic margin gas hydrates
The minimum distribution of gas hydrates on the U.S. Atlantic margin is from offshore South Carolina northward to the longitude of Shallop Canyon on the southern New England margin. Few wells have logged or sampled the gas hydrate zone on this margin, meaning that the presence of gas hydrates is inferred primarily based on seismic data that reveal bottom simulating reflections, mostly at water dep
Calcium-Carbonate hardness of public water supplies in the conterminous United States
Geographic variations in the hardness of water seem to parallel the geographic variations in certain cardiovascular diseases (Anderson and others, 1969; Biorck and others, 1965; Schroeder, 1966). Winton and McCabe (1970) have provided a recent review of the problem. The map, presented here, showing calcium-carbonate hardness of municipal raw-water sources in the conterminous United States has been
Gas hydrates on Alaskan marine margins
Gas hydrate distributions on the marine margins of the U.S. state of Alaska are more poorly known than those on other U.S. margins, where bottom simulating reflections have been systematically mapped on marine seismic data to support modern, quantitative assessments of gas-in-place in gas hydrates. The extent of bottom simulating reflections in the U.S. Beaufort Sea has been known since the late 1
Vitrinite reflectance analysis
Vitrinite is a maceral group (a set of organic matter types with similar properties and appearance) derived from the remains of woody material from vascular plants and is composed of the thermally evolved products of lignin and cellulose. Vitrinite is the dominant component of humic coal and is found as a minor component dispersed into sedimentary rocks, especially mudrocks, the primary source roc
Dam removal and river restoration
The removal of dams from rivers has become a common and widespread practice in the United States and Europe. Although often initiated by factors like economics and safety, ecosystem restoration is often a desired benefit and outcome of dam removal. We describe the physical and ecological effects that the placement and removal of dams have on rivers. We then focus on the drivers of dam removal, pre
Total alkali-silica diagram
The total alkali-silica (TAS) diagram is a scatterplot of the chemical concentrations of silica oxide (SiO2) versus total alkali-sodium oxide (Na2O) plus potassium oxide (K2O) – in volcanic rocks.
Foreword: Wetland carbon and environmental management
No abstract available.