Observed correlation between the depth to base and top of gas hydrate occurrence from review of global drilling data

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doi: 10.1002/2017GC006805
Author(s): Riedel, M.; Collett, T. S.
Author Affiliation(s): Primary:
GEOMAR-Helmholtz Centre for Ocean Research Kiel, Kiel, Germany
U. S. Geological Survey, United States
Volume Title: Geochemistry, Geophysics, Geosystems - G<sup>3</sup>
Source: Geochemistry, Geophysics, Geosystems - G>3`, 18(7), p.2543-2561. Publisher: American Geophysical Union and The Geochemical Society, United States. ISSN: 1525-2027
Note: In English. 66 refs.; illus., incl. 1 table, sketch map
Summary: A global inventory of data from gas hydrate drilling expeditions is used to develop relationships between the base of structure I gas hydrate stability, top of gas hydrate occurrence, sulfate-methane transition depth, pressure (water depth), and geothermal gradients. The motivation of this study is to provide first-order estimates of the top of gas hydrate occurrence and associated thickness of the gas hydrate occurrence zone for climate-change scenarios, global carbon budget analyses, or gas hydrate resource assessments. Results from publically available drilling campaigns (21 expeditions and 52 drill sites) off Cascadia, Blake Ridge, India, Korea, South China Sea, Japan, Chile, Peru, Costa Rica, Gulf of Mexico, and Borneo reveal a first-order linear relationship between the depth to the top and base of gas hydrate occurrence. The reason for these nearly linear relationships is believed to be the strong pressure and temperature dependence of methane solubility in the absence of large difference in thermal gradients between the various sites assessed. In addition, a statistically robust relationship was defined between the thickness of the gas hydrate occurrence zone and the base of gas hydrate stability (in meters below seafloor). The relationship developed is able to predict the depth of the top of gas hydrate occurrence zone using observed depths of the base of gas hydrate stability within less than 50 m at most locations examined in this study. No clear correlation of the depth to the top and base of gas hydrate occurrences with geothermal gradient and sulfate-methane transition depth was identified. Abstract Copyright (2017), . American Geophysical Union. All Rights Reserved.
Year of Publication: 2017
Research Program: DSDP Deep Sea Drilling Project
IODP Integrated Ocean Drilling Program
IPOD International Phase of Ocean Drilling
ODP Ocean Drilling Program
Key Words: 07 Marine Geology and Oceanography; 29 Economic Geology, Energy Sources; Asia; Atlantic Ocean; Blake-Bahama Outer Ridge; Borneo; Cascadia Basin; Central America; Chile; Correlation; Costa Rica; Deep Sea Drilling Project; Depth; Drilling; East Pacific; Equatorial Pacific; Far East; Gas hydrates; Geothermal gradient; Global; Gulf of Mexico; Heat flow; IODP Site X314; IODP Site X353; IPOD; India; Indian Peninsula; Japan; Korea; Leg 112; Leg 131; Leg 141; Leg 146; Leg 164; Leg 170; Leg 201; Leg 204; Leg 76; Malay Archipelago; Nankai Trough; North Atlantic; North Pacific; Northeast Pacific; Northwest Atlantic; Northwest Pacific; Occurrence; Ocean Drilling Program; Ocean floors; Offshore; Pacific Ocean; Petroleum; Petroleum exploration; South America; South China Sea; South Pacific; Southeast Pacific; Stability; Statistical analysis; West Pacific
Record ID: 2017087512
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from John Wiley & Sons, Chichester, United Kingdom, Reference includes data supplied by, and/or abstract, Copyright, American Geophysical Union

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