Pore size controls on the base of the methane hydrate stability zone in the Kumano Basin, offshore Japan

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doi: 10.1002/2014GL062135
Author(s): Daigle, Hugh; Dugan, Brandon
Author Affiliation(s): Primary:
University of Texas at Austin, Department of Petroleum and Geosystems Engineering, Austin, TX, United States
Rice University, United States
Volume Title: Geophysical Research Letters
Source: Geophysical Research Letters, 41(22), p.8021-8028. Publisher: American Geophysical Union, Washington, DC, United States. ISSN: 0094-8276 CODEN: GPRLAJ
Note: In English. 38 refs.; illus., incl. sketch map
Summary: The base of the methane hydrate stability zone (MHSZ) in the Kumano Basin, offshore Japan, is marked by a bottom-simulating reflection (BSR) on seismic data. At Integrated Ocean Drilling Program Site C0002, which penetrates this BSR, the in situ temperature profile combined with bulk seawater methane equilibrium conditions suggest that the base of the MHSZ is 428 m below seafloor (bsf), which is 28 m deeper than the observed BSR (400 m bsf). We found that submicron pore sizes determined by mercury injection capillary pressure are sufficiently small to cause 64% of the observed uplift of the base of the MHSZ by the Gibbs-Thomson effect. This is the most thorough characterization of pore sizes within the MHSZ performed to date and illustrates the extent to which pore size can influence MHSZ thickness. Our results demonstrate the importance of considering lithology and pore structure when assessing methane hydrate stability conditions in marine sediments. Abstract Copyright (2014), American Geophysical Union. All Rights Reserved.
Year of Publication: 2014
Research Program: IODP Integrated Ocean Drilling Program
Key Words: 07 Marine Geology and Oceanography; 20 Geophysics, Applied; Aliphatic hydrocarbons; Alkanes; Cores; Gas hydrates; Geophysical methods; Geophysical surveys; Hydrocarbons; IODP Site C0002; Integrated Ocean Drilling Program; Kumano Basin; Marine sediments; Methane; NanTroSEIZE; North Pacific; Northwest Pacific; Organic compounds; Pacific Ocean; Reflection methods; Sediments; Seismic methods; Surveys; West Pacific
Coordinates: N331800 N331801 E1363801 E1363800
Record ID: 2015041546
Copyright Information: GeoRef, Copyright 2017 American Geosciences Institute. Reference includes data from John Wiley & Sons, Chichester, United Kingdom