Methane hydrate accumulation model for the central Nankai accretionary prism

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doi: 10.1016/j.margeo.2005.09.019
Author(s): He Lijuan; Matsubayashi, Osamu; Lei, Xinglin
Author Affiliation(s): Primary:
Chinese Academy of Sciences, Institute of Geology and Geophysics, Beijing, China
Other:
National Institute of Advanced Industrial Science and Technology, Japan
Volume Title: Marine Geology
Source: Marine Geology, 227(3-4), p.201-214. Publisher: Elsevier, Amsterdam, Netherlands. ISSN: 0025-3227 CODEN: MAGEA6
Note: In English. 36 refs.; illus., incl. 2 tables, sketch map
Summary: A two-dimensional transient model of methane hydrate accumulation is designed and applied in the Nankai accretionary prism. Model results show that the formation and distribution of methane hydrate and free gas is related to value of the thermal flux, the fluid flux, the methane flux supplied from below, and methane source within the sediment. The duration of the methane flux is of significant importance. The older the sediments, implying a longer period of methane flux supply from below and within the sediments of the model, the larger the volume percentage of free gas will be. This can explain the occurrence of BSR in a area with lower methane flux observed, but absence of the BSR in the other area with higher methane flux observed. Modeling also predicts that the maximum saturation of methane hydrate is about 1% of the pore space in the area of ODP Site 1178, and the methane hydrate occurrence zone is probably 90-200 m below the sea floor (mbsf), which is supported by both direct and indirect evidence for hydrate. In the area near ODP Site 808, the fault zones having high fluid flow and methane flux may possibly result in methane hydrate formation without BSR occurrence. Abstract Copyright (2006) Elsevier, B.V.
Year of Publication: 2006
Research Program: ODP Ocean Drilling Program
Key Words: 07 Marine Geology and Oceanography; Accretionary wedges; Aliphatic hydrocarbons; Alkanes; Asia; Bottom-simulating reflectors; Case studies; Continental slope; Far East; Gas hydrates; Gases; Geophysical methods; Heat flow; Hydrocarbons; Japan; Leg 190; Marine sediments; Methane; Nankai Trough; North Pacific; Northwest Pacific; ODP Site 1178; ODP Site 808; Ocean Drilling Program; Ocean floors; Organic compounds; Pacific Ocean; Sediments; Seismic methods; Shikoku; Theoretical models; Two-dimensional models; West Pacific
Coordinates: N322105 N322111 E1345646 E1345634
N324300 N324400 E1342900 E1342800
Record ID: 2006045080
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from CAPCAS, Elsevier Scientific Publishers, Amsterdam, Netherlands