Gas migration through Opouawe Bank at the Hikurangi margin offshore New Zealand.

Koch, Stephanie, Schröder, Henning, Haeckel, Matthias, Berndt, Christian, Bialas, Jörg, Papenberg, Cord, Klaeschen, Dirk and Plaza-Faverola, Andreia (2016) Gas migration through Opouawe Bank at the Hikurangi margin offshore New Zealand. Geo-Marine Letters, 36 (3). pp. 187-196. DOI 10.1007/s00367-016-0441-y.

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Supplementary data:

Abstract

This study presents 2D seismic reflection data, seismic velocity analysis, as well as geochemical and isotopic porewater compositions from Opouawe Bank on New Zealand’s Hikurangi subduction margin, providing evidence for essentially pure methane gas seepage. The combination of geochemical information and seismic reflection images is an effective way to investigate the nature of gas migration beneath the seafloor, and to distinguish between water advection and gas ascent. The maximum source depth of the methane that migrates to the seep sites on Opouawe Bank is 1,500–2,100 m below seafloor, generated by low-temperature degradation of organic matter via microbial CO2 reduction. Seismic velocity analysis enabled identifying a zone of gas accumulation underneath the base of gas hydrate stability (BGHS) below the bank. Besides structurally controlled gas migration along conduits, gas migration also takes place along dipping strata across the BGHS. Gas migration on Opouawe Bank is influenced by anticlinal focusing and by several focusing levels within the gas hydrate stability zone.

Document Type: Article
Funder compliance: info:eu-repo/grantAgreement/EC/FP7/317888
Additional Information: WOS:000376258800003
Keywords: gas seepage, biogenic methane, fluid flow, Hikurangi margin, seimic velocity analysis, gas hydrate, RV Sonne, SO214, NEMESYS
Research affiliation: OceanRep > GEOMAR > FB2 Marine Biogeochemistry > FB2-MG Marine Geosystems
OceanRep > GEOMAR > FB4 Dynamics of the Ocean Floor > FB4-GDY Marine Geodynamics
Kiel University
Refereed: Yes
Open Access Journal?: No
DOI etc.: 10.1007/s00367-016-0441-y
ISSN: 0276-0460
Related URLs:
Projects: NEMESYS
Expeditions/Models/Experiments:
Date Deposited: 23 Feb 2016 07:51
Last Modified: 04 May 2017 11:01
URI: http://oceanrep.geomar.de/id/eprint/31452

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