Migration of methane gas through the hydrate stability zone in a low-flux hydrate province

Abstract

Research Article| April 01, 2002 Migration of methane gas through the hydrate stability zone in a low-flux hydrate province Andrew R. Gorman; Andrew R. Gorman 1Department of Geology and Geophysics, University of Wyoming, Laramie, Wyoming 82071, USA Search for other works by this author on: GSW Google Scholar W. Steven Holbrook; W. Steven Holbrook 1Department of Geology and Geophysics, University of Wyoming, Laramie, Wyoming 82071, USA Search for other works by this author on: GSW Google Scholar Matthew J. Hornbach; Matthew J. Hornbach 1Department of Geology and Geophysics, University of Wyoming, Laramie, Wyoming 82071, USA Search for other works by this author on: GSW Google Scholar Kara L. Hackwith; Kara L. Hackwith 1Department of Geology and Geophysics, University of Wyoming, Laramie, Wyoming 82071, USA Search for other works by this author on: GSW Google Scholar Dan Lizarralde; Dan Lizarralde 2School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, Georgia 30332, USA Search for other works by this author on: GSW Google Scholar Ingo Pecher Ingo Pecher 3Institute for Geophysics, University of Texas, Austin, Texas 78759, USA Search for other works by this author on: GSW Google Scholar Geology (2002) 30 (4): 327–330. https://doi.org/10.1130/0091-7613(2002)030<0327:MOMGTT>2.0.CO;2 Article history received: 13 Aug 2001 rev-recd: 21 Nov 2001 accepted: 28 Nov 2001 first online: 02 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share MailTo Twitter LinkedIn Tools Icon Tools Get Permissions Search Site Citation Andrew R. Gorman, W. Steven Holbrook, Matthew J. Hornbach, Kara L. Hackwith, Dan Lizarralde, Ingo Pecher; Migration of methane gas through the hydrate stability zone in a low-flux hydrate province. Geology 2002;; 30 (4): 327–330. doi: https://doi.org/10.1130/0091-7613(2002)030<0327:MOMGTT>2.0.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract New high-resolution seismic data show clear evidence for upward injection of methane gas well into the hydrate stability zone at the stable, low-methane-flux Blake Ridge crest. This movement of gaseous methane, through a thermo-dynamic regime where it should be trapped as hydrate, suggests that dynamic migrations of gas play an important role in the interaction of subseafloor methane with the ocean. In the study area, none of the seismic amplitude anomalies that provide evidence for gas migration reaches the seafloor; instead they terminate at the base of a highly reflective, unfaulted capping layer. Seismic inversions of anomalous regions show (1) increased velocities beneath the hydrate stability zone, suggesting less gas, and (2) increased velocities within the hydrate stability zone associated with observed low-amplitude chimneys and bright spots, indicating increased hydrate concentrations. These observations and analyses indicate that methane migrates upward as free gas hundreds of meters into the hydrate stability zone before forming hydrate. The observations strongly imply that given appropriate permeable pathways, free gas can escape into the ocean. Even in a low-flux environment, the hydrate stability zone is not an impermeable barrier to free-gas migration. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.