2008 Annual Science Report
University of Hawaii, Manoa Reporting | JUL 2007 – JUN 2008
Serpentinazation and Abiogenic Methane in the Mariana Forearc
In the past year I have received funding from NSF, in addition to that from NASA-NAI, to look at this problem from a theoretical standpoint, in collaboration with Dr. Tom McCollom at the University of Colorado. Together we are modeling the processes that generate this extreme environment, including 1) dehydration and dissolution of subducted organic and inorganic carbon from the subducting oceanic plate with increasing temperature and pressure; 2) ascent of this water and dissolved carbon and its input into the ultramafic rock of the overriding plate; 3) serpentinization of this rock and accompanying generation of H2; 4) reaction of H2 with carbon to make methane that ultimately fuels extremophilic (high pH) microbial communities in the shallow subseafloor. This methane is abiogenic, so this process may be analogous to what may be happening on Mars.
PROJECT INVESTIGATORS:Michael Mottl