Abstract:

This dataset includes geochemistry and hydrate dissolution rate measurements from the field samples and laboratory experiments. Field samples were collected from Barkley Canyon August 24, 2009 to May 18, 2010.

Suggested Citation:

Jeffrey Chanton. 2016. Porewater geochemical concentrations and dissolution rates of buried gas hydrates from Barkley Canyon (Cascadian Margin) (August 24, 2009 to May 18, 2010) and laboratory experiments. Distributed by: GRIIDC, Harte Research Institute, Texas A&M University–Corpus Christi. doi:10.7266/N7T43R48

Publications:

Wilson, R. M., Lapham, L. L., Riedel, M., Holmes, M. E., & Chanton, J. P. (2015). Observing methane hydrate dissolution rates under sediment cover. Marine Chemistry, 172, 12–22. doi:10.1016/j.marchem.2015.03.004

Dornhoffer, T., Waldbusser, G., & Meile, C. (2015). Modeling lugworm irrigation behavior effects on sediment nitrogen cycling. Mar. Ecol. Prog. Ser., 534, 121–134. doi:10.3354/meps11381

Purpose:

To elucidate the mechanisms that have been proposed to account for the apparent stability and high variability in dissolution rates observed for natural hydrate outcrops. Apparent stability may be explained if dissolution of hydrate from an exposed surface is approximately balanced by formation of additional hydrate from below as gas migrating upwards through the sediment enters the hydrate stability zone such that there is no net change in the size of the hydrate over time. In addition, natural hydrate outcrops may be ‘shielded’ by some kind of covering consisting of biofilms or sediment, which increases the thickness of the diffusive boundary layer thereby slowing hydrate dissolution.

Data Parameters and Units:

From left to right in the field data file, Field measurement: sample name, depth (cm), date (month/day/year), millimolar methane, millimolar dissolved inorganic carbon (DIC), methane flux in units of mM per cm2 per year, 13C stable isotopic composition of methane, 13C stable isotopic composition of DIC, chloride concentration (mM), sulfate concentration (mM), percentage of methane, ethane and propane Laboratory experiments: Experiment number (replicates 1-5), Time (hours), Methane concentration units (mM)

Individual Files: