The National Methane Hydrates R&D Program
MITAS 2009 Beaufort Sea Expedition
On September 26, 2009, the U.S. Naval Research Laboratory (NRL) – in collaboration with the U.S. Department of Energy’s National Energy Technology Laboratory (NETL), the Royal Netherlands Institute for Sea Research (NIOZ), and a team of 32 university and government scientists from the U.S., Netherlands, Belgium and Germany – completed a first of its kind expedition in the Beaufort Sea (Fossil Energy/NETL news release). The 12-day Methane in the Arctic Shelf/Slope (MITAS) expedition represents the first step in a more thorough evaluation of the distributions and concentrations of methane and methane hydrates in the Arctic permafrost and oceans. This expedition also contributed to the understanding of methane as a source of energy and its potential role in global climate cycles. The integrated and comprehensive data sets collected during the expedition contributes to the characterization of the geologic, oceanographic, and atmospheric systems of the Beaufort Shelf and Slope.
This expedition integrated expertise in coastal ocean geophysics, sediment geochemistry, dissolved and free methane fluxes through the water column and into the atmosphere, sediment and water column microbiology and biogeochemistry, and detailed characterization of the sub-seafloor geology to address the following research topics:
- Acquire and integrate seismic, heat flow, geochemical, and lithostratigraphic data for evaluation of deep sediment hydrate distributions.
- Estimate spatial variation and controls on the vertical methane diffusion as compared to variations in lithostratigraphy, geologic structures, water column temperatures, heat flow, seismic profiles, and water depth.
- Develop and calibrate models to evaluate sediment hydrate loading, hydrate destabilization through warming, and the fate of methane after destabilization.
- Determine and model the transport of methane from the sediment through the water column into the atmosphere.
- Study the control of total methane emissions by microbial methane consumption in the sediment and in the water column.
- Study the contribution of methane to the benthic and pelagic carbon cycling.
In preparing for the expedition, chief scientist Richard B. Coffin (NRL) and co-chief scientists Jens Greinert (NIOZ), Kelly Rose (NETL), and Warren Wood (NRL) worked with other members of the site selection team to identify and select specific areas of interest. The team spent nine months reviewing pre-existing geophysical (both MMS and USGS seismic data), well logs, published scientific studies and held discussions with regional experts to select three regions of interest: Hammerhead, Thetis Island and Halkett (Figure 1). Specific sample locations were decided on board through review of the 3.5 kHz seismic data (Figure 2).
Figure 1. Click on image to enlarge.
Figure 2. Click on image to enlarge.
During the expedition these regions were surveyed for nearshore to offshore (20 m to 2000 m water column depths) variations in the shallow sediment and water column methane source(s) and cycling and the subsequent flux to the atmosphere. Sediment sampling was conducted with piston and multi corers. Water column sampling was with a rosette equipped with a Conductivity, Temperature, and Density (CTD) sensor and Niskin bottles.