Methane Gas Hydrates: A Tale of Bubbles Great and Small
U.S. Geological Survey
Woods Hole Science Center
Methane gas hydrate is a naturally-occurring, solid form of water and methane gas that is stable at the elevated pressures and reduced temperatures characteristic of subsea or sub permafrost sediments. Methane gas hydrate has been found in Arctic permafrost sediment and in continental margin sediments the world around, and though global estimates of the amount of methane stored in hydrates vary greatly, there is general agreement that hydrate-bound methane constitutes a near-surface mobile carbon pool on par with all other fossil fuels combined. Methane, or natural gas, has captured widespread attention as both an energy resource and greenhouse gas, and that has driven much of the gas hydrate research over the past 30 years. More recently, as the hydrate community has been shifting from characterization studies to applied studies (centered in part on extracting methane from hydrate as a natural resource), there has been a greater drive to understand what happens to methane after it leaves the hydrate structure. Gas hydrate packs methane molecules together so efficiently that when a given volume of gas hydrate breaks down at room temperature, nearly 180 times that volume of methane is released. Bubbles are an almost inevitable consequence of such a breakdown and this seminar will provide a bubble’s eye view of the aftermath of gas hydrate breakdown in the sediment, in the water column and in the laboratory.
Bill Waite has spent the past 18 years being thrilled, confused, inspired and exasperated by gas hydrates—an educational relationship that began with an innocent post-doctoral position at Stanford before shifting to Stanford’s partner in gas hydrate crime, the U.S. Geological Survey in Menlo Park, California. Bill transferred to the USGS in Woods Hole, Massachusetts in 2000, and has moved from laboratory studies of physical properties of pure gas hydrates, to laboratory and field measurements of the physical properties of hydrate in sediment. Most recently, Bill has become an amateur bubble-ologist in a collaboration with Prof. Tom Weber at UNH and others looking at the fate of methane bubbles released from the seafloor.
Bill received his Ph.D. in physics from the University of Colorado in 1998 after majoring in physics at Oberlin College, Ohio.