BURNING ICE—WORLDWIDE OCCURRENCE OF GAS HYDRATE

Keith A. Kvenvolden

Photo of gas hydrate flame.

Natural gas hydrate is a solid substance composed of water and natural gas (mainly methane). Because methane is combustible, gas hydrate burns, when ignited, thus appearing to be burning ice. Natural gas hydrate occurs worldwide in oceanic sediments of outer continental margins and in sediments of polar regions. Three aspects of gas hydrates are important—their potential as a fossil fuel resource, their likely role as a submarine geohazard, and their possible effects on global climate change.

Photo of world map showing gas hydrate.

Because gas hydrate deposits contain a very large amount of methane, they are considered to be an unconventional, unproven source of that fossil fuel. The stability of gas hydrates is dependent on pressure and temperature, and changes in those parameters can destabilize the hydrates. Destabilized gas hydrate beneath the sea floor leads to geologic hazards such as submarine slumps and slides, examples of which are found worldwide. Destabilized gas hydrate may also affect climate through the release of methane, a “greenhouse” gas, which may enhance global climate change. USGS research in Menlo Park has addressed each of these three issues.

USGS interest in gas hydrate first crystallized in 1979 with a workshop in Menlo Park, dealing with gas hydrate in the National Petroleum Reserve in Alaska (summarized in USGS Open-file Report No. 81-1298). It was recognized that, although very little was known about in situ gas hydrate, what was known was of sufficient scientific interest to be worthy of further study. USGS Circular 825, published in 1980, reviewed the geologic occurrence of gas hydrates in oceanic and polar continental regions, setting the stage for the gas-hydrate research efforts in Menlo Park for the next two decades. Much of the new information about natural gas hydrate came about through cooperation between the USGS and the Deep Sea Drilling Program (later the Ocean Drilling Program). In the past five years, Menlo Park researchers have also undertaken fundamental studies of the physical properties of gas hydrate synthesized in the laboratory for comparison with naturally occurring gas hydrate.

Back to index