Gas Hydrates- Submarine Slope Destabilization

Science Center Objects

USGS scientists have a long tradition of studying submarine slope failures and were among the first to note a spatial link between slope failures and gas hydrates/gas-charged sediments. USGS Gas Hydrates scientists support the USGS Hazards Mission area through field-based surveys that refine understanding of this association and through geotechnical studies that evaluate the response of sediments to dissociation of gas hydrate. In recent years, USGS Gas Hydrates Project scientists have studied the Cape Fear Slide, the Storegga Slide, and slides on the US Beaufort margin

multichannel seismic line showing slope failures on the US Beaufort Margin.

1977 USGS multichannel seismic line showing slope failures on the US Beaufort Margin.

For decades, it has been postulated that submarine slope failures are spatially linked to the presence of gas hydrates/gas-charged sediments and temporally linked to episodes of climate change. The evidence for these linkages remains anecdotal, and increasingly the causal relationship between gas hydrates and slope failures is being questioned. More likely, gas hydrates and/or associated gas charging play a role in pre-conditioning slopes for failure. When triggered by earthquakes, oversteepening of sediments, or other factors, slopes containing gas hydrates/gas may fail. Several types of studies are required to clarify the relationships among slope failures, gas hydrates, and climate change. One of the key needs is determining whether currently-observed charging of sediments with methane gas and/or hydrate leads or lags the timing of slope failures.

Swath bathymetric map of the Cape Fear submarine slide

Swath bathymetric map of the Cape Fear submarine slide, the largest slide on the US Atlantic coast. Data were collected on the R/V Atlantis in 2003.