Carolyn Ruppel, PhD

Inset map shows red rectangle on Alaskan North Slope corresponding to larger map, where the location of the Hydrate Well is shown as a yellow circle.

USGS scientists Steve Phillips and Adrian Garcia document and process sediment cores during the hydrate drilling expedition in November 2022.

USGS geotechnical engineer Adrian Garcia on site, with the hydrates drilling rig (far right) and the core processing tent (over Adrian’s right shoulder) in the background as the Arctic sun sits low on the horizon over the tundra in November 2022.

Composite results from the Alaska marine margin monograph chapter, modified from the figure by C. Ruppel and P. Hart. Red, yellow, and green lines indicate locations of seismic data lacking gas hydrate features, possibly having bottom simulating reflections (BSRs) indicative of gas hydrates, and definitely hosting BSRs, respectively.

Gas hydrate (orange material) and gas bubbles near the seafloor in the northern Gulf of America. As the methane bubbles are emitted, a rind of gas hydrate immediately forms around some of them. If more bubbles continue to feed from below, gas hydrate forms.

USGS personnel on the deck of the R/V Hugh R.

Ice-like gas hydrates under capping rock encrusted with mussels on the sea floor of the northern Gulf of America.

 Scanning electron microscope image of gas hydrate crystals in a sediment sample. The scale is 50 micrometers (µm) or approximately 0.002 inches

Timeline of past drilling activities conducted by countries, private sector firms, government agencies, and academe that have helped to refine global gas hydrate estimates and possible future drilling and production testing

Schematic showing the general setting of seeps on the US Atlantic margin and related processes, such as gas hydrate degradation, groundwater seepage, leakage through fractured rocks, or emissions from the seafloor overlying salt diapirs. Pockmarks shown in white, and the nominal updip limit of gas hydrate stability is represented by the dashed black line.

Worldwide distribution of observed and inferred gas hydrates in marine and permafrost-associated settings that have been the subject of drilling programs. The color coding refers to the primary sediment type in each location and therefore designates the likely type of gas hydrate reservoir at each site.

The Instrumented Pressure Testing Chamber (IPTC). A device for measuring the physical properties of naturally-occurring, hydrate-bearing sediment at nearly in situ pressure conditions

Water molecules (1 red oxygen and 2 white hydrogens) form a pentagonal dodecahedron around a methane molecule (1 gray carbon and 4 green hydrogens). This represents 2 of the 8 parts of the typical Structure I gas hydrate molecule.

Researchers have postulated that seafloor collapse or sediment failure could occur when certain drilling and extraction activities are conducted in deepwater marine environments where gas hydrates exist in the shallow sediments.  This schematic diagram, modified from Ruppel, Boswell, and Jones (2008), shows a compilation of other researchers

The USGS Gas Hydrates Project integrates across USGS mission areas, programs, and regions. The stars indicate the locations of personnel involved in the Gas Hydrates Project. Within the US, much of the research focuses on the Gulf of America and Alaska, which represent marine and permafrost-associated settings for gas hydrates, respectively.

1977 USGS multichannel seismic line showing slope failures on the US Beaufort Margin, the location that Kayen and Lee (1991) analyzed in their initial paper on submarine slides and gas hydrates.