The U.S. Geological Survey’s Gas Hydrates Project

The Gas Hydrates Project at the U.S. Geological Survey (USGS) focuses on the study of methane hydrates 

in natural environments. The project is a collaboration between the USGS Energy Resources and the USGS 

Coastal and Marine Geology Programs and works closely with other U.S. Federal agencies, some State 

governments, outside research organizations, and international partners. The USGS studies the formation 

and distribution of gas hydrates in nature, the potential of hydrates as an energy resource, and the interaction 

between methane hydrates and the environment. The USGS Gas Hydrates Project carries out field programs 

and participates in drilling expeditions to study marine and terrestrial gas hydrates. USGS scientists also 

acquire new geophysical data and sample sediments, the water column, and the atmosphere in areas where 

gas hydrates occur. In addition, project personnel analyze datasets provided by partners and manage unique 

laboratories that supply state-of-the-art analytical capabilities to advance national and international priorities 

related to gas hydrates.

Figure 1. In 2010, the U.S. Geological Survey recovered white 

chunks of gas hydrate (methane ice) mixed with gray sediment a 

few feet below the sea floor in the Arctic Ocean at a water depth of 

approximately 8,000 feet.

Gas hydrate forms when water and gas combine under 

specific relatively high pressure and low temperature conditions 

to make an ice-like solid (fig. 1). Methane, a chemical compound 

made up of one carbon and four hydrogen atoms, is the main 

component of natural gas and the most common gas in natural 

hydrate. The methane that becomes trapped in gas hydrate 

usually originates when micro-organisms break down carbonrich organic material that is deposited in sediments. Methane 

migrating upward from conventional natural gas reservoirs can 

also be trapped in gas hydrate.

The conditions of pressure and temperature required for 

gas hydrate to form are mostly present offshore in sediments 

of marine continental margins and onshore within and 

beneath continuous permafrost (permanently frozen ground). 

As gas hydrate forms, the hydrate structure can concentrate 

methane by up to 180 times compared to its volume as a 

free gas at air temperature and Earth’s surface pressure 

conditions. This property means that methane hydrate 

represents a concentrated, shallowly buried form of 

natural gas that could be used as an energy resource 

or that could be perturbed by changing ocean or 

atmospheric conditions. 

Contemporary estimates of mobile carbon 

trapped in natural gas hydrates vary by a factor of 

10. In absolute amounts, global gas hydrate deposits 

are estimated to sequester 3–24.8 × 1015 cubic meters 

(106,000–876,000 trillion cubic feet or TCF) of methane 

(Boswell and Collett, 2011). For comparison, consumption of 

natural gas in the United States in 2016 exceeded 27.49 TCF 

according to the U.S. Energy Information Administration. 

Studies indicate that gas hydrates may prevent at least 10–15 

percent of the global carbon inventory from circulating in the 

ocean-atmosphere system (Ruppel and Kessler, 2017).

The challenges inherent in studying gas hydrates explain 

why these compounds are not better characterized. For example, 

gas hydrates often occupy only a small fraction of the available 

space between sediment grains and will break down (dissociate) 

rapidly once removed from their original pressure and 

temperature conditions.

Energy Resources

The USGS Gas Hydrates Project provides leadership and 

expertise for the United States and for international programs 

that investigate the potential of gas hydrates as an energy 

resource. Project scientists have led, advised, or participated in 

more than a dozen domestic and international drilling projects 

to investigate the characteristics of gas hydrates in deepwater 

marine or Arctic permafrost settings (fig. 2). The participation 

U.S. Department of the Interior

U.S. Geological Survey Printed on recycled paper

Fact Sheet 2017–3079

January 2018
of the USGS in the planning and execution of research projects 

on the Alaskan North Slope, in the Canadian Mackenzie Delta 

and the northern Gulf of Mexico, and offshore India, South 

Korea, and the northern Cascadia margins has contributed to 

substantial advances in understanding the geologic controls on 

gas hydrate distribution and the feasibility of extracting gas from 

these deposits.

The USGS uses a petroleum systems framework to evaluate 

sedimentary basins that may contain high-concentration gas 

hydrate deposits and often analyzes existing seismic and 

borehole logging data to infer where gas hydrate is concentrated 

(Collett and others, 2009). The USGS also collaborates with 

the U.S. Department of Energy and other Federal and State 

agencies, international partners, and private industry to plan 

drilling of research wells to recover samples of gas hydrates and 

to study gas production from hydrates. Such tests can improve 

information about the potential viability of gas hydrates as an 

economic source of natural gas.

Another important component of the USGS Gas Hydrates 

Project’s energy studies is formal quantitative resource 

assessment. In 2008, the USGS completed the first-ever 

assessment of methane that is recoverable from gas hydrates by 

using existing technology. The case study focused on permafrostassociated gas hydrates on the Alaskan North Slope (U.S. Alaska 

Gas Hydrate Assessment Team, 2013) and adopted methodology 

that can be extended to other gas hydrate provinces. The USGS 

also frequently provides scientific and technical expertise to 

advance onshore and offshore gas hydrate assessments carried 

out by Federal and international collaborators. 

Gas Hydrate and the Environment

The USGS Gas Hydrates Project is an international leader 

in examining the interaction of gas hydrate and the environment. 

A B

C

Figure 2. A, The drilling rig used to explore gas hydrates associated with onshore permafrost near Prudhoe Bay, 

Alaska, in 2007. B, U.S. Geological Survey scientists measuring the properties of sediment cores retrieved during a 

drilling expedition to investigate the energy resource potential of gas hydrates. C, During a 2008 coring expedition 

on the Vancouver margin, pore waters were extracted from sediments for later chemical analyses to determine the 

source of the methane. 
Warm oceanic or atmospheric temperatures may destabilize 

gas hydrate deposits, which may then release methane to 

surrounding sediments and possibly to the ocean or atmosphere 

(fig. 3). As a potent greenhouse gas, methane that reaches the 

atmosphere could enhance climate warming. In the oceans, 

most of the methane emitted at the sea floor from degrading gas 

hydrates or other sources dissolves in the overlying waters, and 

some of the methane is converted to carbon dioxide by bacteria. 

Very little of the methane reaches the atmosphere if it is emitted 

at water depths of more than several hundred feet (Ruppel and 

Kessler, 2017). There are two settings in which gas hydrate is 

most susceptible to breaking down as oceans warm: one is on 

upper continental slopes at water depths of 300–800 meters 

(approximately 1,000–2,600 feet) and the other is on continental 

shelves that ring the Arctic Ocean and are underlain by 

permafrost (approximate water depth as much as 100 meters 

or 330 feet).

The USGS has developed regional maps of subsea 

permafrost distribution, which largely determines where gas 

hydrate that might be susceptible to warming ocean waters 

persists beneath the United States segment of the Arctic Ocean 

continental shelf. The USGS has also carried out oceanographic 

expeditions to map the distribution of gas hydrates beneath 

the upper continental slope in this part of the Arctic Ocean, to 

measure methane flux to the atmosphere at high latitudes, and 

to determine the rate of bacterial consumption of methane in the 

water column. 

The USGS is also examining the susceptibility of gas 

hydrates to warming ocean waters on midlatitude upper 

continental slopes on the United States Atlantic margin, where 

the USGS played a role in discovering hundreds of previously 

unknown sea-floor methane seeps from 2012 to 2014 (Skarke 

and others, 2014). In cooperation with the U.S. Department of 

Energy, the National Oceanic and Atmospheric Administration, 

and other partners, the USGS is conducting oceanographic 

cruises to map the extent of gas hydrates; locate methane plumes 

in the water column; and obtain sea-floor samples for geological, 

geochemical, and biological analyses. In addition, scientists from 

the British Geological Survey and the USGS are collaborating to 

link the timing of methane emissions to climate change events. 

A

B

Figure 3. A, Methane seeping from the sea floor among deep-sea chemosynthetic mussels offshore Virginia at approximately 1,000 meters 

water depth (3,300 feet). Image acquired by the Global Explorer remotely operated vehicle managed by Oceaneering, Inc. B, Ice-like gas 

hydrates under capping rock encrusted with mussels on the sea floor of the northern Gulf of Mexico. Image taken by a remotely operated 

vehicle managed by the National Oceanic and Atmospheric Administration’s Ocean Exploration and Research program.

Sea-Floor Stability

Submarine slides are unlikely to be caused by processes 

directly related to the formation of gas hydrates or the 

migration of free gas, but the presence of hydrates or gas 

bubbles in sediments may precondition slopes for failure 

during earthquakes. USGS researchers were among the first to 

recognize the spatial association of gas hydrate and submarine 

slides (Kayen and Lee, 1991), which can lead to tsunami and 

disrupt sea-floor infrastructure (for example, pipelines). Marine 

surveys conducted by the USGS have provided dramatic images 

of submarine slide scarps on United States marine margins 

and revealed the underlying distributions of free gas and gas 

hydrates. The USGS Gas Hydrates Project also measures the 

mechanical properties of hydrate-bearing and gas-charged 

sediments in the laboratory to use in models of submarine slope 

failure. Laboratory scientists also focus on the volume changes 

that accompany the breakdown of gas hydrates, an important 

issue for understanding sea-floor subsidence near conventional 

wells that are drilled through hydrate-bearing sediments or near 

future wells designed to extract methane from gas hydrates.
Laboratory Programs

The USGS Gas Hydrates Project maintains unique 

laboratory and field instrumentation for analyses of hydratebearing sediments, organic carbon, and methane. A scanning 

electron microscope with low-temperature capability allows 

researchers to image the arrangement of individual hydrate 

crystals and sediment grains, as shown in figure 4A. The 

USGS also operates a laboratory with state-of-the-art tools 

for measuring the properties of hydrate-bearing specimens 

maintained at their original pressure throughout the process 

of recovery from their natural setting, subsequent storage, 

and analysis (fig. 4B). The resulting data, as well as benchtop 

tests of methane production from dissociating gas hydrates, 

help scientists determine reservoir properties and the energy 

potential of gas hydrates. The USGS has also developed 

special geochemical tools to study components of the carbon 

cycle. These tools measure the properties of organic carbon 

in water-column and sediment samples and allow scientists 

to continuously determine the concentrations of methane and 

carbon dioxide in surface waters and the atmosphere during 

shipboard surveys. 

A

B

Figure 4. A, Scanning electron microscope image of gas hydrate 

crystals in a sediment sample. The scale is 50 micrometers (μm) or 

approximately 0.002 inches. B. USGS scientists work with special 

instrumentation for measuring the reservoir properties of hydratebearing sediments that are held at high pressures. 

References Cited

Boswell, R., and Collett, T.S., 2011, Current perspectives on 

gas hydrate resources: Energy & Environmental Science, v. 

4, p. 1206–1215, [Also available at https://doi.org/10.1039/

C0EE00203H].

Collett, T.S., Johnson, A.H., Knapp, C.C., and Boswell, R., 

2009, Natural gas hydrates—A review, in Natural gas 

hydrates—Energy resource potential and associated geologic 

hazards, ed. Collett, T.S., Johnson, A.H., Knapp, C.C., and 

Boswell, R.: American Association of Petroleum Geologists 

Memoir 89, p. 146–219.

Kayen, R.E., and Lee, H.J., 1991, Pleistocene slope instability 

of gas hydrate-laden sediment on the Beaufort sea margin: 

Marine Geotechnology, v. 10, no. 1–2, p. 125–141.

Ruppel, C.D., and Kessler, J.D., 2017, The interaction of 

climate change and methane hydrates: Reviews of Geophysics, v. 55, no. 1, p. 126–168. [Also available at 

https://doi.org/10.1002/2016RG000534].

Skarke, A., Ruppel, C., Kodis, M., Brothers, D., and Lobecker, 

E., 2014, Widespread methane leakage from the sea floor on 

the northern US Atlantic margin, Nature Geoscience, v. 7, 

no. 9, p. 657–661. [Also available at https://doi.org/10.1038/

ngeo2232].

U.S. Geological Survey Alaska Gas Hydrate Assessment Team, 

2013, National Assessment of Oil and Gas Project—Geologic assessment of undiscovered gas hydrate resources on 

the North Slope, Alaska: U.S. Geological Survey Digital 

Data Series 69–CC, 100 p. [Also available at https://doi.

org/10.3133/ds69CC.]

By Carolyn Ruppel

The USGS Gas Hydrates Project is supported by the USGS 

Coastal and Marine Geology Program and the USGS Energy 

Resources Program.

Further Information:

Coastal and Marine Geology Program Coordinator

Energy Resources Program Coordinator

U.S. Geological Survey

12201 Sunrise Valley Drive

Reston, VA 20192 USA

Email: webmaster-marine@usgs.gov;

 gd-energyprogram@usgs.gov

• Overview of the U.S. Geological Survey’s Gas Hydrates 

Project:

https://woodshole.er.usgs.gov/project-pages/

hydrates/index.html

• U.S. Geological Survey’s Energy Resources Program gas 

hydrates site:

https://energy.usgs.gov/OilGas/UnconventionalOilGas/

GasHydrates.aspx

• Gas Hydrate in Nature, USGS Fact Sheet 3080: 

https://doi.org/10.3133/fs20173080

Any use of trade, firm, or product names is for descriptive purposes only and does not 

imply endorsement by the U.S. Government.

ISSN 2327-6916 (print)

ISSN 2327-6932 (online)

https://doi.org/10.3133/fs20173079