Is the extent of glaciation limited by marine gas-hydrates

Journal Article · Fri Mar 01 04:00:00 EST 1991 · Geophysical Research Letters (American Geophysical Union); (United States)

DOI:https://doi.org/10.1029/91GL00351· OSTI ID:5518317

Paull, C K; Ussler, W III ^[1]; Dillon, W P ^[2]

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1. Univ. of North Carolina, Chapel Hill (United States)
2. Geological Survey, Woods Hole, MA (United States)

Methane may have been released to the atmosphere during the Quaternary from Arctic shelf gas-hydrates as a result of thermal decomposition caused by climatic warming and rising sea-level; this release of methane (a greenhouse gas) may represent a positive feedback on global warming. The authors consider the response to sea-level changes by the immense amount of gas-hydrate that exists in continental rise sediments, and suggest that the reverse situation may apply - that release of methane trapped in the deep-sea sediments as gas-hydrates may provide a negative feedback to advancing glaciation. Methane is likely to be released from deep-sea gas-hydrates as sea-level falls because methane gas-hydrates decompose with pressure decrease. Methane would be released to sediment pore space at shallow sub-bottom depths (100's of meters beneath the seafloor, commonly at water depths of 500 to 4,000 m) producing zones of markedly decreased sediment strength, leading to slumping and abrupt release of the gas. Methane is likely to be released to the atmosphere in spikes that become larger and more frequent as glaciation progresses. Because addition of methane to the atmosphere warms the planet, this process provides a negative feedback to glaciation, and could trigger deglaciation.

• OSTI ID: 5518317
• Journal Information: Geophysical Research Letters (American Geophysical Union); (United States), Journal Name: Geophysical Research Letters (American Geophysical Union); (United States) Vol. 18:3; ISSN 0094-8276; ISSN GPRLA
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
540110*
58 GEOSCIENCES
580000 -- Geosciences
ALKANES
ATMOSPHERIC CHEMISTRY
CENOZOIC ERA
CHEMICAL REACTIONS
CHEMISTRY
CLIMATIC CHANGE
DECOMPOSITION
EMISSION
GAS HYDRATES
GEOLOGIC AGES
GLACIERS
GREENHOUSE EFFECT
HEATING
HYDRATES
HYDROCARBONS
LEVELS
METHANE
ORGANIC COMPOUNDS
PALEOCLIMATOLOGY
PALEONTOLOGY
PRESSURE DEPENDENCE
QUATERNARY PERIOD
SEA LEVEL
VARIATIONS