Methane hydrates and climate change the clathrate gun hypothesis

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					April 8, 2004

Methane hydrates and climate change: the clathrate gun hypothesis

Richard J. Behl
AAPG Distinguished Lecturer

Kevin G. Cannariato
University of Southern California
Ingrid L. Hendy
University of Michigan
James P. Kennett
University of California, Santa Barbara

What caused repeated, remarkably rapid, global warming events that occurred in less than
one human lifespan during the late Quaternary? A likely, but controversial, culprit is methane
hydrate (or clathrate), which makes up a vast reservoir of frozen methane in ocean
sediments. Destabilization of the reservoir through changes in sea-floor temperature and
pressure may release methane (a powerful greenhouse gas) into the ocean and atmosphere,
with dramatic climatic consequences. The Clathrate Gun Hypothesis proposes that the marine
methane hydrate reservoir was repeatedly reloaded and discharged as clathrates accumulated
during cold glacial intervals only to be dissociated when triggered by pulses of warmer
intermediate water impinging on the continental slopes. This mechanism could have greatly
amplified and accelerated global warming episodes. Could methane hydrates play a role in
present and future climatic change,as well? This presentation explores whether the present is
always the best key to the past, or whether these dramatic episodes in Earth's history were
unique in their sensitivity to certain triggers of climatic and environmental change.

Richard J. Behl graduated in 1978 with his B.A. in Chemistry with Earth Sciences Specialization
from the University of California, he then went on to receive his Ph.D. in Earth Sciences from
the University of California at Santa Cruz in 1992. Between 1978 and 1987 Richard worked as
a wellsite geologist for a number of companies. From 1992 to 1995 Richard was a Postdoctoral
Fellow at the University of California. From 1995 to1999 Richard was an Assistant Professor at
California State University. Presently Richard is an Associate Professor at California State

Richard has authored and co-authored 29 professional papers, 54 abstracts, and 1 book on
marine sedimentology and stratigraphy, diagenesis of silica- and organic carbon-rich
sediments, and paleoceanography. Richard has special interests in the sedimentary record and
diagenesis of the Neogene through Quaternary of the California Margin. Richard is involved
with AAPG, American Geophysical Union, GSA, International Association of Sedimentologists,
and the Society for Sedimentary Geology.