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Friday, October 16, 2015

Waters off Washington and Oregon releasing huge plumes of methane

Scientists have detected a disproportionate number of methane bubble plumes off the Washington and Oregon coast. The warming Pacific Ocean may be triggering the release of this powerful greenhouse gas, which has remained frozen beneath the seafloor for thousands of years.

The new study, which has been accepted for publication in Geochemistry, Geophysics, Geosystems, details over 160 bubble plumes observed over the past 10 years. An inordinate number of these plumes were observed at a critical depth where frozen methane "ice," or hydrate, decomposes on account of warmer ocean temperatures. Lead researcher H. Paul Johnson

from the University of Washington says these plumes are probably not coming from the seafloor sediments, but rather from decomposing frozen methane.

The downstream effects of the leaking methane aren’t entirely clear, though historically, methane has contributed to sudden and dramatic swings in the Earth’s climate. Once in the Earth’s atmosphere, methane acts as a powerful greenhouse gas. On a related note, warming-related methane emissions have also been detected in Arctic permafrost and off the Atlantic coast.

For more of the Gizmodo story: gizmodo.com