Centre for Deep Sea Research

A Hot and Deep Origin of Methane in Seafloor Hydrothermal Springs

Associate professor Eoghan Reeves at the K.G. Jebsen Centre for Deep Sea Research involved in a new study featured by the Deep Carbon Observatory.

Vent shrimp and gastropods
At Von Damm hydrothermal field, at the Mid-Cayman Spreading Center, hydrothermal vent shrimp and gastropods climb a chimney structure that releases methane-rich, super-heated 115 degree Celsius fluids into seawater
NOAA Okeanos Explorer Program, Mid-Cayman Rise Expedition 2011
Collecting fluids using a robotic arm
A robotic arm from a remotely operated vehicle collects fluid samples from a hydrothermal vent chimney at the Lost City site on the Mid-Atlantic Ridge.
Woods Hole Oceanographic Institution and Anna-Louise Reysenbach

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A new study featured by the Deep Carbon Observatory sheds further light on the origin of widespread methane venting in seafloor hot spring fluids. The investigation was developed by Associate Professor Eoghan Reeves  (Dept. of Earth Science and K.G. Jebsen Centre for Deep Sea Research), MIT/WHOI Joint Program graduate student David Wang and Professor Shuhei Ono of the Hardcore Stable Isotope Laboratory at MIT ). The researchers used novel measurements of methane clumped isotopologues (isotope 'flavors' of methane) to infer the temperature at which this critical carbon compound formed or was stored in the ocean crust. Methane is one of the "big three" chemicals nourishing chemosynthetic microorganisms in seafloor hot springs (hydrogen and hydrogen sulfide being the other two), says Reeves, but the only one whose origin has remained enigmatic. Reeves says this study is a critical step toward demonstrating a common origin of methane in fluids - most likely trapped bubbles of methane-rich gas in crustal rocks that are released by circulating fluids. The results were published this month in the journal Geochimica et Cosmochimica Acta