August 24, 2014
On July 12, 2013, during the Okeanos Explorer Northeast U.S. Canyons Expedition 2013, scientists and technicians using the Deep Discoverer remotely operated vehicle successfully located active methane seeps and chemosynthetic communities, thus ground truthing suspected bubble streams in the water column detected by Okeanos Explorer's multibeam sonar in 2012. Video courtesy of the NOAA Office of Ocean Exploration and Research.
More than 500 methane cold seeps have been discovered along the Atlantic Ocean margin of the United States, according to a study published in Nature Geoscience. The discovery of these gas seeps suggests that natural methane leakage from the seafloor is far more widespread than previously thought.
To identify the seeps, researchers from Mississippi State University, the U.S. Geological Survey, the NOAA Office of Ocean Exploration and Research (OER), and other institutions analyzed approximately 94,000 square kilometers (36,000 square miles) of 3D water column sonar data collected by NOAA Ship Okeanos Explorer to generate maps of the methane plumes. Data was collected between 2011 and 2013, in areas from Cape Hatteras, North Carolina, to Georges Bank, Maine. In 2013, the presence of the seeps was further verified with seafloor images taken by the remotely operated vehicles Deep Discoverer and Jason.
The implications of the release of this methane into the ocean and possibly into the atmosphere are not yet understood and will likely be investigated by follow-on research for years to come. Further investigation into this major discovery is needed to determine why the seeps occur and whether these processes may be happening in even more places scientists wouldn’t expect, setting the stage for future discoveries. The U.S. Atlantic margin is now understood to be a fertile research area for furthering global understanding of the potential impact of cold methane seeps on climate change.
This discovery represents a major contribution from OER to the broader scientific and management communities. OER's mission includes the systematic collection and rapid public dissemination of high-quality ocean exploration data to encourage scientific discovery. This effort also contributes to the President’s Open Data Initiative.
A co-author of the seep study was Brown University undergraduate, Mali’o Kodis, who worked on analysis of the Okeanos Explorer data while serving as a NOAA Hollings Scholar. Training the next generation of explorers by providing opportunities for students to actively contribute to ocean exploration science and research is also a fundamental part of the OER mission.
The study, Widespread methane leakage from the sea floor on the northern US Atlantic Margin , by A, Skarke, C. Ruppel, M. Kodis, D. Brothers, and E. Lobecker in Nature Geoscience, is available online.
Chemosynthetic Communities and Gas Hydrates at Cold Seeps South of Nantucket, Okeanos Explorer Northeast U.S. Canyons Expedition 2013
Discovery of a New Deep Chemosynthetic Community, Deepwater Canyons 2013: Pathways to the Abyss
NOAA Ship Okeanos Explorer Northeast and Mid-Atlantic Canyons Expedition 2012
NOAA Ship Okeanos Explorer Atlantic Canyons Undersea Mapping 2012 Expeditions