Abstract

In 2011 and 2012, measurements of acoustic backscatter from natural methane seeps were made in the northern Gulf of Mexico in water depths between 1000-2000 m. The measurementswere made using a calibrated 18 kHz echo sounder with an 11 degree beamwidth in order to estimate the depth-dependent target strength (TS). The TS data indicate a wide variation in the rate of gas seepage from the seafloor. Several of these seeps were revisited with a remotely operated vehicle in order to optically assess the bubble size distribution and to estimate the rate at which gas bubbles were exiting the seafloor. The optical data show bubble sizes between 1-10 mm radius, and similar rates of gas seepage ranging from a few bubbles per second to several tens of bubbles per second. Together, these data help to suggest the requirements for acoustically estimating gas flux from the seafloor over large regions.

Department

Center for Coastal and Ocean Mapping

Publication Date

6-2013

Volume

19

Journal Title

Proceedings of Meetings on Acoustics

Pages

1-5

Conference Date

June 2-7, 2013

Publisher Place

Montreal, Canada

Rights

© 2013 Acoustical Society of America

Publisher

Acoustical Society of America

Digital Object Identifier (DOI)

10.1121/1.4799132

Document Type

Conference Proceeding

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