Abstract
When in the form of free gas in the water column, methane seeps emanating from the seabed are strong acoustic targets that are often detectable from surface vessels using echo sounders.In addition to detecting that a seep is present at some location, it is also desirable to characterize the nature of the seep in terms of its morphology and flux rates. Here, we examine how much we can learn about seeps in the deep (> 1000 m) northern Gulf of Mexico using narrow-band split-beam echo sounders operating at fixed frequencies (18 kHz and 38 kHz).Methane seeps in this region are deeper than the methane hydrate stability zone, implying that bubbles of free gas form hydrate rinds that allow them to rise further in the water column than they otherwise would. While this behavior may aid in the classification of gas types in the seep, it is possible that the presence of hydrate rinds may also change the acoustic response of the bubbles and thereby make flux rate estimates more challenging. These and other aspects of seep characterization will be discussed.
Department
Center for Coastal and Ocean Mapping
Publication Date
2012
Volume
17, Issue 1
Journal Title
Proceeding of Meetings on Acoustics (POMA)
Pages
1-8
Conference Date
July 2 - July 6, 2012
Publisher Place
Edinburgh, Scotland
Rights
© 2012 Acoustical Society of America
Publisher
Acoustical Society of America
Digital Object Identifier (DOI)
10.1121/1.4772948
Document Type
Conference Proceeding
Recommended Citation
T. C. Weber, K. Jerram, and L. Mayer, ‘Acoustic sensing of gas Seeps in the deep ocean with split-beam Echosounders’, Proceedings of Meetings on Acoustics (POMA), Vol.17, Issue 1.