Observations of bubbles in natural seep flares at MC 118 and GC 600 using in situ quantitative imaging
Breier, John A.
Seewald, Jeffrey S.
MetadataShow full item record
This paper reports the results of quantitative imaging using a stereoscopic, high-speed camera system at two natural gas seep sites in the northern Gulf of Mexico during the Gulf Integrated Spill Research G07 cruise in July 2014. The cruise was conducted on the E/V Nautilus using the ROV Hercules for in situ observation of the seeps as surrogates for the behavior of hydrocarbon bubbles in subsea blowouts. The seeps originated between 890 and 1190 m depth in Mississippi Canyon block 118 and Green Canyon block 600. The imaging system provided qualitative assessment of bubble behavior (e.g., breakup and coalescence) and verified the formation of clathrate hydrate skins on all bubbles above 1.3 m altitude. Quantitative image analysis yielded the bubble size distributions, rise velocity, total gas flux, and void fraction, with most measurements conducted from the seafloor to an altitude of 200 m. Bubble size distributions fit well to lognormal distributions, with median bubble sizes between 3 and 4.5 mm. Measurements of rise velocity fluctuated between two ranges: fast-rising bubbles following helical-type trajectories and bubbles rising about 40% slower following a zig-zag pattern. Rise speed was uncorrelated with hydrate formation, and bubbles following both speeds were observed at both sites. Ship-mounted multibeam sonar provided the flare rise heights, which corresponded closely with the boundary of the hydrate stability zone for the measured gas compositions. The evolution of bubble size with height agreed well with mass transfer rates predicted by equations for dirty bubbles.
Author Posting. © American Geophysical Union, 2016. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research: Oceans 121 (2016): 2203–2230, doi:10.1002/2015JC011452.
Suggested CitationJournal of Geophysical Research: Oceans 121 (2016): 2203–2230
Showing items related by title, author, creator and subject.
Using carbon isotope fractionation to constrain the extent of methane dissolution into the water column surrounding a natural hydrocarbon gas seep in the northern Gulf of Mexico Leonte, Mihai; Wang, Binbin; Socolofsky, Scott A.; Mau, Susan; Breier, John A.; Kessler, John D. (American Geophysical Union, 2018-10-20)A gas bubble seep located in the northern Gulf of Mexico was investigated over several days to determine whether changes in the stable carbon isotopic ratio of methane can be used as a tracer for methane dissolution through ...
Stanley, Rachel H. R.; Jenkins, William J.; Lott, Dempsey E.; Doney, Scott C. (American Geophysical Union, 2009-11-19)Air-sea gas exchange is an important part of the biogeochemical cycles of many climatically and biologically relevant gases including CO2, O2, dimethyl sulfide and CH4. Here we use a three year observational time series ...
Dennison, Sophie; Moore, Michael J.; Fahlman, Andreas; Moore, Kathleen M. T.; Sharp, Sarah M.; Harry, Charles T.; Hoppe, Jane M.; Niemeyer, Misty E.; Lentell, Betty J.; Wells, Randall S. (The Royal Society, 2011-10-12)Bubbles in supersaturated tissues and blood occur in beaked whales stranded near sonar exercises, and post-mortem in dolphins bycaught at depth and then hauled to the surface. To evaluate live dolphins for bubbles, liver, ...