Initial rise of bubbles in cohesive sediments by a process of viscoelastic fracture
Algar, Christopher K.
Boudreau, Bernard P.
Barry, Mark A.
MetadataShow full item record
An understanding of the mechanics of bubble rise in sediments is essential because of the role of bubbles in releasing methane to the atmosphere and the formation and melting of gas hydrates. Past models to describe and predict the rise of other buoyant geological bodies through a surrounding solid (e.g., magmas and hydrofractures) appear not to be applicable to bubbles in soft sediments, and this paper presents a new model for gas bubble rise in soft, fine-grained, cohesive sediments. Bubbles in such sediments are essentially “dry” (little if any free water) and grow through a process of elastic expansion and fracture that can be described using the principles of linear elastic fracture mechanics, which assume the existence of a spectrum of flaws within the sediment fabric. By extending this theory, we predict that bubbles initially rise by preferential propagation of a fracture in a (sub) vertical direction. We present a criterion for initial bubble rise. Once rise is initiated, the speed of rise is controlled by the viscoelastic response of the sediments to stress. Using this new bubble rise model, we estimate rise velocities to be of the order of centimeters per second. We again show that capillary pressure plays no substantive role in controlling bubble growth or rise.
Author Posting. © American Geophysical Union, 2011. 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 116 (2011): B04207, doi:10.1029/2010JB008133.
Showing items related by title, author, creator and subject.
Observations of bubbles in natural seep flares at MC 118 and GC 600 using in situ quantitative imaging Wang, Binbin; Socolofsky, Scott; Breier, John A.; Seewald, Jeffrey S. (John Wiley & Sons, 2016-04-02)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 ...
The use of diagnostic imaging for identifying abnormal gas accumulations in cetaceans and pinnipeds Dennison, Sophie; Fahlman, Andreas; Moore, Michael J. (Frontiers Media, 2012-06-06)Recent dogma suggested that marine mammals are not at risk of decompression sickness due to a number of evolutionary adaptations. Several proposed adaptations exist. Lung compression and alveolar collapse that terminate ...
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 ...