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.
Rapid ascent and emplacement of basaltic lava during the 2005–06 eruption of the East Pacific Rise at ca. 9°51′N as inferred from CO2 contents Gardner, James E.; Jackson, B. A.; Gonnermann, Helge; Soule, Samuel A. (2016-08)Eruption rates at the mid–ocean ridges (MORs) are believed to strongly control the morphology and length of lava flows emplaced along the ridge axis, and thus the structure and porosity of the upper oceanic crust. Eruption ...
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 ...
Dive, food and exercise effects on blood microparticles in Steller sea lions (Eumetopias jubatus) : exploring a biomarker for decompression sickness Fahlman, Andreas; Moore, Michael J.; Trites, Andrew W.; Rosen, David A. S.; Haulena, Martin; Waller, Nigel; Neale, Troy; Yang, Ming; Thom, Stephen R. (2016-02)Recent studies of stranded marine mammals indicate that exposure to underwater military sonar may induce pathophysiological responses consistent with decompression sickness (DCS). However, DCS has been difficult to ...