A conduit dilation model of methane venting from lake sediments
Scandella, Benjamin P.
Hemond, Harold F.
Ruppel, Carolyn D.
MetadataShow full item record
KeywordGreenhouse gas; Methane flux; Freshwater methane; Gas conduits; Effective stress; Ebullition
Methane is a potent greenhouse gas, but its effects on Earth's climate remain poorly constrained, in part due to uncertainties in global methane fluxes to the atmosphere. An important source of atmospheric methane is the methane generated in organic-rich sediments underlying surface water bodies, including lakes, wetlands, and the ocean. The fraction of the methane that reaches the atmosphere depends critically on the mode and spatiotemporal characteristics of free-gas venting from the underlying sediments. Here we propose that methane transport in lake sediments is controlled by dynamic conduits, which dilate and release gas as the falling hydrostatic pressure reduces the effective stress below the tensile strength of the sediments. We test our model against a four-month record of hydrostatic load and methane flux in Upper Mystic Lake, Mass., USA, and show that it captures the complex episodicity of methane ebullition. Our quantitative conceptualization opens the door to integrated modeling of methane transport to constrain global methane release from lakes and other shallow-water, organic-rich sediment systems, and to assess its climate feedbacks.
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 Geophysical Research Letters 38 (2011): L06408, doi:10.1029/2011GL046768.
Suggested CitationGeophysical Research Letters 38 (2011): L06408
Showing items related by title, author, creator and subject.
Holmes-Cerfon, Miranda C.; Whitehead, John A. (2010-10-23)Previous works have shown that when liquid flows in a pipe whose boundary temperature is below freezing, a tubular drainage conduit forms surrounded by solidified material that freezes shut under the appropriate combination ...
Mitchell, Samuel J.; Houghton, Bruce; Carey, Rebecca; Manga, Michael; Fauria, Kristen; Jones, Meghan R.; Soule, S. Adam; Conway, Chris E.; Wei, Zihan; Giachetti, Thomas (Springer, 2019-06-29)Meter-scale vesicular blocks, termed “giant pumice,” are characteristic primary products of many subaqueous silicic eruptions. The size of giant pumices allows us to describe meter-scale variations in textures and geochemistry ...
Semper, Stefanie; Pickart, Robert S.; Våge, Kjetil; Larsen, Karin Margretha H.; Hátún, Hjálmar; Hansen, Bogi (Nature Research, 2020-10-23)Dense water from the Nordic Seas passes through the Faroe Bank Channel and supplies the lower limb of the Atlantic Meridional Overturning Circulation, a critical component of the climate system. Yet, the upstream pathways ...