Full‐depth scalings for isopycnal eddy mixing across continental slopes under upwelling‐favorable winds

Abstract. Assessments of future climate-warming-induced seafloor methane (CH4) release rarely include anaerobic oxidation of methane (AOM) within the sediments. Considering that more than 90 % of the CH4 produced in ocean sediments today is consumed by AOM, this may result in substantial overestimations of future seafloor CH4 release. Here, we integrate a fully coupled AOM module with a numerical hydrate model to investigate under what conditions rapid release of CH4 can bypass AOM and result in significant fluxes to the ocean and atmosphere. We run a number of different model simulations for different permeabilities and maximum AOM rates. In all simulations, a future climate warming scenario is simulated by imposing a linear seafloor temperature increase of 3 ∘C over the first 100 years. The results presented in this study should be seen as a first step towards understanding AOM dynamics in relation to climate change and hydrate dissociation. Although the model is somewhat poorly constrained, our results indicate that vertical CH4 migration through hydraulic fractures can result in low AOM efficiencies. Fracture flow is the predicted mode of methane transport under warming-induced dissociation of hydrates on upper continental slopes. Therefore, in a future climate warming scenario, AOM might not significantly reduce methane release from marine sediments.

Download Full-text

Maintaining Continental Slopes

Science ◽

10.1126/science.296.5568.613d ◽

2002 ◽

Vol 296 (5568) ◽

pp. 613d-613 ◽

Cited By ~ 1

Keyword(s):

Continental Slopes

Download Full-text

Associations of demersal fish with sponge grounds on the continental slopes of the northwest Atlantic

Marine Ecology Progress Series ◽

10.3354/meps10127 ◽

2013 ◽

Vol 477 ◽

pp. 217-230 ◽

Cited By ~ 33

Author(s):

E Kenchington ◽

D Power ◽

M Koen-Alonso

Keyword(s):

Demersal Fish ◽

Northwest Atlantic ◽

Continental Slopes

Download Full-text

Population genetics, phylogeography, and systematics of the thornyhead rockfishes (Sebastolobus) along the deep continental slopes of the North Pacific Ocean

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f00-095 ◽

2000 ◽

Vol 57 (8) ◽

pp. 1701-1717 ◽

Cited By ~ 14

Author(s):

Carol A Stepien ◽

Alison K Dillon ◽

Amy K Patterson

Keyword(s):

Pacific Ocean ◽

Phylogenetic Trees ◽

Sequence Data ◽

North Pacific Ocean ◽

Geographic Distance ◽

The North ◽

Continental Slopes ◽

Genetic Patterns ◽

Northern Pacific ◽

Shortspine Thornyhead

Population genetic, phylogeographic, and systematic relationships are elucidated among the three species comprising the thornyhead rockfish genus Sebastolobus (Teleostei: Scorpaenidae). Genetic variation among sampling sites representing their extensive ranges along the deep continental slopes of the northern Pacific Ocean is compared using sequence data from the left domain of the mtDNA control region. Comparisons are made among the shortspine thornyhead (S. alascanus) (from seven locations), the longspine thornyhead (S. altivelis) (from five sites), which are sympatric in the northeast, and the broadbanded thornyhead (S. macrochir) (a single site) from the northwest. Phylogenetic trees rooted to Sebastes show that S. macrochir is the sister taxon of S. alascanus and S. altivelis. Intraspecific genetic variability is appreciable, with most individuals having unique haplotypes. Gene flow is substantial among some locations and others diverged significantly. Genetic divergences among sampling sites for S. alascanus indicate an isolation by geographic distance pattern. Genetic divergences for S. altivelis are unrelated to the hypothesis of isolation by geographic distance and appear to be more consistent with the hypothesis of larval retention in currents and gyres. Differences in geographic genetic patterns between the species are attributed to life history differences in their relative mobilities as juveniles and adults.

Download Full-text

Upwelling of Particulate Matter on Continental Slopes

10.1002/essoar.10502726.1 ◽

2020 ◽

Author(s):

Jochen Kaempf

Keyword(s):

Particulate Matter ◽

Continental Slopes

Download Full-text

A Suggested Origin of Continental Slopes and of Submarine Canyons

Geological Magazine ◽

10.1017/s0016756800076597 ◽

1950 ◽

Vol 87 (2) ◽

pp. 102-104 ◽

Cited By ~ 2

Author(s):

K. O. Emery

Keyword(s):

Sea Level ◽

Shear Plane ◽

Continental Margins ◽

Submarine Canyons ◽

Continental Shelves ◽

Continental Slopes

AbstractThrusting along a shear plane at the continental margins may result in a temporary up-bulging of the margins above sea-level. During the time of exposure erosion by streams should have incised canyons which now, after isostatic readjustment of the margins, constitute the widely distributed submarine canyons. Known downwarped peneplains below the surface of continental shelves may have been developed on the bulged margins by long continued erosion. The margins may, thus, have served as- sources of some sediments now found on land and believed to have been derived from a seaward direction.

Download Full-text