Find in Library

<p>Assessments of future climate-warming-induced seafloor methane (<span class="inline-formula">CH₄</span>) release rarely include anaerobic oxidation of methane (AOM) within the sediments. Considering that more than 90&thinsp;% of the <span class="inline-formula">CH₄</span> produced in ocean sediments today is consumed by AOM, this may result in substantial overestimations of future seafloor <span class="inline-formula">CH₄</span> release. Here, we integrate a fully coupled AOM module with a numerical hydrate model to investigate under what conditions rapid release of <span class="inline-formula">CH₄</span> 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&thinsp;<span class="inline-formula">^∘</span>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 <span class="inline-formula">CH₄</span> 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.</p>