Archive | 2021
Experimental simulations of mixed gas hydrates dissociation in response to temperature changes in Qilian Mountain permafrost, China
Abstract
Gas hydrates are ice-like crystalline solids consisting of water and gas (predominantly methane). The methane gas bound in hydrate structures and their worldwide occurrence make them interesting not only as a potential energy source but also as a possible climate-relevant factor. Estimations predict that a certain amount of atmospheric CH 4 may originate through dissociation of global gas hydrates, which may exacerbate global warming (Ruppel and Kessler, 2017). In turn, climate warming is not only directly affecting the hydrate distribution, but also perturbing the hydrate stability field, leading to the release of CH 4 from hydrate-bearing sediments. Gas hydrates, particularly those associated within or below shallow permafrost, are likely to be affected by the climate processes. For instance, gas hydrates in Qilian Mountain permafrost (QMP) are found below thin permafrost layers at a shallow depth of around 133~396 m. They might be vulnerable to dissociation due to global warming resulting in a possible higher CH 4 gas emission in this area. Considering the environmental effect, a proper understanding of hydrate dissociation behavior under specific conditions is important for the stability of natural gas hydrate deposits with respect to climate change.