Summary: | Establishing if past millennial-scale climate change affected the stability of marine methane hydrate is important for our understanding of climatic change and determining the fate of marine hydrates in a future warmer world. We show using three-dimensional seismic data offshore of Mauritania, that episodic, millennial-scale shifts of the base of the hydrate stability zone can be imaged below the ocean floor. Process modelling suggests the base of the hydrate stability zone should have shallowed and deepened in response to climate change over the last ~150,000 years. Specifically, there is seismic evidence for millennial-scale shifts during the Holocene (~11,700 years) at a temporal resolution that has previously been unrealised. This is the first evidence that millennial-scale climatic cycles caused hydrate formation and dissociation and that hydrate instability should be expected in a warming world.
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