Methane Hydrates Destabilized by Meltwater During Ice-Sheet Retreat, Study Finds
An international team of scientists has discovered that methane hydrates beneath the northwest Greenland continental shelf were rapidly destabilized by meltwater during ice-sheet retreat—a mechanism that contrasts sharply with previously assumed slow destabilization via temperature or pressure changes.
"Approximately 1,800 gigatons of methane is stored in hydrates beneath continental margins and permafrost."
The study, published in Nature Geoscience, analyzed sediment cores from IODP Expedition 400 and used 3D seismic imaging. Evidence indicates methane hydrates were locally dissolved and flushed out by large volumes of meltwater during the last glacial cycle.
Implications for Past and Future Climate
This mechanism may have contributed to past climate events, such as the Palaeocene-Eocene Thermal Maximum (PETM) ~56 million years ago. Ongoing ice sheet retreat could trigger future methane emissions via this process, potentially influencing the trajectory of climate change.