Cretaceous climate warming led to a significant methane release from the seafloor, indicating potential for similar destabilization of gas hydrates under modern global warming. A field campaign on the remote Ellef Ringnes Island, Canadian High Arctic, discovered an astounding number of methane seep mounds in Cretaceous age sediments.
Cretaceous climate warming led to a significant methane release from the seafloor, indicating potential for similar destabilization of gas hydrates under modern global warming. A field campaign on the remote Ellef Ringnes Island, Canadian High Arctic, discovered an astounding number of methane seep mounds in Cretaceous age sediments.
Seep mounds are carbonate deposits, often hosting unique fauna, which form at sites of methane leakage into the seafloor. Over 130 were found covering over 10,000 square kilometers of the Cretaceous sea floor. They occurred over a very short time interval immediately following onset of Cretaceous global warming, suggesting that the warming destabilized gas hydrates and released a large burb of methane. Given that methane has 20 times the impact of CO2 as a greenhouse gas, such a release could have accelerated global warming at that time. This discovery supports concerns of potential destabilization of modern methane hydrates.
Read more at Geological Society of America
Image: This is the first methane mound, Canadian High Arctic. (Credit Stephen Grasby and Geological Society of America Bulletin)
