An international research team has mapped the deepest methane seep ever recorded under Arctic sea ice, with plumes rising from sediment more than a kilometre below the surface.
The discovery was made during a 41-day expedition using an autonomous submarine. Over 300 sites were surveyed, and at least a dozen showed active venting.
Methane is a potent greenhouse gas, but researchers cautioned against alarm. Most of the gas dissolves in the water before reaching the atmosphere. The question is how much, and whether warming oceans will change the balance.
“This is not a headline about tipping points,” said the expedition’s chief scientist. “It is a map. And you cannot manage what you have not mapped.”
