Sea of methane sealed beneath Arctic permafrost could trigger climate feedback loop if it escapes

Deep beneath the permafrost that blankets a group of islands in the Arctic Ocean lurks a growing and migrating sea of methane, researchers have discovered.

The thick permafrost, or ground that remains frozen for at least two years, forms a tight seal that has so far prevented millions of cubic feet of methane from wafting out — but there’s no guarantee that the potent greenhouse gas won’t eventually escape, according to a study published Dec. 13 in the journal Frontiers in Earth Science.