According to a recent paper published by MBARI geologists and their colleagues, methane gas bubbling through seafloor sediments has created hundreds of low hills on the floor of the Arctic Ocean. These enigmatic features, which can grow up to 40 meters (130 feet) tall and several hundred meters across, have puzzled scientists ever since they were first discovered in the 1940s.
This conceptual drawing (not to scale) shows Paull's hypothesis that methane gas from deep hydrate deposits could push sediment up from below the ocean bottom to create a pingo-like feature. The gray lines in the background are from a seismic profile through one of these enigmatic features. (Image: Copyright 2007 MBARI)