Arctic mounds have gassy past

Monterey Bay Aquarium Research Institute (MBARI) scientists working in the Arctic Ocean unraveled the geological origin of many mysterious mounds, called "pingos", off Canada's north coast. Pingos are small, dome-shaped, ice-cored hills about 40m tall, found along the coast of the Tuktoyaktuk Peninsula. "Pingo-like features" are submerged along the continental shelf. Earlier studies claimed these features were formed on land, and then submerged when sea level rose following the end of the last ice age, over 10,000 years ago. Apparently, the reverse may be true. The terrestrial features may have been formed by methane gas bubbling up through the seafloor.

The work is important because the features are widespread on the Arctic margin, and they may be indicative of methane hydrate deposits. Methane hydrate is a potential new energy resource. Mounds in any region are also important to sea creatures, because topographic relief aggregates fish and invertebrates, increases mixing, and accelerates flows.

MBARI geologists Charlie Paull and William Ussler and their coauthors described the results of their investigation in the January issue of Geophysical Research Letters. Read more details, with more pictures, and the MBARI website here.

Image: (c) 2007 MBARI