Written by James E. Kamis on 17DEC2014
This article was UPDATED on Dec 17, 2014 with new information on the Arctic's rift system and its likely affects on sea ice:
The floor of the Arctic Ocean is comprised of several significant geological features, most notably the giant Mid-Arctic Rift and associated Rift System. The system is 1100 miles long / 120 miles wide and topographically expressed as high mountains and Grand Canyon scale trenches.
In geological terms this is a major rift system, forming the boundary between two tectonic plates. Given its magnitude one would expect that it has been completely researched and is thoroughly understood. Quite the contrary scientists know very little about its geology due to its remote location, thick ice cover, and perceived geological inactivity. It is understandable that to date only limited amounts of data have been gathered concerning its heat flow and fluid expulsion.
However relatively new research has indicated that this giant rift system may not be so inactive after all. Given that overwhelming amounts of data now virtually prove selective melting of the Antarctic Ice Sheet is caused by geologically induced geothermal heat flow from the West Antarctic Rift System, it only seems reasonable to reevaluate the limited amount of data available on the Mid-Arctic Rift System.
The Mid-Arctic Rift System has long been considered geologically “inactive”, and presumed to be of little consequence relative to geothermal heat and fluid expulsion into the overlying Arctic Ocean. This assumption was primarily based on the Rift’s very slow “spreading rate”, 0.05 centimeters per year and its typically low seismicity.
Documentation and reinterpretation of this relatively recent research is as follows. First and most telling a recent 4.5 earthquake along the Gakkel Ridge Rift clearly shows that this large fault system is active. Although this was only a moderate size earthquake it was associated with a geographically extensive release of methane into the atmosphere as illustrated on the maps below from the Arctic News Blog (March 14, 2014).