Gakkel Ridge(redirected from Nansen-Gakkel Ridge)
an underwater ridge in the Arctic Ocean between the abyssal Nansen and Amundsen depressions, the northern continuation of the Middle Atlantic Ridge. It is more than 1,000 km long and is composed of almost parallel ridges and numerous cone-shaped mountains of volcanic rocks (mainly basalts). Along the axis of the ridge there are deep canyons 20-30 km wide that form a rift valley. The summits of the ridge rise up to 4,000 m above the bottom of the ocean; the minimum known depth above the ridge is 400 m (the Lenin Komsomol Seamount). There is underwater volcanic and earthquake activity. The ridge was named in honor of its discoverer, Ia. Ia. Gakkel’.