LOMONOSOV RIDGE

major submarine ridge of the Arctic Ocean. The ridge is 1,100 miles (1,800 km) long. From Ellesmere Island on the continental shelf of North America, the ridge extends north to a point near the North Pole and then continues south to a point near the continental shelf of the New Siberian Islands. The ridge divides the Arctic Ocean into two major basins, and it influences water circulation, marine life, and ice movement. The ridge crest, which at its highest point is at a depth of 3,200 feet (975 m), rises 6,00011,000 feet (1,8003,400 m) from the basin floor. The basin on the Atlantic side is more than 13,000 feet (4,000 m) deep, whereas the adjacent basin is about 11,000 feet deep. An aseismic ridge (characterized by no associated earthquake activity), it is asymmetrical in shape and has gentle relief over its surface. At one time it was believed that the Lomonosov Ridge was a continuation of the mid-oceanic ridge, with an associated seismic belt. It has been shown, though, that the seismic belt lies 250 miles (400 km) toward the Barents Sea from the ridge. Thus, the Lomonosov Ridge is not a part of the mid-oceanic ridge system.