Lake Erie is the second smallest of the five Great Lakes and shallowest. The Arctic Ocean is the smallest and shallowest of the world's five major oceans. The reef surface is the shallowest part of the reef. The Arctic basin is the shallowest ocean basin on Earth. The basin is shallowest towards the north and gets progressively deeper towards the south. Grass Lake is the shallowest lake on the Chain, with an average depth of . The depth of the shallowest lagoon, Lago de las Damas, is 8 feet. Pasture Lake is the shallowest lake at deep with a surface area of . Not surprisingly, the shallowest portions of subduction zones are known best. It is the shallowest lake of the chain. The eastern end is the shallowest where the River Yeo enters. The shallowest parts of the spurs support fire corals and zoanthids. The common duct, by far the shallowest of the five, is underground. The shallowest stops may be done breathing pure oxygen. The shallowest bulb will bloom first for three weeks, followed by the subsequent layers.