Mediterranean Sea million years ago (mya) in less than two years by the Zanclean flood. Water poured in from the Atlantic Ocean through a newly breached gateway now called the Strait of Gibraltar at an estimated rate of about three orders of magnitude (one thousand times) larger than the current flow of the Amazon River. The Mediterranean Sea has an average depth of and the deepest recorded point is in the Calypso Deep in the Ionian Sea. The coastline extends for . A shallow submarine ridge (the Strait of Sicily) between the island of Sicily and the coast of Tunisia divides the
Geography of the North Sea In the north, it opens in a widening funnel shape to the Norwegian Sea, which lies in the very north-eastern part of the Atlantic. The International Hydrographic Organization defines the limits of the North Sea as follows: "On the Southwest." A line joining the Walde Lighthouse (France, 1°55'E) and Leathercoat Point (England, 51°10'N). "On the Northwest." From Dunnet Head (3°22'W) in Scotland to Tor Ness (58°47'N) in the Island of Hoy, thence through this island to the Kame of Hoy (58°55'N) on to Breck Ness on Mainland (58°58'N) through this island to Costa Head (3°14'W) and to Inga Ness (59'17'N)