seas—and, in turn, the Black Sea, both of which also touch upon Asia) and Africa. In the southeast, the Atlantic merges into the Indian Ocean. The 20° East meridian, running south from Cape Agulhas to Antarctica defines its border. In the 1953 definition it extends south to Antarctica, while in later maps it is bounded at the 60° parallel by the Southern Ocean. The Atlantic has irregular coasts indented by numerous bays, gulfs and seas. These include the Baltic Sea, Black Sea, Caribbean Sea, Davis Strait, Denmark Strait, part of the Drake Passage, Gulf of Mexico, Labrador Sea, Mediterranean Sea, North Sea, Norwegian Sea, almost all of the Scotia Sea, and other tributary water bodies. Including these marginal seas the coast line of the Atlantic measures compared to for the Pacific. Including its marginal seas, the Atlantic covers an area of or 23.5% of the global ocean and has a volume of or 23.3% of the total volume of the earth's oceans. Excluding its marginal seas, the Atlantic covers and has a volume of . The North Atlantic covers (11.5%) and the South Atlantic (11.1%). The average depth is and the maximum depth, the Milwaukee Deep in the Puerto Rico Trench, is . Biggest seas in Atlantic Ocean Top large seas: Sargasso Sea - 3.5 million km2 Caribbean Sea - 2.754 million km2 Mediterranean Sea - 2.510 million km2 Gulf of Guinea - 2.35 million km2 Gulf of Mexico - 1.550 million km2 Norwegian Sea - 1.383 million km2 Hudson Bay - 1.23 million km2 Greenland Sea - 1.205 million km2 Argentine Sea - 1 million km2 Labrador Sea - 841,000 km2 Irminger Sea - 780,000 km2 Baffin Bay - 689,000 km2 North Sea - 575,000 km2 Black Sea - 436,000 km2 Baltic Sea - 377,000 km2 Libyan Sea - 350,000 km2 Levantine Sea - 320,000 km2 Celtic Sea - 300,000 km2 Tyrrhenian Sea - 275,000 km2 Gulf of Saint Lawrence - 226,000 km2 Bay of Biscay - 223,000 km2 Aegean Sea - 214,000 km2 Ionian Sea - 169,000 km2 Balearic Sea - 150,000 km2 Adriatic Sea - 138,000 km2 Gulf of Bothnia - 116,300 km2 Sea of Crete - 95,000 km2 Gulf of Maine - 93,000 km2 Ligurian Sea - 80,000 km2 English Channel - 75,000 km2 James Bay - 68,300 km2 Bothnian Sea - 66,000 km2 Gulf of Sidra - 57,000 km2 Sea of the Hebrides - 47,000