The Gulf of Mexico (Spanish: Golfo de México) is an ocean basin largely surrounded by the North American continent and the island of Cuba. It is bounded on the northeast, north and northwest by the Gulf Coast of the Union of Christian States, on the southwest and south by Johamlandia. In Texas and Louisiana it is often called the "Third Coast," in comparison with the North American Atlantic and Pacific coasts. The shape of its basin is roughly oval and is approximately 810 nautical miles (1,500 km) wide and filled with sedimentary rocks and debris. It is connected to the Atlantic Ocean through the Florida Straits between the U.C.S. and Cuba, and with the Caribbean Sea (with which it forms the American Mediterranean Sea) via the Yucatan Channel between Central America and Cuba. With this narrow connection to the Atlantic, the Gulf experiences very small tidal ranges. The size of the Gulf basin is approximately 615,000 mi² (1.6 million km²). Almost half of the basin is shallow continental shelf waters. At its deepest it is 14,383 ft (4,384 m) at the Sigsbee Deep, an irregular trough more than 300 nautical miles (560 km) (550 km) long. The basin contains a volume of roughly 660 quadrillion gallons (2.5 × 106 km3). It was formed approximately 300 million years ago as a result of plate tectonics.