Geography and extent of North America
North America occupies the northern portion of the landmass generally referred to as the New World, the Western hemisphere, the Americas, or simply America. North America’s only land connection is to South America at the narrow Isthmus of Panama. (Geopolitically, all of Panama—including the segment east of the Panama Canal in the isthmus—is often considered a part of North America alone.) According to some authorities, North America begins not at the Isthmus of Panama but at the Isthmus of Tehuantepec, Mexico with the intervening region called Central America (or Middle America if the Caribbean is included) and resting on the Caribbean Plate. Before the Central American isthmus was raised, the region had been underwater. The islands of the West Indies delineate a submerged former land bridge, which had connected North America and South America via Florida.
The continental coastline is long and irregular. The Gulf of Mexico is the largest body of water indenting the continent, followed by Hudson Bay. Others include the Gulf of Saint Lawrence and the Gulf of California.
There are numerous islands off the continent’s coasts: principally, the Arctic Archipelago, the Greater and Lesser Antilles, the Alexander Archipelago, and the Aleutian Islands. Greenland, a Danish self-governing island and the world’s largest, is on the same tectonic plate (the North American Plate) but is not considered to be part of the continent. Bermuda is not part of the Americas, but is an oceanic island formed on the fissure of the Mid-Atlantic Ridge. The nearest landmass to it is Cape Hatteras, North Carolina, and it is often thought of as part of North America, especially given its historical political and cultural ties to Virginia and other parts of the continent.