Atlantic Ocean

The Atlantic Ocean is the second largest of Earth's five oceanic divisions. It covers approximately 17% of the planet's surface. It also contains about 24% of the world's water surface area.

The ocean forms an elongated, S-shaped basin. It stretches between the Americas to the west and Europe and Africa to the east. This massive body of water is a vital part of the interconnected World Ocean. It connects to the Arctic Ocean in the north. It meets the Pacific Ocean in the southwest. It merges with the Indian Ocean in the southeast. It also connects to the Southern Ocean in the south.

The Atlantic is divided into two main sections by the Equator. These are the North Atlantic and the South Atlantic. The North Atlantic covers 41,490,000 square kilometers. This represents about 11.5% of the global ocean. The South Atlantic covers 40,270,000 square kilometers. This is about 11.1% of the global ocean.

Water temperatures vary greatly depending on location. The South Atlantic remains warm year-round because its basin countries are tropical. The North Atlantic has a temperate climate. This means it experiences seasons with both very high and very low temperatures. Surface temperatures can range from below -2°C to over 30°C.

Deep beneath the waves, the ocean floor is shaped by complex geology. The bathymetry, or the measurement of ocean depth, is dominated by the Mid-Atlantic Ridge (MAR). This is a massive submarine mountain range. It runs from 300 km south of the North Pole down to Bouvet Island. The MAR rises 2 to 3 km above the surrounding seafloor. It acts as a divergent boundary. This means the tectonic plates are moving apart at this location. In the North Atlantic, the North American and Eurasian plates move apart. In the South Atlantic, the South American and African plates move apart. This process creates basaltic volcanoes and pillow lava on the ocean floor.

The Mid-Atlantic Ridge is not a continuous wall. It is interrupted by large transform faults. These include the Romanche Trench near the Equator and the Gibbs fracture zone. These faults allow deep water currents to pass from one side of the ridge to the other. Some parts of the ridge rise above the water to form volcanic islands. These include Iceland, the Azores, and the Brazilian Atlantic Islands. Exploration of this ridge in the 1950s helped scientists accept the theories of seafloor spreading and plate tectonics.

In the 1870s, the Challenger expedition first discovered parts of this ridge. Later, the German Meteor expedition used echo-sounding in the 1920s to find more.

The Atlantic floor features many different landforms. There are wide continental shelves off Newfoundland and northeastern Europe. Most of the Atlantic is surrounded by passive margins. However, some areas have active margins that form deep trenches. The Puerto Rico Trench is the deepest point in the western Atlantic at 8,376 meters. The South Sandwich Trench is another deep point at 8,264 meters.

The ocean floor also contains abyssal plains, seamounts, and submarine canyons. In 1922, the USS Stewart used a Navy Sonic Depth Finder to map the bed. This device uses sonar, which sends sound pulses that bounce off the floor. This technology allowed for a continuous map with very little guesswork.

Human history has been deeply shaped by the Atlantic Ocean. Ancient Greek writers like Stesichorus and Herodotus mentioned it. They called it the "Sea of Atlas." They believed it was a great river surrounding all land. During the Age of Discovery, the ocean separated the "Old World" of Afro-Eurasia from the "New World" of the Americas. The Norse were the first known humans to cross it. However, Christopher Columbus's 1492 expedition was the most consequential. His voyage led to the exploration and colonization of the Americas by European powers like Spain, Portugal, France, and the United Kingdom.

This era included the Columbian exchange and the Atlantic slave trade.

Today, the Atlantic remains a central part of global systems. It is a core component of international trade. Major military conflicts have occurred here, such as the Cuban Missile Crisis and the Falklands War. Even in modern times, the ocean connects people. Some English speakers jokingly call it "the pond." This term dates back to 1640. It emphasizes the connection between Britain and its former colonies. Whether through trade or history, the Atlantic remains a bridge between continents.