Bottom Topography of Atlantic Ocean

The bottom topography of the Atlantic Ocean is highly varied and complex, reflecting the ocean’s long geological history and the interactions of tectonic plates. Read here to learn more.

The Atlantic Ocean has played a crucial role in human history, serving as a major highway for exploration, trade, and migration. It was a key route for European exploration and colonization of the Americas during the Age of Discovery.

The Arctic Ocean lies to the north, and the Southern Ocean (sometimes considered a part of the Atlantic) surrounds Antarctica to the south.

The bottom topography is an important part of oceanography, which helps in understanding the origin of reliefs, features, and marine life in the ocean.

Atlantic Ocean

The Atlantic Ocean stretches over a vast area, making it the second-largest ocean after the Pacific Ocean. It extends from the Arctic Ocean in the north to the Southern Ocean in the south.

• The Atlantic Ocean is the second-largest of the world’s five oceans, covering approximately 41 million square miles (106 million square kilometers).
• It is located between the continents of North and South America to the west and Europe and Africa to the east.

The Atlantic Ocean is connected to several other bodies of water, including the Arctic Ocean via the Greenland Sea, the Mediterranean Sea via the Strait of Gibraltar, and the Caribbean Sea via the Yucatán Channel and the Windward Passage.

The Atlantic Ocean is known for its major ocean currents, including the Gulf Stream, North Atlantic Drift, and the Canary Current. These currents have significant impacts on regional climates and marine ecosystems.

The Atlantic Ocean is home to numerous islands, both large and small. Some well-known islands include the Azores, Canary Islands, Bermuda, Cape Verde Islands, and the Caribbean islands.

The Atlantic Ocean is known for the formation of hurricanes (also known as cyclones or typhoons in other parts of the world), particularly in tropical and subtropical regions. These powerful storms can have significant impacts on coastal areas.

Related Articles: South Atlantic anomaly; Atlantic Meridional Overturning Circulation (AMOC)

Bottom topography of the Atlantic Ocean

The Atlantic Ocean can be subdivided into several regions, including the North Atlantic, South Atlantic, and the equatorial region.

The North Atlantic is further divided into the North American and Eurasian basins.

The Atlantic Ocean floor is characterized by features such as mid-ocean ridges, ocean trenches, and seamounts. The Mid-Atlantic Ridge, which runs down the center of the Atlantic, is one of the longest mountain ranges on Earth.

Mid-Atlantic Ridge

The Mid-Atlantic Ridge is a prominent underwater mountain range that extends along the center of the Atlantic Ocean from the Arctic Ocean in the north to the Southern Ocean in the south.

• It marks a divergent plate boundary, where the Eurasian, North American, South American, African, and Antarctic Plates are moving away from each other.
• The Mid-Atlantic Ridge is characterized by rugged, volcanic peaks and deep rift valleys.
• The ridge is known as Dolphin Rise to the north and Challenger Rise to the south of the equator.
• It is known as Wyville Thompson Ridge between Iceland and Scotland.
• The ridge becomes quite extensive to the south of Greenland and Iceland and is called the Telegraphic Plateau because the first cables were laid down in this area.
• Azores Rise bifurcates from the mid-Atlantic Ridge to the south of 40°N latitude and ex­tends up to the Azores Islands.
• Other fracture zones are also well marked, Gibbs Fracture Zone (near 40°N), Atlantis Fracture Zone (near 30°N), Oceanographic Fracture Zone (32°N), Kane Fracture Zone (25°N), Vema Fracture Zone (10°N), Romancha Fracture Zone (near equator) etc.

Trenches and Basins

The Atlantic Ocean features several deep-sea trenches, which are formed at convergent plate boundaries where one tectonic plate is subducting beneath another.

• The Puerto Rico Trench, located north of Puerto Rico, is one of the deepest trenches in the Atlantic Ocean.
• South Sandwich trench is located in the South Atlantic Ocean, east of South America. It is a subduction zone where the South American Plate is descending beneath the Scotia Plate. The trench is associated with volcanic activity in the South Sandwich Islands.

Mid-Ocean Basins

The Atlantic Ocean is divided into several deep ocean basins, including the North Atlantic Basin, the South Atlantic Basin, and the Sargasso Sea. These basins vary in size and depth and are surrounded by the continents and the Mid-Atlantic Ridge.

• North Atlantic Basin: This is the northernmost part of the Atlantic Ocean, extending from the Arctic Ocean in the north to the Mid-Atlantic Ridge in the south. It includes the Labrador Sea, Greenland Sea, Norwegian Sea, and parts of the Barents Sea.
• South Atlantic Basin: This is the southern counterpart to the North Atlantic Basin, stretching from the southern tip of South America to the African continent. It includes the Argentine Basin, the Brazil Basin, and the Falkland Plateau.
• Bermuda-Azores-Canary Triangle: This triangular region in the North Atlantic Ocean includes the Bermuda Islands, the Azores Islands, and the Canary Islands. It is a geologically complex area with volcanic islands and seamounts.
• North Equatorial Basin: This basin is situated in the tropical North Atlantic Ocean, between the Caribbean Sea and the African coast. It is influenced by the North Equatorial Current and features warm waters.

Continental Shelves and Continental Slopes

The Atlantic Ocean has extensive continental shelves along its coastlines. These are shallow, submerged platforms that extend from the continents into the ocean. They are important for marine ecosystems and are often used for fishing and oil and gas exploration.

Beyond the continental shelves, the seafloor gradually slopes downward toward the deep ocean basins. This transition is known as the continental slope. It is a region of steep underwater cliffs and canyons.

Bottom topography of Atlantic Ocean: other features

Abyssal Plains

Abyssal plains are flat, sediment-covered regions of the deep ocean floor. They are found in the Atlantic Ocean’s deep basins, away from the continental margins. Abyssal plains are some of the flattest and most featureless areas on Earth’s surface.

Seamounts

Seamounts are underwater mountains that rise abruptly from the seafloor. The Atlantic Ocean contains numerous seamounts, some of which were formed by volcanic activity. Some seamounts may approach the ocean’s surface, creating a habitat for marine life.

Guyots

Guyots are flat-topped seamounts that were once above sea level but have since subsided. They are often found in the deeper parts of the Atlantic Ocean and provide insight into past sea-level changes.

Sargasso Sea

The Sargasso Sea is a unique region in the North Atlantic Ocean characterized by calm, clear waters and the presence of Sargassum seaweed. It is located within the North Atlantic Gyre and is a critical habitat for marine life.

Caribbean Sea

While not a basin within the Atlantic Ocean itself, the Caribbean Sea is an enclosed sea surrounded by the Caribbean islands and the eastern coasts of Central and South America. It is connected to the Atlantic Ocean through various straits and passages.

Rift Valleys

In addition to the Mid-Atlantic Ridge, there are several rift valleys and fracture zones that traverse the Atlantic Ocean floor. These are associated with tectonic plate movements and are marked by geological features like faults and ridges.

Ocean deeps

The number of deeps in the Atlantic Ocean is less than in the Pacific Ocean because of the absence of the effects of Tertiary orogenic movements along the Atlantic coasts.

A few examples are Nares Deep, Puerto Rico Deep, Hatteras Deep, Columbia Deep (south of Haiti), Valdivia Deep, Buchanan Deep, Moseley Deep, Vema Deep, etc.

Conclusion

The bottom topography of the Atlantic Ocean is continually evolving due to plate tectonics, erosion, sedimentation, and other geological processes.

It is a fascinating and dynamic part of the Earth’s surface, with significant implications for oceanography, geology, and marine biology.

Also read: Bottom topography of Pacific Ocean; Bottom topography of Indian Ocean

-Article by Swathi Satish