Kerguelen Plateau

The Kerguelen Plateau is a huge underwater feature in the southern Indian Ocean.

It sits on the Antarctic Plate near Australia. This plateau is roughly the same size as the country of South Africa. Most of it stays deep under the ocean waves. However, a small part breaks the surface of the sea. These parts are the Kerguelen Islands and the Heard and McDonald Islands.

The plateau is one of the largest igneous provinces in the world. This means it is a very large area made of volcanic rock.

This massive structure was created by a Kerguelen hotspot. A hotspot is a place where heat from deep in the Earth causes magma to rise. This process began around 130 million years ago. As the hotspot worked, it built up layers of volcanic rock. This created many different parts of the plateau over time. For example, the Southern Kerguelen Plateau formed between 120 and 110 million years ago.

Later, the Central Kerguelen Plateau formed between 101 and 100 million years ago. The hotspot even created the long Ninety East Ridge. This ridge stretches from 82 to 37 million years ago.

Scientists have studied this area to learn about Earth's history. Dennis E. Hayes named the Elan Bank. This bank formed about 108 to 107 million years ago. Researchers found that parts of the plateau were once attached to India. These parts are made of continental lithosphere, which is the thick outer layer of a continent. As India moved north, these pieces were left behind. This turned areas like the Elan Bank into microcontinents. A microcontinent is a tiny piece of land that was once part of a larger continent.

Long ago, the Kerguelen Plateau was not under the sea. It was a microcontinent that sat above the water. It even had thick forests of trees. Scientists found fossil wood from Araucarian and Cypress trees. These trees are similar to plants found in Antarctica. The plateau had soil layers that contained charcoal. This charcoal came from wildfires caused by lightning or lava.

Eventually, the land sank below the waves. It became fully submerged about 20 million years ago.

Even though it is mostly underwater, the plateau is very important for sea life. It acts like a giant wall in the ocean. When ocean currents hit the plateau, they are pushed upward. This movement brings nutrient-rich water from the deep ocean to the surface. This water is full of food for many creatures. Because of this, many whales visit the area to eat. You can find sperm, minke, and humpback whales here during the summer.

The plateau helps keep these animals well-fed in the southern ocean.