Kerguelen Plateau

A big land sits deep under the sea.

It is near Australia. It is very large. Some small islands stay above the water.

These islands were once part of a bigger land. Long ago, the land was above the waves. It even had trees and forests. Now, the land is under the sea. Many whales swim here to find food.

They come to this spot to eat. It is a busy place in the ocean.

A massive land sits deep under the southern Indian Ocean.

This is the Kerguelen Plateau. It is near Australia. It is about the size of South Africa. Most of it stays below the sea.

Some small parts break the surface. These are the Kerguelen Islands and the Heard and McDonald Islands.

This plateau formed from a hotspot. A hotspot is a place where heat from deep inside the Earth makes magma rise. This started about 130 million years ago. Long ago, much of this land was above the waves. It was a microcontinent, which is a tiny piece of land. It even had forests with trees like cypresses.

Over time, the land sank. It became submerged about 20 million years ago.

Today, the plateau helps sea life. Ocean currents hit the plateau and move deep water up. This water is full of nutrients, which is food for many things. Because of this, many whales swim here to eat. You can find sperm whales and humpback whales in these waters.

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.

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

It is classified as a large igneous province, which is a very large area of volcanic rock. This plateau sits on the Antarctic Plate and is roughly the size of South Africa. Most of the plateau lies in deep water, far below the ocean surface. However, a small portion breaks the surface to form islands. These include the Kerguelen Islands, which are a French overseas territory. The Heard and McDonald Islands are also part of the plateau and belong to Australia.

This massive structure was created by the Kerguelen hotspot. A hotspot is a source of intense heat deep within the Earth. This heat causes magma to rise toward the surface. The process began around 130 million years ago, following the breakup of the supercontinent Gondwana. As the Antarctic Plate moved over this hotspot, layers of volcanic rock built up. This continuous volcanic activity created the vast plateau we see today. Some parts of the plateau, like the Heard and McDonald Islands, still experience intermittent volcanism.

The plateau is made of several distinct geological parts formed at different times. The Southern Kerguelen Plateau (SKP) formed between 120 and 110 million years ago. The Elan Bank formed shortly after, between 108 and 107 million years ago. Dennis E. Hayes of the Lamont Doherty Earth Observatory named this bank. The Central Kerguelen Plateau (CKP) appeared between 101 and 100 million years ago. Another section, the Broken Ridge, was once connected to the CKP before it rifted away. The Northern Kerguelen Plateau (NKP) formed much later, between 35 and 34 million years ago.

Geological history shows how the plateau influenced the movement of continents. During the breakup of India and Australia, the Kerguelen hotspot produced several structures. The Bunbury Basalt in Western Australia formed between 137 and 130.5 million years ago. The Naturaliste Plateau also formed around this time, between 132 and 128 million years ago. These events are linked to the opening of the eastern Indian Ocean. The hotspot output peaked between 120 and 95 million years ago. This peak occurred after the India-Antarctica breakup had already happened.

Parts of the plateau were once part of a continent. The Elan Bank and parts of the SKP were originally attached to India. These areas are made of continental lithosphere, which is the thick outer layer of a continent. As India moved northward, ridge jumps caused these fragments to be left behind. This process transformed the Elan Bank into a microcontinent. A microcontinent is a small piece of land that was once part of a larger continent. The plateau's development also contributed to an oceanic anoxic event 1. This was a period when ocean waters lacked enough oxygen.

Long ago, much of the plateau was above sea level. It was a microcontinent that sat in the open ocean. Scientists found soil layers in the basalt that contained charcoal and gneiss fragments. This charcoal came from wildfires caused by lightning or lava flows. During the mid-Cretaceous and early Cenozoic, the area may have had dense conifer forests. Fossil wood fragments found on the Kerguelen Islands were identified as Araucarians and Cypresses. These plants were similar to the flora found in Antarctica. The plateau finally became fully submerged about 20 million years ago.

Even though it is mostly underwater, the plateau is vital for marine life. It acts as a physical barrier that steers the Antarctic Circumpolar Current. When the current hits the plateau, it is pushed upward. This process brings nutrient-rich Upper Circumpolar Deep Water to the surface. These nutrients act as food for many different species. Because of this, the area has a high density of migratory whales. During the austral summer, sperm, minke, and humpback whales gather here to forage.