curiopediaFive-minute reads on the curious world

Browse by tag

    Earth3 min read

    How thick is the ice in Antarctica?

    About 2 kilometers on average. At its thickest it tops 4,700 meters, enough to bury Mount Fuji completely.

    4757m

    Thickest ice in Antarctica (2025 estimate)

    Almost all of Antarctica is covered in snow and ice. The ice spreads over about 14 million square kilometers (5.4 million square miles), roughly 36 times the area of Japan.

    Looking down from above, though, tells you nothing about how thick that ice is. Antarctica’s ice sits on the continent like an enormous slab. How thick is this ice sheet?

    About 2 kilometers on average

    In March 2025, an international team led by the British Antarctic Survey released Bedmap3, a new map of the thickness of Antarctica’s ice and the landscape beneath it. It draws on 82 million data points gathered by many countries over about 60 years.

    According to Bedmap3, the ice sheet averages about 2,150 meters (7,050 feet) thick. Even including the floating ice shelves that extend out over the sea, the average is still about 1,950 meters. That is more ice than three Tokyo Skytrees (634 meters each, the tallest tower in Japan) stacked on top of each other, covering an entire continent.

    In all, there are about 27 million cubic kilometers of ice. If it all melted, global sea level would rise by roughly 58 meters (190 feet).

    A flat white snowfield stretching into the distance, rippled by the wind, with a snow vehicle parked far off
    The snow surface of Antarctica’s inland plateau, with a snow vehicle. Beneath the snow underfoot lies ice thousands of meters thick.Source: Stephen Bannister / CC BY 2.5 / Wikimedia Commons

    4,757 meters at its thickest

    So where is the ice thickest? It used to be thought that the deepest ice lay in the Astrolabe Basin in Adélie Land, East Antarctica. When the data were re-examined for Bedmap3, however, the record went to an unnamed canyon farther west in Wilkes Land, where the ice is 4,757 meters (15,600 feet) thick.

    Mount Fuji, Japan’s highest peak, stands 3,776 meters tall. Sink the whole mountain into that spot, and there would still be nearly 1,000 meters of ice above its summit.

    Below the ice, below sea level

    What lies under ice that thick? Surveys with radar that can see through ice show that Antarctica’s bedrock has high mountain ranges as well as deep valleys and basins.

    Antarctica seen as if from space with its ice removed: brown mountain ranges and basins surrounded by gray seafloor
    The shape of Antarctica’s bedrock with all of its ice removed, drawn by NASA from Bedmap2, a dataset compiled by the British Antarctic Survey and others.Source: NASA Goddard's Scientific Visualization Studio / Public domain / Wikimedia Commons

    Some of it lies far below sea level. In 2019, a team led by the University of California, Irvine, revealed that the floor of a trough beneath Denman Glacier in East Antarctica lies more than 3,500 meters (11,500 feet) below sea level. That makes it the lowest point on land anywhere on Earth. Even the shore of the Dead Sea, famous as the lowest exposed land, is only a little over 400 meters below sea level. In West Antarctica too, the bedrock drops more than 2,500 meters below sea level in places.

    Drilling 3,000 meters of ice

    The ice sheet formed from snow that piled up over hundreds of thousands of years and was pressed into ice without ever melting. The deeper you drill, the older the ice, so air bubbles trapped inside can reveal what Earth’s climate was like long ago.

    Japan has taken on this challenge too, at Dome Fuji Station, about 1,000 kilometers (620 miles) south of Japan’s Syowa Station, sitting on the ice sheet at an altitude of 3,810 meters. The average annual temperature there is below minus 50°C (minus 58°F), and the air pressure is around 600 hectopascals, lower than on the summit of Mount Fuji. In January 2007, a Japanese team succeeded in drilling down to a depth of 3,035 meters. The deepest ice is about 720,000 years old, and this column of ice records Earth’s history of alternating cold glacial periods and warmer interglacials.

    A new drilling project now aims to recover even older ice, more than a million years old. As of January 2026, it had reached a depth of about 1,784 meters.

    Read next

    1. Earth4 minHow hot is the center of the Earth?More than 6,000 kilometers beneath your feet lies a place no one has ever been. How did scientists work out its temperature?
    2. Earth4 minWhat is the longest river in the world?Your atlas has an answer. But some researchers aren’t convinced by it—because measuring a river turns out to be far harder than it sounds.
    3. Earth3 minWhich is colder, the Arctic or the Antarctic?Both are frozen worlds at the ends of the Earth. The two polar regions seem like twins, but what lies beneath their ice could hardly be more different.
    4. Earth4 minWhat’s the difference between magnitude and seismic intensity?Two numbers come up in every earthquake report. They look alike, but they actually measure completely different things.
    5. Earth3 minHow hot is lightning?For the briefest instant, a single streak of light carves a path hotter than the Sun. And that deafening roar comes from the very same heat.
    6. Earth3 minWhy do volcanic eruptions make lightning?Bolts of lightning flash through a towering black plume of ash. There is no thundercloud, so why does lightning strike above a volcano? The phenomenon appears even in Japanese records from the eighth century.
    7. Earth4 minIs it true that no two snowflakes are alike?“No two snowflakes are alike,” people say. But has anyone actually checked? Each flake, it turns out, carries a record of its journey through the sky.
    8. Earth4 minWhy do auroras glow?Curtains of light rippling across the night sky. We think of them as a polar sight, yet they were recorded in Japan as far back as the seventh century.
    Read a random articleBrowse all articles