Article image

Biggest iceberg on Earth weighs one trillion tons and is floating freely in the open seas

New observations from space have unveiled the immense dimensions of the world’s biggest iceberg, known as A23a. This colossal ice mass covers an area of 1,500 square miles, has a volume of 263 cubic miles, and weighs nearly one trillion tons. 

To put this in perspective, A23a is four times the size of New York City and about 100 million times heavier than the Eiffel Tower in Paris.

Rough seas ahead for A23a

Resembling a tooth in shape, A23a was previously anchored to the ocean floor for 30 years. Now, it’s moving northward at a notable pace, driven by wind and ocean currents. 

As it drifts past the Antarctic Peninsula, which extends from the mainland like a tail, it is expected to encounter rougher seas and eventually break apart in the open ocean. 

Potential wildlife impacts

The British Antarctic Survey (BAS), which recently observed A23a, reported that the iceberg is traveling northward at approximately 30 miles per day. This movement could potentially disrupt the feeding patterns of local wildlife, such as penguins, especially if it obstructs typical foraging areas. 

“It depends on its trajectory, but there is potential for impact to wildlife if it approaches any of the sub-Antarctic islands,” a BAS representative said.

A23a is a free-floating iceberg

Originating from the Antarctic’s Filchner Ice Shelf in August 1986, A23a is the largest remaining piece of an initially larger iceberg. After drifting only a few hundred miles, it became grounded on the ocean floor, remaining stationary for the next three decades. 

An iceberg becomes “grounded” when its underwater portion, the keel, is deeper than the water’s depth. The European Space Agency’s CryoSat satellite identified that a section of A23a’s base extended particularly deep, acting like an anchor. Recently, scientists observed that the iceberg has begun moving again, guided north by wind and ocean currents.

Iceberg alley

The iceberg’s journey, monitored by the European Space Agency’s satellite, shows it nearing Clarence Island and Elephant Island, near the Antarctic Peninsula’s tip

“A23a has put a spurt on and is heading quickly away from Antarctic waters,” the agency commented on December 1. “Like most icebergs from the Weddell sector, A23a is likely to end up in the South Atlantic on a path known as iceberg alley.”

Lucky encounter with A23a

Researchers from BAS, aboard the British polar research vessel RRS Sir David Attenborough, recently photographed A23a, calling it a lucky encounter. They also collected samples of ocean surface waters along the iceberg’s route to study potential life forms around it and its impact on oceanic carbon levels.

American planetary scientist Lindy Elkins-Tanton, part of a team that visited A23a last month, shared images of the iceberg on social media, likening it to “sailing alongside a new country.” 

Currently the largest iceberg in the world, A23a’s status is temporary, as all icebergs eventually break down. As it travels north, warmer water temperatures will cause A23a to thin and eventually disintegrate and melt. The previous record-holder, iceberg A76, which separated from an ice shelf in the Weddell Sea in May 2021, has since split into three parts.

More about icebergs

As discussed above, icebergs are majestic and colossal formations of ice, captivating the human imagination for centuries. Originating from glaciers or ice shelves, these floating ice masses play a crucial role in the Earth’s natural systems.

Formation and characteristics

Icebergs begin their journey as part of glaciers or ice shelves. When chunks of ice break off in a process called calving, icebergs form. This phenomenon mainly occurs in the polar regions, particularly around Greenland and Antarctica.

Typically, icebergs display a stunning array of shapes and sizes. The largest can tower hundreds of feet above water and extend deep below the surface. They consist primarily of freshwater and contain air pockets, which can create captivating patterns and colors.

Their journey

After breaking away, icebergs drift with ocean currents and winds. Their paths, often unpredictable, can take them thousands of miles from their origin. During this journey, icebergs continuously melt and reshape.

As they melt, icebergs release freshwater and nutrients into the ocean, supporting diverse marine life. This influx of nutrients can lead to blooms of phytoplankton, forming the base of the marine food web.

Impact of climate change

Icebergs serve as vital indicators of climate change. The rate of iceberg calving can signify changes in the Earth’s temperature and the health of polar ice masses.

With rising global temperatures, the formation and lifecycle of icebergs are changing. Increased calving rates and melting are concerns for scientists studying the impacts of climate change on polar regions.

In summary, icebergs, with their immense size and beauty, are more than just a natural wonder. They play a significant role in the Earth’s ecosystems and act as indicators of our planet’s health. As we witness changes in their behavior and frequency, icebergs remind us of the ongoing challenges posed by climate change.


Like what you read? Subscribe to our newsletter for engaging articles, exclusive content, and the latest updates.

Check us out on EarthSnap, a free app brought to you by Eric Ralls and


News coming your way
The biggest news about our planet delivered to you each day