A23a facts for kids

A23a is a giant, flat-topped iceberg that broke off from the Filchner–Ronne Ice Shelf in Antarctica in 1986. For many years, it was stuck on the ocean floor, but it started moving again in 2020. This iceberg is about 3,900 square kilometers (1,500 sq mi) in size. This made it one of the largest icebergs in the world, until A76 became even bigger for a short time.

What is Iceberg A23a?

A23a is a very large piece of ice that has broken off a glacier or ice shelf. It is called a tabular iceberg because it has a flat top and steep sides, like a huge floating table.

Where did A23a come from?

A23a broke off, or calved, from the Filchner–Ronne Ice Shelf in Antarctica. This happened in 1986. Ice shelves are thick, floating platforms of ice that form where glaciers flow off the land and onto the ocean.

How big is Iceberg A23a?

Iceberg A23a is enormous! It covers an area of about 3,900 square kilometers (1,500 sq mi). To help you imagine its size, that's roughly three times the size of the city of Los Angeles, or bigger than some small countries. For a while, it was the biggest iceberg on Earth. Later, another iceberg called A76 became even larger, but A23a is still one of the biggest.

A Moving Giant

After it broke off in 1986, A23a got stuck on the seabed, which is the bottom of the ocean. It stayed there for many years, like a giant, frozen island. But in 2020, it finally started to move again. In November 2023, scientists watched as A23a floated past the northern tip of the Antarctic Peninsula. It is now heading towards the Southern Ocean.

The Druzhnaya 1 Base

Before A23a broke off, a science base called Druzhnaya 1 was located on this very piece of ice. When the iceberg calved in 1986, the base was suddenly on a giant floating ice island! A rescue mission was quickly started in 1987 to move the base and its equipment to safety. The base was later renamed Druzhnaya 3.