After months of drifting, the world’s largest iceberg has come to a halt near the island of South Georgia in the South Atlantic Ocean.

While a “Titanic II” scenario isn’t very likely, and the area’s penguins seem to be mostly safe, the berg may be a symptom of unwelcome change to the Antarctic and the planet.

How did we get here?

A23a, as the iceberg is officially known, was born in 1986 when it broke off from another iceberg, A23, that had torn away from Antarctica earlier that year. The separation of a smaller ice chunk from a larger one is called calving.

Its early life was uneventful; it sat in the Weddell Sea, east of the Antarctic Peninsula, for decades.

A23a’s travels began in 2020, when it freed itself from the sea floor and began to move. By 2023, it was ready to leave Antarctic waters entirely.