Tasmanian Passage

The Tasmanian Passage, also called the Tasmanian Gateway or Tasmanian Seaway, is the area of ocean water between Australia and Antarctica. It formed when the continents of Australia and Antarctica moved apart about 30 to 40 million years ago, allowing water to flow between them around 33.5 million years ago.

This passage connects the Indian Ocean with the Pacific Ocean to the south of Australia. The distance between the two continents today is about 2,300 kilometres or 1,400 miles.

The opening of the Tasmanian Passage, together with the Drake Passage, allowed the Antarctic circumpolar current to form during the Oligocene period. This current replaced older water flow patterns from the Cretaceous and helped isolate Antarctica thermally. Because warm equatorial waters could no longer mix with colder waters, Antarctica's ice sheets grew, leading the Earth to enter the Late Cenozoic Ice Age, the ice age we are still in today.