Australian scientists said on Friday that a massive iceberg had broken off a glacier in Antarctica.

The iceberg calved off the Mertz glacier after being rammed by another large iceberg from the Ross Ice Shelf.

The new iceberg measures 78 kilometres by 39 kilometres and is 400 metres thick. It was discovered by Australian and French scientists who have been studying the glacier since 2007.

Glaciologist Neal Young from the Australian Antarctic Division told the Australian Broadcasting Corporation that an iceberg hasn''t broken off the Mertz glacier for at least 50 years.

"So this is probably about 80 percent of the floating tongue that extended out from the continent, the coastline and it''s a once in 50 to 100 years event," Young said.

Scientists said the event is not related to global warming. The glacier tongue had a major rift in it on both sides for years.

The iceberg holds enough fresh water to supply the earth''s human needs for a year.

Scientists are unsure as to where the iceberg will drift, but it''s expected to affect ocean currents.

"The immediate term is of major interest for us because we want to know how long it will take for the icebergs to clear the area and then we''ll look at where they go." Young said.