A massive iceberg twice as big as the city of Toronto broke off Antarctica on Friday, according to a news release from the British Antarctic Survey (BAS). The BAS operates a base on the Brunt Ice Shelf, where the 1,270 square kilometre iceberg — nearly one-third the size of Prince Edward Island — broke off.The Halley Research Centre, which is closed for the Antarctic winter, is unlikely to be impacted by the event, the organization said in the release. "Our teams at BAS have been prepared for the calving of an iceberg from Brunt Ice Shelf for years," BAS director Jane Francis said in the statement. Calving is the scientific term used to describe ice breaking off from a glacier. "Over coming weeks or months, the iceberg may move away; or it could run aground and remain close to Brunt Ice Shelf," Francis said. "Halley Station is located inland of all the active chasms, on the part of the ice shelf that remains connected to the continent." In November, a new chasm in the Brunt Ice Shelf — which the organization named the North Rift — headed toward another large chasm, the BAS said in its statement. It was the third major crack to become active in the last decade and eventually cut through the 150-metre thick ice shelf and released, the organization said. BAS said changes in the ice at the research centre is a "natural process" and said there is "no evidence that climate change has played a significant role."