Toronto ? A giant ice shelf has snapped free from an island south of the North Pole, scientists said Thursday, citing climate change as a “major” reason for the event.

The Ayles Ice Shelf – all 41 square miles of it – broke clear 16 months ago from the coast of Ellesmere Island, about 500 miles south of the North Pole in the Canadian Arctic.

Scientists discovered the event by using satellite imagery. Within one hour of breaking free, the shelf had formed as a new ice island, leaving a trail of icy boulders floating in its wake.

The ice shelf was one of six major shelves remaining in Canada’s Arctic. They are packed with ancient ice that is more than 3,000 years old. They float on the sea but are connected to land.