Where do North Atlantic icebergs come from?
The principal origin of those icebergs that reach the North Atlantic Ocean are the 100 or so major tidewater glaciers of West Greenland. Between 10,000 to 15,000 icebergs are calved each year, primarily from 20 major glaciers between the Jacobshaven and Humboldt Glaciers.
Glaciers are formed by thousands of years of snowfall accumulation which eventually is compressed into ice. It is estimated that these glaciers account for 85% of the icebergs which reach the Grand Banks of Newfoundland. Other sources of icebergs are the East Greenland glaciers, which produce about half the amount of icebergs as the West Greenland glaciers, but account for only 10% of the icebergs reaching the Grand Banks. The remaining 5% are thought to come from glaciers and ice shelves of northern Ellesmere Island.