Columbia Glacier is the largest tidewater glacier in Prince William Sound and the second largest tidewater glacier in North America. This glacier is accessible through several local tour operators.
Columbia Glacier Facts
Written by Alan Sorum
Columbia Glacier has been in a state of rapid retreat since the early 1980s, having retreated some 17 kilometers and undergoing a reduction in mass of about 150 cubic kilometers. Most of the glacier mass reduction has been in the form of calved icebergs. Icebergs flushed out of Columbia Bay drift with the current and wind into an area near the Valdez Narrows, running towards Bligh Reef. During certain periods, icebergs can drift surprisingly far into the greater Sound.
- Columbia Glacier is calving about 3.4 million tons of ice per day.
- The distance from the glacier’s terminus to the Heather Island Moraine is about 13.7 miles and from the moraine to the tanker traffic lanes is approximately 12 miles.
- The height of the glacier’s terminus ranges from 33 to 92 feet.
- Constrained by water depth at the moraine, the largest icebergs that can reach the traffic lanes are 328 feet (at their largest dimension).
- The main branch of the Columbia Glacier is now about 29.8 miles in length, down from the onset of the current retreat in the early 1980s of 43 miles.
- The water depth at the terminus ranges from 26 to 260 feet, much less than in late 1980s when it was more than 1,600 feet deep.
- The entire width of the terminus is about ten mile across, with the area of active calving at approximately 1.8 miles in width.