Researchers say ice drifting into tanker lanes will be smaller but more numerous in future

By Alan Sorum Council Project Manager Columbia Glacier, located in the Chugach Mountains of Alaska, is losing mass faster than almost any other glacier in the state. Columbia is a tidewater glacier, a type of valley glacier that flows into the ocean. In 1996, the council began a project to monitor and analyze the calving and drift of ice from the glacier, through Columbia Bay, and into Prince William Sound. The ice sometimes drifts into the established tanker shipping lanes. Loaded tankers leave their designated lanes to avoid this ice. In 2012, the council began to update information developed in the original 1996 project to determine the future risk of Columbia Glacier icebergs to the tanker traffic. Funded by the council, researchers W. Tad Pfeffer and Shad O’Neel studied several aspects of ice loss at Columbia Glacier. The study found that icebergs discharged by the glacier during the retreat have largely been contained within the moraine shoal, located at the position of the terminus prior to the glacier’s retreat. The fraction of icebergs that cross the moraine and enter Prince William Sound proper still pose a potential hazard to ship traffic in the Sound. … Continue reading

First known freshwater springs found beneath the face of Columbia Glacier

Researchers working with the council have found what are believed to be the first documented freshwater springs found at the base of a tidewater glacier in Alaska. This investigation was conducted by the Prince William Sound Science Center in support of ongoing council research focused on Columbia Glacier. Columbia Glacier has historically contributed to several maritime accidents related to the transportation of crude oil through Prince William Sound. The Glacier has been retreating rapidly from its terminal moraine near Heather Island since the early 1980s. Columbia Glacier’s main face is some 11 miles from Heather Island now. Icebergs produced by the glacier routinely cross into marine traffic lanes, posing a risk to crude oil tankers and their support vessels. “The survey found several small freshwater springs in the bottom of the bay – places where fresh, clear water was seeping out of the bottom and mixing with the cloudier, saltier water of the bay, “ said Dr. Robert Campbell, researcher for the Prince William Sound Science Center. … Continue reading