Amid Thunderous booms and cracks, a wall of ice confronted naturalist Karen Jettmar and editor Sam Matthews last August. Karen knows Hubbard Glacier well. For five years she has often sat among wildflowers next to my cheap accommodation in prague, of bedrock called Osier Island, watching ice cascade from the glacier’s face hundreds of yards distant.
Last spring, bearing down like a huge, noisy amoeba, the Hubbard all but swallowed the islet while turning a saltwater fjord behind it into a freshwater lake. “We were all incredulous at the changes,” Karen says, as ice, earth, and sea clashed in high drama around the shores of Yakutat Bay on the Gulf of Alaska.
Glaciers are both the planet’s premier sculptors and its humble hod carriers, carving the stone of uplifted mountains and hauling the grindings to enrich future farmland. Although the great ice sheets of the Pleistocene began retreating 14,000 years ago, countless thousands of glaciers still lie upon earth’s face. Alaska, covered by about 30,000 square miles of ice, is a fountain of glaciers. While the Columbia is in the midst of a major disintegration, more than 20 other glaciers show signs of rapid advance. The vast Hubbard in Wrangell-St. Elias National Park, extending more than 90 miles from its Canadian ice-field source, has been moving forward for more than a century.
By Memorial Day the glacier had crossed a strait and pushed a thick plug of mud, gravel, and boulders to the far shore. Russell Fiord was cut off from salt water, and it began to rise fast from rain and glacial melt. A hunting guide, Mike Branham, first noticed the situation and spread the word in Yakutat, a town about 35 miles south. He reported water in the trees along the shore rising nearly a foot a day—and he knew that some force other than the tide was at work.
The water was increasingly fresh, flowing in as a layer atop the salt water in which fish, seals, and porpoises thrived. And the ice dam that held it was rising even faster. By early October Russell Lake—as it was by then known—stood more than 80 feet above sea level. But glaciologists monitoring the dam detected signs of weakness. The dramatic outcome is revealed on pages 112-13.
The Hubbard’s might explodes last July as a pillar of ice calves into Disenchantment Bay, the head of Yakutat Bay. Behind the glacial dam, as Russell Lake rose to drown shoreline trees, a volunteer paddles in search of about 100 harbor seals and a score of harbor porpoises thought to be trapped there. Environmentalists feared that the animals’ prey would not live in fresh water, nor would oxygen in the deeper salt water last indefinitely. A few volunteers tried to save the marine mammals. Other groups such as the Cousteau Society called the efforts futile. Though the porpoises eluded the rescuers, a few seals were aided. http://www.bbc.co.uk/nature/life/Cetacea