Glaciers on Mt. Shasta keep growing - Democratic Underground

depakid

(1000+ posts) Send PM | Profile | Ignore

Wed Jul-09-08 04:58 AM
Original message

Glaciers on Mt. Shasta keep growing

Reaching more than 14,000 feet above sea level, Mt. Shasta dominates the landscape of high plains and conifer forests in far Northern California.

While it’s not California’s tallest mountain, the tongues of ice creeping down Shasta’s volcanic flanks give the solitary mountain another distinction. Its seven glaciers, referred to by American Indians as the footsteps made by the creator when he descended to Earth, are the only historical glaciers in the continental U.S. known to be growing.

With global warming causing the retreat of glaciers in the Sierra Nevada, the Rocky Mountains and elsewhere in the Cascades, Mt. Shasta is actually benefiting from changing weather patterns over the Pacific Ocean.

“When people look at glaciers around the world, the majority of them are shrinking,” said Slawek Tulaczyk, an assistant professor of earth sciences at the University of California, Santa Cruz.

“These glaciers seem to be benefiting from the warming ocean.”

Warmer temperatures have cut the number of glaciers at Montana’s Glacier National Park from 150 to 26 since 1850, and some scientists project there will be none left within 25 to 30 years.

The timeline for the storied snows at Africa’s Mount Kilimanjaro is even shorter, while the ice fields of Patagonia in Argentina and Chile also are retreating.

It’s a different story at Mt. Shasta, the southernmost volcano in the Cascade Range that is about 270 miles north of San Francisco.

Scientists say a warming Pacific Ocean means more moist air sweeping over far Northern California. Because of Shasta’s location and 14,162-foot elevation, the precipitation is falling as snow, adding to the mass of the mountain’s glaciers.

“It’s a bit of an anomaly that they are growing, but it’s not to be unexpected,” said Ed Josberger, a glaciologist at the U.S. Geological Survey in Tacoma, Wash., who is currently studying retreating glaciers in Alaska and the northern Cascades of Washington.

Historical weather records show Mt. Shasta has received 17 percent more precipitation in the last 110 years. The glaciers have soaked up the snowfall and have been adding more snow than is lost through summer melting.

The additional snowfall has been enough to overcome a 1.8 degree Fahrenheit rise in temperature in the last century, according to a 2003 analysis by Tulaczyk, who led a team studying Shasta’s glaciers.

By comparison, the glaciers in the Sierra Nevada, which are about 560 miles south of Mt. Shasta, are exposed to warmer summer temperatures and are retreating.

The Sierra’s 498 ice formations — glaciers and ice fields — have shrunk by about half their size over the past 100 years, with those exposed to direct sunlight shrinking fastest, said Andrew Fountain, a geology professor at Portland State University who has inventoried the glaciers in the continental U.S. as part of a federal initiative.

He said Shasta’s seven glaciers are the only ones scientists have identified as getting larger, with the exception of a small glacier in the shaded crater of Washington state’s Mount St. Helens. It formed after the 1980 eruption blasted away slightly more than half the mountain’s ice, and scientists believe it will not grow in area once it stretches outside the shade of the crater.

More: http://www.pressdemocrat.com/article/20080708/NEWS/17611494/1350&title=Shasta_s_glaciers_keep_growing#