By DAVID LESTER, The Yakima Herald-Republic
8 January 2012YAKIMA, Washington (AP) – Spectacular on a clear, sunny day, Mount Adams rises a scant 53 miles from Yakima.
But the mountain holds what until now has been pretty much a secret.
In the first comprehensive study of its kind, a Portland State University study has found Mount Adams' 12 glaciers have shrunk by nearly half since 1904 and are receding faster than those of nearby sister volcanoes Mount Hood and Mount Rainier.
It's another sign of gradually warming temperatures that — if continued as expected by researchers — will mean significant problems for the water-dependent Yakima Valley.
The study lends urgency to an earlier federal report that shows the water content of Cascade Mountain snowpacks could dwindle by as much as 50 percent by the 2070s.
More rain and smaller snowpacks will result in water shortages because less water is projected to be available to support the Valley's agriculture in the hot summer months, according to that congressionally ordered report by the Bureau of Reclamation, Army Corps of Engineers and the Bonneville Power Administration.
The Yakima Valley already has had five economically damaging droughts since 1992. And while the Valley's water supplies don't come from the flanks of Mount Adams, the study carries implications for other parts of the south Cascades that do provide water for the Valley.
The latest work on glaciers on the 12,276-foot Mount Adams by a Portland State University geology professor and a student team was based on aerial photography, geographic information system mapping, buttressed by historic photos taken by hikers.
The results show Adams' glaciers have melted away 49 percent of their coverage area since 1904.
Over generally the same time period Mount Rainier's glaciers lost 24 percent of coverage area and on Mount Hood the decline has been some 32 percent.
Geologist and team leader Andrew Fountain, who has a total of 30 years of experience with the university and before that with the U.S. Geological Survey, isn't sure why. […]
"When temperatures are close to melting temperatures, a slight warming can shift from snow to rain. That is what has been happening. The precipitation hasn't changed much, but it is switching from snow to rain." […]
Ingrid Tohver, a research scientist with the Seattle-based team, said the team's work suggests the total amount of precipitation may not change very much. […]
"With any small bump in temperature, those basins are susceptible to these changes," she said. "With less snow, the summertime might look a lot drier."
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