PORTLAND, Ore. – The seven largest of Mount Hood's 11 glaciers have shrunk by an average of more than 30 percent since the beginning of the last century, according to calculations by a Portland State University graduate student. Keith Jackson, who is part of a glacier research team financed by the National Science Foundation and NASA, estimates that Sandy Glacier, on Mount Hood's west slopes facing Portland, covers about 60 percent less ground than it did a century ago and Eliot Glacier has lost at least half of its ice in the last 100 years.And scientists think glaciers might recede...