![]() “Even if we don’t get any future warming, it can’t survive this climate. “There’s no hope of saving it,” Pelto said. Sensitive aquatic species, like salmon, will struggle.ĭecades from now, Columbia will cease to exist altogether, and Blanca Lake’s bright-green water, the result of glacial runoff, will turn azure, according to scientific projections. Summer stream flows aren’t what they once were, Pelto said, having decreased 26 percent. The loss could translate into challenges downstream. If you can’t have a persistent snowpack, you can’t survive as a glacier.” “It’s overall volume is dissipating so quickly. “Columbia Glacier is just deflating,” Pelto said. It’s lost 22 percent of its mass during that time. It’s thinning faster than it’s retreating, Pelto said, losing 17 meters in thickness since 1984. The density of North Cascade glacier snowpack has been found to be essentially to within the range of accuracy of the measurement instruments (0.580.60 g/cm 3) constant by August and density measurements are only completed during June measurements (Pelto, 1996 Krimmel, 1999). Take for example Columbia Glacier, nestled above Blanca Lake in the Monte Cristo region. The formations feeding into the Skykomish River Basin are disappearing in slow motion. Pelto, who makes annual treks to Washington to monitor climate changes, has seen firsthand how glaciers have shrunk. “Even a little bit cool would not be enough.” mu.equiv/L.) The composition of the waters in terms of alkalinity and calcium concentration was similar to that of nonacidified waters of northwestern Norway and northwestern Ontario.“The odds of that aren’t real good,” he said. All of the source lakes were found to be susceptible but not acid, with alkalinities ranging from 4 to 190. Twenty-nine watershed source lakes lying along the Cascade Crest 3-20 miles north of the precipitation collectors were sampled during the summer of 1981. The strong more » acid content of the samples was observed to increase in the summer months. The sulfate deposition for 1981 at the Cascade Crest is estimated to be 16.0 kg ha/sup -1/ year/sup -1/ of SO/sub 4/ (sea salt corrected). The average strong acid composition in terms of sulfate and nitrate over the five collector sites ranged from 57 to 62 equiv % sulfuric acid. The volume weighted average pH over the collection period at the Cascade Crest (Snoqualmie Pass) was 4.71. « lessīulk precipitation was monitored at five sampling sites across the Cascade mountains east and windward of the urban Puget Sound area January 1981 through July 1981. This suggests that the pattern of snowpack melt and especially the pathway the meltwater follows to the stream may be important factors in determining whether stream water chemical pulses occur. ![]() An estimated 30% of the SO/sub 4//sup -2/ in the lake was derived from the = concentration, the magnitude and rate of concentration change was as great in a year of small peak snowpack ion load as it was following a more rapid ion loss from a larger snowpack load. By comparing lake water NO/sub 3//sup -/ concentrations to snowpack concentrations, over 75% of the NO/sub 3//sup -/ in the lake could be attributed to a snowpack source. During snow melt runoff there was no apparent neutralization of bicarbonate by strong acids. Acid neutralizing capacity at the lake outlet during snow melt was diluted to 50% of April premelt values. mu.eq L/sup -1/, respectively, and mean pH was 5.48. ![]() By July, mean NO/sub 3//sup -/ and SO/sub 4//sup -2/ concentrations were 0.32 and 1.73. During melting, anion levels in the snowpack decreased and pH increased. Mean concentrations of NO/sub 3//sup -/ and SO/sub 4//sup -2/ from North Cascades snowpack were near 4.5 and 5.5. Integrated snowpack samples and lake water samples were collected from a low-alkalinity watershed in the North Cascades in 19 and analyzed for inorganic chemical parameters.
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