Geologic Publications for Mount Rainier
Mount Rainier National Park glacier mass balance monitoring annual report, water year 2010: North Coast and Cascades Network
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Jon L. Riedel
, Michael Larrabee
Natural Resource Data Series NPS/NCCN/NRDS-2012-355
National Park Service
Glaciers are excellent indicators of climate change and important drivers of aquatic and terrestrial ecosystems. There are currently 27 major glaciers at Mount Rainier National Park, which cover about 90 km2
. Since 2003, we have monitored the seasonal mass balance changes of two of these glaciers, Emmons (11.6 km2
) and Nisqually (6.9 km2
), using six measurement points per glacier. The purpose of this report is to describe and summarize data collected during the 2010 water year.
Measurement of winter, summer, and net mass balance on Mount Rainier is complicated by steep (inaccessible) ice falls, debris cover, and a 2000 m range in elevation. With the large vertical extent, glacial melt begins at the terminus in early April and above 3000 m in July. Maximum accumulation occurs between about 2000 and 2500 m elevation, with significant redistribution of snow by wind from southwest to northeast at higher elevations.
Winter snow accumulation reached a maximum depth of 3.40 m w.e. on Nisqually Glacier and 3.44 m w.e. on Emmons Glacier in water year 2010. Water equivalent (w.e.) values averaged across the entire glacier were 129% of the 2003-2010 average on Nisqually Glacier [+3.06 (±0.36) m w.e.] and 110% of average on Emmons Glacier [+2.49 (±0.44) m w.e.].
Maximum summer melt reached -4.34 m w.e. at stake 4 on lower Nisqually Glacier in late September. Net summer balance averaged across the measurement sites on Nisqually Glacier was -2.55 (±0.48) m w.e., and -2.36 (±0.55) m w.e. on Emmons Glacier (73% of average for both glaciers). Significant debris cover on the lower portions of both glaciers slowed average ice melt to 54-82% of melt observed on adjacent stakes on clear glacier surfaces.
In 2010, annual net mass balance was positive for Nisqually Glacier [+0.50 (±0.65) m w.e.], the only positive year since monitoring began in 2003. Emmons Glacier also had a slight positive balance [+0.13 (±0.70) m w.e.]. Despite the modest increases in glacier balance in 2010, the overall trend in cumulative balance has been strongly negative for both glaciers. Since 2003, the cumulative balance for Nisqually Glacier is -9.05 m w.e. and for Emmons Glacier it is -7.69 m w.e. The cumulative net volume loss in the past eight years is 89.2 M m3
and 61.2 M m3
for Emmons and Nisqually glaciers, respectively.
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In Text Citation:
Riedel and Larrabee (2012) or (Riedel and Larrabee, 2012)
Riedel, J.L. and M. Larrabee, 2012, Mount Rainier National Park glacier mass balance monitoring annual report, water year 2010: North Coast and Cascades Network: Natural Resource Data Series NPS/NCCN/NRDS-2012-355, National Park Service, 34 p..