americangeophysicalunion:Small mountain glaciers play a big role in recharging vital aquifers and in
americangeophysicalunion:Small mountain glaciers play a big role in recharging vital aquifers and in keeping rivers flowing during the winter, according to a new study published in Geophysical Research Letters, a journal of the American Geophysical Union.The study also suggests that the accelerated melting of mountain glaciers in recent decades may explain a phenomenon that has long puzzled scientists – why arctic and subarctic rivers have increased their water flow during the winter even without a correlative increase in rain or snowfall.These photos show University of Alaska Fairbanks researcherAnna Liljedahl coring the glacier snow pack on Jarvis Glacier to measure snowdensity in order to estimate how much water is stored in the later winter snowpack before the snow melts, and putting up a wind shield around a gauge thatshe installed on Jarvis Glacier to measure rainfall. They also show UAFresearchers hiking between the glacier mass balance stakes on Jarvis Glacier tomeasure how much snow and ice melted over the summer, and taking a water samplefor geochemical analysis at the mouth of the Jarvis Glacier. The bottom images show a before and after photo of Gulkana Glacier. Thetop photo shows the Gulkana Glacier in 1967 when the US Geological Surveystarted their glacier mass balance monitoring program. The bottom photo is 49years later in 2016 and shows the shrinkage of the glacier extent. The totalloss of water from the glacier retreat equals a 25m deep water column spreadout across the entire recent glacier area. Read more at http://blogs.agu.org/blog/2017/07/21/mountain-glaciers-recharge-vital-aquifers/Photo credits: USGS (Gulkana Glacier), Todd Paris/University of Alaska. -- source link
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