Laser altimetry data shows the surface of the lower glacier has risen vertically by an average of 30 to 50 meters since November 2007. The ice front closest to the river has advanced forward roughly 350 m since November 2007. From where the ice front is now in the river, the glacier has another 350 to 400 m to cross the river bed.Just 50 to 100 m back from the ice front, the ice thickness is 50 to 100 m (again, from repeated laser measurements). Will it dam the Alsek? Surges are unpredictable. It could stop today, it could go all summer. Once the spring melt gets the river stage up, the Alsek may be able to overwhelm the advancing ice. Whatever happens, it should be interesting.
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