Interesting EventsHere we describe recent, rapid changes in the cryosphere that are newsworthy. They may or may not be significant in a climate context. |
 |
Rock Glacier Threatening Highway in Alaska
J. Key, 13 June 2017
A frozen mass of soil, rock, trees, ice, and other debris is very close to the Dalton Highway in Alaska (Figure 1). State officials now plan to move a 4000 ft (1220 m) section of the highway. The frozen debris lobe has been moving downhill for hundreds of years and is expected to reach the highway in the next 4-6 years. It is less than 100 ft (30 m) from the highway and is moving about 15 ft (4.6 m) annually. The Dalton Highway - referred to locally as the "Haul Road" - is critical to the economy of Alaska, as trucks use this route to bring supplies to North Slope oil production facilities.
Figure 1: Google Earth image of the frozen debris lobe in 2002 (the image year). The yellow pin indicates the location of the front of the lobe on 26 May 2017, as reported by Brian Brettschneider (University of Alaska-Fairbanks, International Arctic Research Center; UAF/IARC).
The frozen debris lobe is a rock glacier, which is a mass of rock fragments and finer material, on a slope, that contains either an ice core or interstitial ice, and shows evidence of present movement. This one is approximately 100 ft (30 m) thick near the front of the lobe and 850 ft (260 m) wide.
Pictures of the debris lobe taken on 26 May 2017(by Brian Brettschneider, UAF).
More information is available from the Alaska Dispatch News and the Frozen Debris Lobes website at the University of Alaska-Fairbanks.
