The Alaska Department of Transportation and Public Facilities says an early morning rockslide that crunched the front end of an SUV and closed down a portion of the Seward Highway for two hours Thursday was caused by weather.
DOT spokesperson Shannon McCarthy said the weather this week -- alternately freezing and thawing -- was likely the culprit. Temperatures Thursday morning were in the mid-20s, but earlier this week, Anchorage reached 44 degrees, breaking a 30-year-old high-temperature record.
"It's been pretty warm," McCarthy said. "We've had a little rain and a little snow too. And once water gets into a crack, it expands and contracts and it can make what would have been a solid rock into something that could fall." Heavy rain and earthquakes can also cause slides, McCarthy said.
According to a release from the Anchorage Police Department, sent shortly before 7 a.m., police responded to reports that a black Jeep Liberty had struck a rock that had fallen into a northbound travel lane.
Police said the driver only sustained minor facial injuries, which were primarily caused when the car's airbag deployed.
The highway opened up again shortly before 9 a.m. Northbound traffic was backed up about a mile.
McCarthy said DOT removed "several large boulders" and debris -- about two feet deep in areas -- from the roadway. Responding officers said some of the boulders were about the size of small automobiles.
McCarthy said although stretches of the Seward Highway are known to be high-risk areas for rockslides, Mile 113.7, near the Potter Marsh weigh station, is not among them.
"We are going to monitor this area," McCarthy said. "We have folks on the ground right now (late Thursday morning) taking a look at it."
The agency was considering bringing down additional rock that remained precariously in place above the roadway "in a safer fashion," McCarthy said, possibly using an excavator. The undertaking could cause DOT to close the road again "in the near future."
In April 2012, falling ice on the same stretch of the highway crushed a vehicle and injured a 32-year-old woman.
McCarthy said maintenance crews traveling down the Seward Highway are on a constant lookout for potential rockslides but asked members of the public to be on the lookout for possible dangers or fallen rocks. Should anyone notice a high-risk area or rockslide area of any measure, McCarthy said, they should call the DOT Anchorage Maintenance Station at 338-1466.
Later, on Thursday evening, a large piece of the ice wall on the cliffs next to the Seward Highway a short distance south of the earlier slide site came crashing down, covering both lanes with ice chunks. At least one car drove through the ice, catching a chunk underneath it and leaving a trail of ice dust as it dragged the ice down the road.?