A massive sinkhole, the largest in the last 20 years, formed in a parking lot between the Fireside Diner and a Chevron gas station along US 101 in Harbor, Oregon, and caused a part coastal highway in the area to close down during the last week. The hole, caused by torrential rains, initially formed on December 13, 2015, and increased greatly in size since. No injuries or vehicle incidents were reported.
The void was initially 2.1 m (7 feet) deep and the size of a volleyball, according to Jared Castle, the Oregon Department of Transport (DOT) spokesman for southwest Oregon.
Video credit: Dave Lovell
The sinkhole is currently 24.4 m (80 feet) in diameter: "It’s a monster for sure. This is a very unusual event and is a sinkhole of a magnitude that we don’t see but once every couple decades," Castle said.
The new hole formed next to another 15.2 m (50 feet) wide sinkhole which appeared in November 2015, during a period of heavy rainfall in the region. During its formation, the crack swallowed two tractor-trailers and plunged them about 15 m (50 feet) below the road. Luckily, no serious injuries occurred.
Video credit: Kyle Rice
The crews have been working to clear a blockage in an underground drainage, caused by the sinkhole formation. The blockage influenced water flow in the area, forcing it to change its route to the sea from the local hills, and thus caused more such voids to open up in the affected area.
Video credit: Kyle Rice
According to local authorities estimates, it will take 49 696 cubic m (65 000 cubic yards) of material to fill the holes and shore up the adjacent slope.
Featured image: Oregon sinkhole, January 29, 2016. Image credit: Kyle Rice
