Giant sinkhole formed in Russian Perm region in the Ural Mountains shortly after a potash mine near town of Solikamsk flooded. The sinkhole, stretching 20 by 30 metres, was found 3.5 km east of the Solikamsk-2 potash mine in Russia's Perm region.
The sinkhole was first discovered by Uralkali's Solikamsk-2 mine workers on November 18, 2014. It is located on an abandoned mine and does not pose a direct threat to residents of Solikamsk town.
The town of Solikamsk is located almost entirely above the Solikamsk-1 mine, according to the town's mayor, Sergey Devyatkov. Saint-Petersburg Geology Institute is deployed to investigate the reason for the brine inflow and its relation to the sinkhole.
Aerial view of Solikamsk sinkhole. Images taken on November 20, 2014. (Image courtesy: Uralkali press service)
The world's largest potash producer Uralkali suspended all work after high levels of brine inflow were detected. A water inflow and resulting sinkhole in 2006 shut another Uralkali mine at Berezniki-1 in the same region permanently. Another two of Uralkali's Berezniki mines, also in the Perm region, have been hit since 1984. Flooding is a common problem for the potash industry.
The Solikamsk-2 plant has an annual capacity of 2.3 million tonnes of potash. Company estimate that up to 24 percent of the company's capacity might be affected, with another 20 percent of capacity in geographical proximity to the flooded mine.
Location of the Upper Kama potash deposits. (Credit: Chris Damas/SeekingAlpha)
Some experts do believe that producing Solikamsk-1 mine adjacent to flooded Solikamsk-2 mine, is likely to be flooded also.
There are two safety barriers installed between mines - a 20 meters concrete wall and a 200 meters pillar, which entirely consists of potassium salt. New water inflow in flooded mine may create microfracture in a concrete wall by the time. Water may also penetrate through small tectonic fractures. Also 1994 earthquake that occurred in the same region, seem to have been caused by powerful underground currents of highly-pressurized gas commonly found around salt mines.
Cross-section of Solikamsk 1 and 2 mines. (Credit: V-kurse.ru)
Just a month ago, another sinkhole measuring nearly 85 meters wide and 15 meters deep swallowed few houses in the town of Buturlino, southeast of the city of Nizhniy Novgorod in central Russia.
Featured image: Aerial view of Solikamsk sinkhole. Images taken on November 20, 2014. (Image courtesy: Uralkali press service)