The sinkhole was first discovered by Uralkali's Solikamsk-2 mine workers on November 18. According to local emergency services, it's located some two miles from the mine itself, in an old abandoned mine.
Old, out-of-use garden patches were affected by the accident, and there is no danger to locals, as the sinkhole is in no close proximity to any residential buildings, the company said.
The company that owns it, Uralkali has now stopped working in mines, evacuated the area and asked the 2,000 workers to stay home.
A part of the mine collapsed in 1995, causing an explosion of gas. Incidents of this kind can take place regardless of the protective measures taken by the miners.
There are opinions of experts who say that this crater, as the earthquake that took place here in 1994 were caused by a strong undercurrent of gas produced under pressure, which is common near the salt mines.
Under normal conditions gases or liquids under the high-pressure underground reason that they are, in fact, a support on which the soil located above them. Following extraction of human actions that support their gravity disappears and impose new tasks on the layer above the ground. Their calculations very well developed that can show whether after the extraction process will resist soil layer or not. Cases after extraction occurred soil subsidence, are numerous throughout the planet, which means that very important is who makes these calculations and takes responsibility for starting the extraction.
Worthy of notice is the effect they have compounds resulting from dissolving the salt in water in the presence of lack of air and gas in a confined space.
While the company says the development is no further threat, locals fear the whole nearby town could go underground.
There are no "catastrophic" effects of the sinkhole neither for the company nor for the locals, Uralkali CEO Dmitry Osipov said, adding that the incident has been localised.
Before the giant hole appeared near the town of Solikamsk, the company, which is Russia's biggest potash miner, evacuated workers at the Solikamsk-2 mine, due to the inflow of saline water. Operations at the site have been halted, and the level of underground water is being monitored.
Locals fear that the hole could get bigger and swallow their houses, which are some 2 miles from the sinkhole now. Regional authorities say the sinkhole could get bigger, but would still be of no danger to people.
The flooded mine, Solikamsk-2, is connected to another mine, Solikamsk-1, which is causing concerns among people in the region. The underground tunnels linking the two were walled up decades ago, but water would only need time to break through, people fear.
The town of Solikamsk is located "almost entirely" above the Solikamsk-1 mine, according to the town's mayor, Sergey Devyatkov, v-kurse.ru reported. If the mine is flooded - which could happen in theory, but not in the immediate future - the whole town would have to be evacuated, according to the source.
"There is no need to talk about the first mine now. All is good there," the mayor said in an interview with Russia's KP daily, adding that the situation is monitored around the clock, and there is plenty of time for observation.
Uralkali said that Solikamsk-1 and Solikamsk-2 mines border each other, and together with leading geologists the company is monitoring all processes in both of the mines, which produce potash chloride, to be used primarily as a crop nutrient. The company's facilities in the area have previously been affected by similar incidents. Uralkali's oldest mine was shut down in 2006 due to water inflow, which also caused a sinkhole to form in the town of Berezniki, which is the second largest town in Perm region.
Another sinkhole appeared in Berezniki in 2011, when a round hole as wide as 137 meters (450 feet) formed less than a mile away from a residential area.