'It was scary': Earthquake hits Esterhazy, Sask.

An earthquake hit Esterhazy and area around 8:30 p.m. CST Thursday night. The U.S. Geological Survey says the quake measured 4.1 in magnitude, and was centred about five kilometres below the surface.

Power knocked out, all miners accounted for underground

A 4.1-magnitude earthquake shook the Esterhazy area, knocking out power to several communities Thursday night. (U.S. Geological Survey)

The Esterhazy, Sask., area was hit with an earthquake Thursday night.

The U.S. Geological Survey says the quake, which rocked the area around 8:30 p.m. CST, was 4.1 in magnitude, and was centred about five kilometres below the surface. The epicentre was at Mosaic's K2 potash mine at Gerald, Sask.

None of the 120 or so employees who were underground at Mosaic's three mines in the area were injured nor was any property damaged, said company representative Sarah Fedorchuk.

She said the workers immediately gathered at pre-marked "muster points" in the mine so they could all be accounted for, not because of the earthquake itself but because the power went out.

"After we accounted for all employees it was business as usual. They completed their shift in the regular way and then went home," Fedorchuk said.

SaskPower said three of the four transformers at the Tantallon switching station tripped within minutes of the earthquake.

"A piece of transformer equipment called a gas relay that responds to gas leaks or sudden pressure changes was set off by vibrations caused by the earthquake," a SaskPower representative said in an email.

The lights went out around 9 p.m. CST in Esterhazy, Whitewood, Moosomin, Rocanville, and a number of other surrounding communities. Power was restored about two and a half hours later. SaskPower said the reason for the delay is that the transformers needed to be checked over and manually reset.

Tracy Moore was playing with her grandchildren when her Tantallon-area farmhouse started shaking, for about three to five seconds, and the power went out. Moore said the children screamed and cried.

"The youngest thought she was going to die. It was scary for them," Moore said.

Her family didn't want to head downstairs in the dark on Thursday night to see if the quake damaged the concrete, so she will find out on Friday if anything was damaged.

Earthquakes common in area

The community has been struck by earthquakes before. In the fall of 2016, there was an 3.8-magnitude earthquake. There have been 17 earthquakes around that magnitude in the Yorkton-Esterhazy area since 1981.

Fedorchuk says the area is known for its seismic activity and that there is always a level of seismic potential when mining. 

CBC previously spoke to a Andrew Frederikson, a seismologist at the University of Manitoba. He said the high prevalence of earthquakes in the area is due to the makeup of the earth in the area, not necessarily because of potash mining, although that can contribute to it.

Frederikson said potash dissolves in water, which can make a lot of changes to the water table and cause earthquakes.

While there has been some seismic activity in Saskatchewan, it is linked to potash mining, not fracking for oil.

Frederiksen said he's aware of fracking in southeast Saskatchewan and southwest Manitoba, but says there's no indication of any earthquake activity.

There is a small cluster of seismic activity around Esterhazy, but "that has more to do with potash mining than anything the oil and gas industry might be doing," Frederiksen told CBC News in a May 2019 interview.