The 1996 Rocky Mountain House earthquake was a magnitude

Surface wave magnitude

The surface wave magnitude scale is one of the magnitude scales used in seismology to describe the size of an earthquake. It is based on measurements in Rayleigh surface waves that travel primarily along the uppermost layers of the earth...

 3.8 earthquake

Earthquake

An earthquake is the result of a sudden release of energy in the Earth's crust that creates seismic waves. The seismicity, seismism or seismic activity of an area refers to the frequency, type and size of earthquakes experienced over a period of time...

 that struck the nearby community of Rocky Mountain House

Rocky Mountain House, Alberta

Rocky Mountain House is a town in west-central Alberta, Canada, approximately west of the City of Red Deer. It is located at the confluence of the Clearwater and North Saskatchewan Rivers, and at the crossroads of Highway 22 and Highway 11 .- History :The town has a long history dating to the...

 on October 19, 1996. It was strongly felt 25 km (15.5 mi) southwest of Rocky Mountain House close to the Strachan gas plant. Even though the earthquake reached V-IV on the Mercalli intensity scale

Mercalli intensity scale

The Mercalli intensity scale is a seismic scale used for measuring the intensity of an earthquake. It measures the effects of an earthquake, and is distinct from the moment magnitude M_w usually reported for an earthquake , which is a measure of the energy released...

, no damage was reported. However, alarms went off at the Strachan gas plant when workers recognized a strong bang. It was also during this time when many people were awakened by the earthquake.