Geohazards Program

Natural Occurring Geological Hazards

Publications

Geohazard Articles, Posters & Presentations

Projects

Last modified:
February 25, 2015

Earthquakes and Seismicity in Alberta

Alberta is a prairie province bordering the eastern flank of the Rocky Mountains. Its geographic location is characterized by a transition from a relatively low-seismicity intraplate regime to a more active foreland belt. It is also an area of active energy resource development, including coal, natural gas, conventional oil, and unconventional hydrocarbon resources. The federal government has monitored earthquakes in Canada since the late 1800s, and by 1950 had the capacity to detect earthquakes of magnitude 6 and larger throughout Canada. While there has been no recorded evidence of any major destructive earthquake occurring in Alberta to date, there has been hundreds of micro to moderate earthquakes from 1950 to the present. The magnitudes of seismic events in Alberta tend to be between 0 (micro) and 3 (minor) ML; moderate earthquakes with a magnitude greater than 4 ML are rarer (see table below for a classification of earthquake sizes based on magnitude). Although there appears to be little threat from major earthquakes, it is important to understand the seismicity patterns within Alberta. There is evidence that in some cases earthquakes worldwide have been related to hydrocarbon production, such as fluid extraction, enhanced recovery methods, or wastewater injection.

Table 1.  Magnitudes of Earthquakes

Magnitude (M) Earthquake Class Effects of Earthquakes Recording of Earthquakes
5 to 5.9 Moderate Felt, may result in damage to buildings and other structures Readily recorded on distant near-surface seismographs
4 to 4.9 Light Felt, may result in minor damage Readily recorded on regional near-surface seismographs
3 to 3.9 Minor Often felt Readily recorded on regional near-surface seismographs
0 to 2.9 Very minor Earthquakes below 2.5 are rarely felt Recorded on local near-surface seismographs
Less than 0 Micro Not felt Recorded only on nearby down-hole geophones used for microseismic monitoring

Source - http://www.geo.mtu.edu/UPSeis/magnitude.html