Earthquakes in Alberta (Induced Seismicity)

Project Goal

Alberta Geological Survey is developing a provincial database to include all sources of seismic data. We will maintain these data to assist in the understanding of the relationship between human activities and micro-seismicity in Alberta. The goal of this project is to collect and organize the information from universities, production data and government on a provincial scale.

Project Background

Induced seismicity refers to micro-earthquakes and tremors caused when human activity alters the stresses and strains in the Earth's crust.

Most induced seismicity are of very low magnitude. In many cases, human activity was merely the trigger for an earthquake that would have eventually happened naturally.

Earthquake Facts

A micro-earthquake is less than a magnitude 3 on the Richter scale. Micro-earthquakes are rarely felt, but may be recorded by nearby seismographs.

The frequency of these earthquakes has increased in Alberta since the 1970s (from less than 60 to more than 200 per decade) and has continued throughout the past four decades.

Micro-earthquakes are not hazardous in themselves as they are unlikely to cause damage to buildings or infrastructure. They are, however, of interest for the following two reasons:

1. To document and understand their relationship to oil and gas production to better understand the effects of fluid injection and withdrawal; and
2. To investigate potential links to the small but significant increase in minor earthquakes over the years.

Micro and minor seismicity in Alberta are much less frequent than those in tectonically active regions, such as British Columbia. As a result, monitoring of micro-seismicity is not within the mandate or scope of nationally based organizations, such as Earthquakes Canada, and has not received the attention it requires.

Project Lead:  Virginia Stern

Collaborators
University of Alberta
University of Calgary