Mine blasting likely behind minor quakes near Princeton

PENTICTON – A cluster of earthquake-like events occurring around Princeton have a man-made explanation, says a Natural Resources Canada seismologist.

Trevor Allen, Seismologist for Natural Resources Canada, says very few naturally occurring earthquakes have been recorded within 50 kilometres of Penticton. He says most of the earth tremors appear to be related to blasting at the Copper Mountain Mine located just south west of Princeton.

Approximately 40 of the mine blasts were large enough to be recorded by multiple seismograph stations last year.

Allen says those tremors are generally in the 1.5 to 2 magnitude range. He can’t say whether all the blasts that take place at the mine are recordable events.

“We sometimes get reports of earth movement in the area of the mine southwest of Princeton,” Allen says, “Those reports often correlate with the timings of blasts at the mine.”

Copper Mountain Mine reopened in the summer of 2011. The mine is located 20 km south of Princeton and has an expected life span of 17 years, producing copper with gold and silver secondary metals. Present work will see three major open pits on the property developed into a single “super pit."

A search of the earthquake database for earthquakes and mine blasts for the period Copper Mountain Mine has been open (July, 2011 – February, 2016) reveals approximately 160 events occurring between 10 to 15 km south or southwest of Princeton.

A search of the database for a corresponding five year period prior to the mine opening, between 2006-2011 does not indicate a similar cluster of similar sized earthquakes occurring near Princeton during that time frame.

Earthquakes Canada does caution, however, information for mining-related event and blasts may not be complete.

Allen says earthquakes can occur at any time virtually anywhere in the province, adding the best way for residents to be prepared is through the implementation of strong building codes.

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