Researchers at Northern Arizona University’s Arizona Earthquake Information Center report that a swarm of small earthquakes occurred June 21-26 seven miles south of Flagstaff near the Lake Mary reservoir.
David Brumbaugh, professor of geology and director of the center, said the earthquakes ranged from 2.0 to 2.7 in magnitude. He noted that a similar swarm last occurred in the same area on Oct. 5-7, 1979.
According to Brumbaugh, the swarms indicate that the Anderson Mesa fault zone, which at 40 kilometers is one of the longest in the Flagstaff area, is still active.
The earthquake information center, located in the geology building on the Flagstaff campus, collects and distributes information on Arizona earthquakes and conducts research based on that data.