Google Earth Tour: The Faults of Flagstaff, Arizona
This 4-minute Google Earth flight examines the Lake Mary and Cataract Creek Fault systems near Flagstaff, Arizona. The 25-mile-long Lake Mary fault extends from Mormon Lake north to the city boundary of Flagstaff. It comprises dozens of active fault strands. If the entire fault ruptured, it would produce a M7 earthquake that would damage and crumble unreinforced masonry buildings in downtown Flagstaff.
To view the video: https://youtu.be/2ihdKoFIiss
Rupture along the length of the fault is unlikely. But according to Dr. Dave Brumbaugh (Northern Arizona University Professor Emeritus), rupture of just one or two fault strands could produce a M6 to M6.3 earthquake.
Forty-five miles north-northwest of Flagstaff, lies the Cataract Creek fault system. This broad fault system includes dozens of fault strands with an areal extent of 20 miles north-northwest and 10 miles wide. Three M6.0 events that struck Flagstaff in 1906 and 1912 are thought to have originated here. In 1993, a M5.3 earthquake on the Cataract Creek fault rocked Flagstaff and the nearby community of Valle.
Fault symbolization of Quaternary faults: Sources: Arizona Geological Survey & U.S. Geological Survey
- Green line segments – young active faults.
- Blue line segments – older active faults.
- Black line segments – faults of indeterminate age.
Let us know what you think of the tour.