Earth Quake Facts

Most of Utah’s Populated Area Lies Within an Active Earthquake Belt

Historical quakes of about magnitude (M) 5.5 and larger in the Utah region*
1884	M 6	Bear Lake Valley
1887	M 5.5	Kanab
1900	M 5.5	Eureka
1901	M 6.5	Richfield
1902	M 6	Pine Valley
1909	M 6	Hansel Valley
1910	M5.5	Salt Lake City
1914	M 5.5	Ogden
1921	M 6	Elsinore (two events)
1934	M 6.6	Hansel Valley
1959	M 5.7	Utah-Arizona Border
1962	M 5.7	Richmond
1966	M 6.0	Utah-Nevada Border
1975	M 6.0	Utah-Idaho Border
1992	M 5.9	St. George
*sizes of shocks before 1934 are approximate

Average Frequency of Earthquakes* in the...
Wasatch Front		Entire Utah Region
Magnitude	Frequency		Frequency
≥ 3.0	3 per year		8 per year
≥ 4.0	1 every 2 years		1 per year
≥ 5.0	1 every 10 years		1 every 5 years
≥ 5.5	1 every 20 years		1 every 10 years
≥ 6.0	1 every 50 years		1 every 30 years
≥ 7.0	[based on geologic evidence, time scale of hundreds of years - page 7]
≥ Greater than or equal to * Based on historical record and instrumental monitoring (largest historical shock was M 6.6 in 1934); excludes foreshocks, aftershocks, and human-triggered seismic events
Source: University of Utah Seismograph Stations

What should you do when the shaking starts?

DROP, COVER, AND HOLD ON. If you • are not near a desk or table, drop to the floor against an interior wall and protect your head and neck with your arms.
Avoid exterior walls, windows, • hanging objects, mirrors, tall furniture, large appliances, and cabinets filled with heavy objects.
Do not go outside until well after the • shaking stops!