The intensity of an earthquake can be measured by the Modified Mercalli Intensity scale using a I through XII, with I denoting not felt, and XII total destruction. The values will differ based on the distance to the earthquake, with the highest intensities being around the epicentral area. Data are gathered from individuals who have experienced the quake, and an intensity value will be given to their location.
The following summary includes earthquakes centered in Utah with maximum intensity VII or greater with the exception of Springdale and Randolph.
Ogden 1894 (VI – VII)
On July 18, 1894 walls cracked and dishes were shaken from tables.
Santaquin and Goshen 1900 (VI – VII)
On August 1, near Santaquin, an adobe house was split in two and people were thrown from their beds. A chimney was damaged, dishes were broken, and some plaster fell at Goshen.
Parowan to Richfield 1901 (VIII)
On November 13 a strong earthquake caused brick buildings and many chimneys to be damaged. Earth cracks with the ejection of water and sand were reported; in addition, some creeks increased their flow. The total felt area covered about 129,500 square kilometers. Aftershocks continued for several weeks.
Pine Valley, St. George, and Santa Clara 1902 (VII)
Considerable damage resulted at Pine Valley, St. George, and Santa Clara from an earthquake on November 17, 1902. Chimneys were destroyed at Pine Valley and Santa Clara; additional damage occurred at Pinto and Toquerville.
Garland and Tremonton 1909 (VII)
A series of 30 to 60 earthquakes were reported in the vicinity of Garland and Tremonton between October and December 1909. Some of the shocks were strong enough to throw down chimneys. Two tremors about 30 minutes apart were reported felt over a wide area of northwestern Utah on October 5, 1909.
Salt Lake City 1910 (VII)
A May 22 earthquake damaged many chimneys at Salt Lake City and several old buildings.
Ogden and Farmington 1914 (VII)
On May 13 windows were broken and chimneys thrown down at Ogden; near panic was reported at Central Junior High School. Dishes rattled and furniture moved at Farmington. The shock was felt for an area covering about 20,700 square kilometers.
Elsinore, Monroe, and Richfield 1921 (VIII)
Two strong earthquakes about 12 hours apart shook Elsinore, Monroe, and Richfield on September 29. The first shock, at 7:12 a.m., lasted 7 to 10 seconds and threw down scores of chimneys, tore plaster from ceilings, and fractured walls at Elsinore. In addition, gables of houses were thrown out and the foundation of a new school sank one foot, leaving gaps between the walls and the roof.
Another shock occurred at 7:30 p.m. on the same day. On October 1, there was yet another strong tremor causing further damage at Elsinore. A number of brick and stone buildings were rendered uninhabitable. The Monroe City Hall, built of rock, was severely damaged.
Kosmo 1934 (VIII)
On March 12, at 8:06 a.m., an earthquake originating near Kosmo, on the north shore of Great Salt Lake, affected an area of about 440,000 square kilometers, including much of northern Utah and parts of Idaho, Montana, Nevada, and Wyoming. This tremor could have caused great damage in a densely populated area. There was moderate damage over a broad area, including Salt Lake City, where plaster fell. All chimneys fell in Kosmo and Monument; fissures, holes, cracks, and springs appeared in connection with a belt of fractures at least 8 kilometers long.
Franklin, Lewiston, Logan, Preston, and Richmond 1962 (VII)
An August 30 earthquake cause significant damage at Franklin, Lewiston, Logan, Preston, and Richmond. Cache County was designated a disaster region by the Small Business Administration. The greatest damage occurred at Richmond where at least nine houses were declared unsafe for occupancy, one church was damaged beyond repair, numerous houses lost walls, and 75 percent of the older brick chimneys fell. Four schools in Cache County were seriously damaged. The shock was felt over an area of approximately 168,000 square kilometers.
Marysvale, Koosharem, and Joseph 1967 (VII)
On October 4 an earthquake caused ceilings and walls to crack in numerous houses in Marysvale. At Koosharem, chimneys and plaster cracked. Chimneys were partially knocked down at Joseph. The tremor was felt over 38,800 square kilometers of southern Utah.
Springdale 1992 (VI)
The September 2 earthquake triggered a large landslide which destroyed three houses at Springdale. Felt throughout much of southwestern Utah, northwestern Arizona and southeastern Nevada as far north as Richfield, Utah and as far south as Flagstaff, Arizona. Felt west as far as Caliente and Pioche, Nevada and southwest to the Las Vegas, Nevada area.
Randolph 2010 (VI)
An earthquake on April 15 near Randolph shook buildings and caused pictures and other items to rattle and crash to the floor.
Source: Utah Earthquake History