The 1901 Richfield earthquake was a magnitude Mw7.0 earthquake that occurred on 13 November 1901 at approximately 9:39 PM MST at Richfield, Utah, United States. If estimations are accurate, it is the largest earthquake ever recorded in Utah.[1]
Earthquake
The earthquake struck at approximately 9:39 PM MST approximately 1.2 miles (1.9 km) south of Richfield, Utah, United States.[2][3] Reports of the length of the quake varied from about one minute to three minutes.[4][5] There were three waves—increasing in power—to the initial quake, and "roaring" or "low rumbling" sounds accompanying the shock waves were reported in Fillmore, Cedar City, and Salt Lake City.[5]
The time of the quake is officially recorded by the Intermountain Seismic Belt Historical Earthquake Project (ISBHEP) as 9:39 PM MST.[2] The USGS report gives an official time as 9:32 PM MST.[3] News reports from the time give times ranging from 9:30 PM MST to 10:45 PM MST.[4][5]
Magnitude and intensity
The quake was recorded by the ISBHEP as a Mw6.5 and an intensity of IX (Violent).[2][6] The official USGS report in their historical earthquakes list stated no magnitude and an intensity of VIII (Severe).[3][7][8] An official report published in 1988 assigned a magnitude of Mw7 and an intensity of IX (Violent).[1]
The quake was felt in an area of 50,000 square miles (130,000 km2), including Cedar City (intensity VI), Oasis, and Fillmore.[3][1] Salt Lake City (with intensity of IV) is considered an "outlying point well outside the boundary of the main felt area."[1]
Surface ruptures up to 300 feet (91 m) in length were reported in Richfield, with water and white sand being ejected from some of the cracks.[1] "Extensive rockslides" were reported between Beaver and Marysvale, especially in the canyons.[1]
Damage in Beaver included Beaver Woolen Mills, with an estimated US$4,000 in severe structural damage (approximately US$121,000 in 2020).[5][9] The roof of the Beaver Countycourthouse was crushed by chimneys collapsing onto it, and the walls of the building were cracked in over 25 places. Additional reports of lesser damage include a saloon, several merchant buildings, schools and related buildings, and a church building. Merchandise in several stores was also damaged.[5]
Minor damage was reported as far away as Salt Lake City, where several landslides were reported in Little Cottonwood, Big Cottonwood, and Bullion Canyon.[1] The landslides almost completely blocked the roads.[1] Surface ruptures and increased river flow were also reported.[1]
^"Earthquake Summary"(PDF). University of Utah. Archived(PDF) from the original on 21 April 2020. Retrieved 1 May 2020. For historical earthquake data where there was no instrumental recording of the shock, magnitude is estimated from the size of the felt area (see below). In such cases, the magnitudes are listed as a whole number followed by a ± or a fraction (e.g., 1/2) rather than a decimal (e.g., 0.5).
