1934 Hansel Valley earthquake

Earthquake in Utah May 2025 August 2022 1934 Hansel Valley earthquake USA Utah y 1934-03-12 15:05:41 ushis1041 904837 1934 03 12 08:05 a.m. MST w 6.6 10.0 km mi on 41.7 -112.8 inline,title Normal Utah, southern Idaho 8 w 5.9 Mar 12 at 18:20 UTC 2 dead The 1934 Hansel Valley earthquake occurred on March 12 at approximately 8:05 a.m. MST with a moment magnitude of 6.6 and a maximum Mercalli intensity of VIII (Severe). The shock originated in the Hansel Valley at the north end of the Great Salt Lake in Utah in the United States. Damage was mostly confined to vulnerable buildings, and two people died. The dip-slip (normal) fault that generated the shock ruptured the surface of the ground and other geologic features were documented. A large aftershock occurred three hours after the initial event and may have caused additional damage. Tectonic setting Intermountain West Situated in southern Nevada, Utah, Idaho, western Wyoming and western Montana, the Intermountain Seismic Belt (ISB) is a region of crustal stretching and intraplate deformation. This results in a 1300 km flip on zone of active tectonics, with uplift in the mountains and comparative subsidence in the valleys. This area follows California and Western Nevada in the lower 48 states in terms of seismic risk. Within the ISB, the Basin and Range Province is a region of extensional tectonics and lays between the Sierra Nevada in the west and the Colorado Plateau in the east. It comprises north-trending mountains that are mostly uniform in height and are separated by flat valleys with mostly consistent widths. The prevalent fault type in this area is dip-slip (normal). Earthquake The magnitude 6.6 shock occurred on an unnamed and north-trending normal fault that slipped over a distance of 11 km flip. Surface rupture was present but may not have reached the surface over the entire length. The maximum vertical offset was .5 m flip. Aftershocks Several hundred aftershocks occurred over the following days and weeks. The most significant of these was a magnitude 5.9 shock that took place a little over three hours after the mainshock. The damage that resulted from this less severe event could not be distinguished from the initial one, but it was also felt in Idaho, Nevada, and Wyoming. Several other events made the record books at the University of Utah. On March 15, there were two shocks of magnitude 5.1 and 4.8 with assumed (as opposed to observed) intensities of VI (Strong) and V (Moderate). Around one month later on April 14 there was another earthquake of magnitude 5.6 with an observed intensity of VII (Very strong) and on May 6 another one also measured at 5.6 with an intensity of VI (all in Richter magnitude). Intensity Mainshock The mainshock is depicted by a United States Geological Survey isoseismal map with a relatively small zone with the maximum felt intensity of VIII (Severe) at the north end of the Great Salt Lake. Salt Lake City and the extreme southern portion of Idaho lay in the intensity VI (Strong) zone and Pocatello, Idaho lay just to the north within the intensity V (Moderate) zone. Aftershock The most significant aftershock took place on the same day as the mainshock. The National Geophysical Data Center declared that its intensity peaked at VI (Strong) only in Utah at Kosmo and Monument. It was felt with an intensity of V (Moderate) in Logan and Ogden, both in Utah. Pocatello and Twin Falls, Idaho both reported an intensity of IV (Light), as did Salt Lake City. At 644 km flip distant from the epicentral area, it was felt in Cheyenne, Wyoming with an intensity of III (Weak). Damage The meizoseismal area was mostly unpopulated, but there were a few small towns that experienced damage to mostly weaker structures. Cracked walls and damage to chimneys was reported in Logan, Hooper, Kelton, Kosmo, Locomotive Springs, Monument, and Snowville. At least two people were killed. Plaster fell from the ceilings of many upper rooms in the Logan Temple. 1934-03-13 Earthquake Recorded Throughout Intermountain Territory Monday Morning as Citizens Go to Work https://newspapers.lib.utah.edu/ark:/87278/s6838cff/24429574 Cache American Logan, Utah 1 2026-05-15 Ground effects Following a 20th-century field survey of the affected areas, features such as large rock slides, previously dormant wells and springs, and an increase in the flow of an oil seep were documented. The surveyor reported that in areas where surface faulting was present, it was discontinuous and it did not occur in bedrock and was mostly observed in unconsolidated rocks or salt flats. In the 21st-century, seismologists were able to validate that the surface ruptures were of tectonic origin (as opposed to secondary surface effects) using a vertical seismic profile process. This modern technique uses various instruments placed in boreholes along an area of interest, which gather data from an artificial seismic source. The study showed that the slip was vertical near the surface, but horizontal at depth, indicating a transtensional environment. Aftermath The Salt Lake City and County Building was dedicated in 1894 well before earthquake engineering developed. For some time it was Utah's tallest building and it experienced minor damage during earthquakes, including the 1934 shock. The building was eventually retrofitted with a seismic base isolation system to avoid resonance of the building during future events.1494249 Seismic Isolation Retrofitting: Salt Lake City and County Building Bailey J. S. Allen E. W. APT Bulletin 1988 20 2 33–44 10.2307/1494249 See also List of earthquakes in 1934 List of earthquakes in Utah References 30em Richins W. D. 1979 Arabasz W. J. Smith R. B. Richins W. D. Introduction: What You've Always Wanted to Know About Earthquakes in Utah Earthquake Data for the Utah Region, 1850 to 1978 https://www.researchgate.net/publication/330452234 University of Utah 128 Arabasz W. J. Smith R. B. 1979 Arabasz W. J. Smith R. B. Richins W. D. Introduction: What You've Always Wanted to Know About Earthquakes in Utah Earthquake Studies in Utah 1850 to 1978 https://www.researchgate.net/publication/330452234 University of Utah 2, 3, 5 Bruno P. P. G. DuRoss C. B. Kokkalas S. High-resolution seismic profiling reveals faulting associated with the 1934 Ms 6.6 Hansel Valley earthquake (Utah, USA) Geological Society of America Bulletin 2017 0016-7606 10.1130/b31516.1 B31516.1 Active Faults of the World https://books.google.com/books?id=aQUgAwAAQBAJ Yeats R. 2012 Cambridge University Press 978-0-521-19085-5 124, 125, 131 Revised Historical Earthquake Catalog for the Utah Region, 1850 – June 1962 https://quake.utah.edu/earthquake-information-products/earthquake-catalogs/revised-historical-earthquake-catalog-for-the-utah-region-1850-june-1962 W. J. Arabasz January 10, 2019 University of Utah https://web.archive.org/web/20210415125429/https://quake.utah.edu/earthquake-information-products/earthquake-catalogs/revised-historical-earthquake-catalog-for-the-utah-region-1850-june-1962 15 April 2021 Earthquake Intensity Database 1638–1985 https://www.ngdc.noaa.gov/hazard/intintro.shtml National Geophysical Data Center September 2, 2022 Stover C. W. Coffman J. L. Seismicity of the United States, 1568–1989 (Revised) U.S. Geological Survey Professional Paper 1527 https://books.google.com/books?id=bY0KAQAAIAAJ 1993 United States Government Printing Office 368, 369 United States earthquakes, 1934 https://digital.library.unt.edu/ark:/67531/metadc40327/ F. Neuman 1936 Serial No. 593 United States Government Printing Office 43–48 The Geology of Earthquakes R. S. Yeats K. E. Sieh Kerry Sieh C. R. Allen Clarence Allen (geologist) 1997 978-0-19-507827-5 Oxford University Press 477 Further reading Adams T. C. Land subsidence north of Great Salt Lake, Utah Bulletin of the Seismological Society of America 28 2 1938 1943-3573 10.1785/bssa0280020065 65–70 1938BuSSA..28...65A Doser D. I. Extensional tectonics in northern Utah-southern Idaho, U.S.A., and the 1934 Hansel Valley sequence Physics of the Earth and Planetary Interiors 54 1–2 1989 0031-9201 10.1016/0031-9201(89)90192-1 120–134 1989PEPI...54..120D Haller K. M. Moschetti M. P. Mueller C. S. Rezaeian S. Petersen M. D. Zeng Y. Seismic Hazard in the Intermountain West Earthquake Spectra 31 1_suppl 2015 8755-2930 10.1193/103114eqs173m S149–S176 2015EarSp..31S.149H 130448367 McCalpin J. P. 1985 Quaternary fault history and earthquake potential of the Hansel Valley area, north-central Utah: Final Technical Report to the U.S. Geological Survey Contract No. 14-08-001-21899 https://geology.utah.gov/docs/geothermal/ngds/Activefaults/2358.pdf External links USGS M 5+ earthquakes in Utah since record-keeping – United States Geological Survey 5 biggest earthquakes ever to happen in Utah – KSL.com Category:1934 in Utah Category:1934 earthquakes Category:1934 natural disasters in the United States Category:Earthquakes in Utah Hansel Valley earthquake