The Cedar Mountain earthquake of 1932 was one of the largest seismic events in the US state of Nevada. The Ms 7.3 earthquake struck at Cedar Mountain in Western Nevada. Shaking was felt as far as Oregon, Southern California, and the Rocky Mountains area. Nevada is the third most seismically active state in the United States due to ongoing rifting occurring within the North American plate. Extension or thinning of the crust has resulted in numerous faults accommodating strain, at the same time, producing earthquakes.[3] Since the earthquake occurred in a remote part of the state, damage was limited and no deaths were reported.
  Reno Las Vegas  | |
| UTC time | 1932-12-21 06:10:10 |
|---|---|
| ISC event | 906508 |
| USGS-ANSS | ComCat |
| Local date | December 20, 1932 |
| Magnitude | 7.3 Ms[1] |
| Depth | 10.0 km |
| Epicenter | 38°37′52″N 117°54′36″W / 38.631°N 117.910°W |
| Fault | Central Nevada Seismic Belt, Walker Lane Seismic Zone |
| Type | Strike-slip (dextral) |
| Areas affected | Nevada, United States |
| Total damage | Limited |
| Max. intensity | MMI X (Extreme)[2] |
| Casualties | at least 1 injured |
Tectonic setting
editWestern Nevada lies along the edge of the geologic province known as the Basin and Range. This area of rifting within the North American continent does so in a northwest–southeast direction. Extension of the crust has resulted in a diffuse area of low slip rate faults.[4] This network of predominantly strike-slip and normal faults termed the Central Nevada Seismic Belt (CNSB) occasionally undergoes large "beltlike" earthquake sequences to help accommodate regional stresses with multiple sequences having occurred in the past 13,000 years.[5] This earthquake occurred in the beginning portion of the most recent earthquake sequence, with the 1915 Pleasant Valley earthquake and 1954 Rainbow Mountain-Fairview Peak-Dixie Valley earthquakes also being associated.[5] Further to the west near the border with California, earthquakes become predominantly strike slip along a shear zone known as the Walker Lane which has hosted earthquakes such as the 1872 Owens Valley earthquake.
Earthquake
editThe earthquake occurred along a zone of strike-slip faults creating surface ruptures 60 km (37 mi) long and 6–14 km (3.7–8.7 mi) wide, trending southeast from the epicenter.[6][7] Rupture was distributed across faults spanning three valleys and several mountain fronts including the Stewart-Monte Cristo Valley Fault Zone, and several small, unnamed faults in the Stewart and Gabbs Valleys. Maximum displacement was recorded at 2.7 m (8 ft 10 in), with some dip-slip (normal) offset at 0.5 m (1 ft 8 in).[6][8] During the earthquake, many eyewitness reported lightning bolts and "mysterious lights" in Carson Valley. Shaking reached the maximum of X (Extreme) on the Mercalli intensity scale in Nevada, and overall, was felt for an area size of 850,000 square km.[6][9] This complicated strike-slip earthquake between two mountain ranges was similar to that of the Owens Valley earthquake of 1872.
Impact
editAt the time of the earthquake, the region was uninhabited however, an adobe and stone cabin were destroyed with no injuries. Some damage to mine property and cabins were observed.[10] At Mina, Hawthorne and Luning, the earthquake collapsed chimneys and shattered windows. Chimney damage were also reported in Fallon and the Reese River Valley. In Rhodes, a man suffered a fractured skull when the earthquake threw him against a train engine.[11] The shaking created panic in Carson City, Virginia City, Reno and even in Sacramento, California.[11]
References
edit- ^ International Seismological Centre. Event Bibliography. Thatcham, United Kingdom. [Event 906508].
- ^ "M 6.8 – The 1932 Cedar Mountain Earthquake, Nevada". United States Geological Survey. Retrieved 17 February 2022.
- ^ Price, Jon (2004). "Geology of Nevada" (PDF). University of Nevada, Reno. Retrieved 29 November 2020.
- ^ Price, Jonathan G. (2004). "Geology of Nevada" (PDF). University of Nevada, Reno.
- ^ a b Bell, John W.; Caskey, John S.; Ramelli, Alan R.; Guerrieri, Luca (1 August 1994). "Pattern and Rates of Faulting in the Central Nevada Seismic Belt, and Paleoseismic Evidence for Prior Beltlike Behavior". Bulletin of the Seismological Society of America. 94 (4): 1229–1254. doi:10.1785/012003226. Retrieved 20 August 2022.
- ^ a b c DEPOLO, CRAIG M.; CLARK, DOUGLAS G.; SLEMMONS, D. BURTON; RAMELLI, ALAN R. (20 June 1990). "Historical surface faulting in the Basin and Range province, western North America: implications for fault segmentation". Journal of Structural Geology. 13: 128. CiteSeerX 10.1.1.508.4239.
- ^ Molinari, Mark Philip (December 1984). "Late Cenozoic geology and tectonics of Stewart and Monte Cristo Valleys, west-central Nevada" (PDF). Dissertation. University of Nevada, Reno.
- ^ J.W. Bell; C.M. DePolo; A.R. Ramelli; A. M. Sarna-Wojcicki; C.E. Meyer (1999). "Surface faulting and paleoseismic history of the 1932 Cedar Mountain earthquake area, west-central Nevada, and implications for modern tectonics of the Walker Lane". Geological Society of America Bulletin. 111 (6). United States Geological Survey: 17. Bibcode:1999GSAB..111..791B. doi:10.1130/0016-7606(1999)111<0791:SFAPHO>2.3.CO;2.
- ^ "Significant Earthquake Information NEVADA: CEDAR MOUNTAIN". NOAA NCEI. Retrieved 29 November 2020.
- ^ "Earthquake History of Nevada". CarsonWeather.com. Retrieved 29 November 2020.
- ^ a b "Nevada's Earthquake History" (PDF). shakeout.org. Retrieved 29 November 2020.
Further reading
edit- Gianella, Vincent P.; Callaghan, Eugene (1934), "The Earthquake of December 20, 1932, at Cedar Mountain, Nevada and Its Bearing on the Genesis of Basin Range Structure", The Journal of Geology, 42 (1): 1–22, Bibcode:1934JG.....42....1G, doi:10.1086/624127, JSTOR 30055955, S2CID 129867143