1915 Pleasant Valley earthquake
The Tobin Range on the east side of the valley showing the fault scarp (marked by the white line)
|Date||06:53:21 on October 3 UTC |
|Magnitude||6.8 Mw |
|Depth||10 km (6.2 mi) |
|Areas affected||Pershing County, Nevada
|Total damage||Limited |
|Max. intensity||X (Extreme) |
The 1915 Pleasant Valley earthquake occurred at 22:53:21 on October 2 in north-central Nevada. With a moment magnitude of 6.8 and a maximum Mercalli intensity of X (Extreme), it was the strongest earthquake ever recorded in the state.
The earthquake remains as one of the best examples ever for evidence of creating spectacular fault scarps along the west side of the Tobin Range. It produced four scarps, with a total length of 59 kilometers (37 mi), and re-ruptured Holocene scarps located at the bottom of the base of the mountain blocks. Among the scarps, the average vertical displacement among the affected areas was 2 meters (6 ft 7 in), and the maximum displacement of 5.8 meters (19 ft) occurred near the old Pierce School site on Buskee Creek Canyon.
The rupture originated along an unnamed fault somewhere in the eastern side of Pleasant Valley, in north-central Nevada. The epicentral region was mostly uninhabited, so there was little property damage considering the very large magnitude.
The earthquake's damage was confined to within 50 miles (80 km) of the epicenter. Damage in Kennedy destroyed two adobe houses, collapsed several mine tunnels, and cracked concrete mine foundations. Winnemucca experienced damage to adobe buildings as well, and several multistory brick buildings lost coping and upper wall parts. Many chimneys were destroyed if they were above roof lines. Water tanks were knocked over in Battle Mountain, Kodiak, Lovelock, and Parran. Several ranches reported damage, all by the southern end of Pleasant Valley. More adobe houses were knocked down by the shaking; a masonry chicken house and a hog pen were destroyed; and houses were displaced from their foundations.
- ISC (2015), ISC-GEM Global Instrumental Earthquake Catalogue (1900–2009), Version 2.0, International Seismological Centre
- National Geophysical Data Center / World Data Service (NGDC/WDS), Significant Earthquake Database, National Geophysical Data Center, NOAA, doi:10.7289/V5TD9V7K
- Stover, C.W.; Coffman, J.L. (1993), Seismicity of the United States, 1568–1989 (Revised), U.S. Geological Survey Professional Paper 1527, United States Government Printing Office, pp. 284, 291
- "Earthquake History:OCTOBER 3, 1915 (M=7.3)". Wallace. 1984. Archived from the original on November 1, 2006. Retrieved 2008-11-27.
- Mt. Tobin, Nev 15 minute topographic quadrangle, 1961, USGS
- USGS contributors (2008-07-16). "Historic Earthquakes: Pleasant Valley, Nevada". USGS. Archived from the original on 11 November 2008. Retrieved 2008-11-25.
- Gunn, Angus M. (2008). Encyclopedia of Disasters. Greenwood Publishing Group. p. 260.
- Jones, J. C. (1915), "The pleasant valley, Nevada, earthquake of October 2, 1915", Bulletin of the Seismological Society of America, Seismological Society of America, 5 (4): 190–205