The 1980 Livermore earthquake occurred on January 24 at 11:00 PST in California. The epicenter of the 5.8 Mw earthquake was a hilly area 12 km (7.5 mi) southeast of Mount Diablo and north of Livermore Valley. The earthquake had a maximum Modified Mercalli intensity of VII (Very strong). Forty four people were injured and damage across the San Francisco Bay Area totaled $11.5 million, with the majority inflicted at the Lawrence Livermore National Laboratory.
  | |
| UTC time | 1980-01-24 18:00 |
|---|---|
| ISC event | 653190 |
| USGS-ANSS | ComCat |
| Local date | January 24, 1980 |
| Local time | 11:00 PST |
| Magnitude | 5.8 Mw[1] |
| Depth | 10 km (6.2 mi)[1] |
| Epicenter | 37°44′35″N 121°49′30″W / 37.743°N 121.825°W[1] |
| Fault | Greenville Fault |
| Type | Strike-slip |
| Areas affected | East Bay Northern California United States |
| Total damage | $11.5 million |
| Max. intensity | MMI VII (Very strong)[2] |
| Casualties | 44 injured |
Earthquake
editThe mainshock was preceded by a 2.7 ML foreshock 1.5 minutes prior. In the first six says after the mainshock, 59 aftershocks were recorded measuring ≥ 2.5 ML .[3] On January 26, a Mw 5.3 aftershock occurred with an epicenter 14 km (8.7 mi) southeast of the mainshock. Six hundred aftershocks were recorded in the 33 days after the mainshock. An analysis of P-wave indicate the fault plane solution was right-lateral strike-slip faulting.[4]
Faulting
editSurface faulting consisting of discontinued and small offsets occurred along the Greenville and Las Positas faults. At least 4.2 km (2.6 mi) of rupture occurred on the Greenville Fault, but it may have extended south to Interstate Highway 580, giving a possible total length of 6.2 km (3.9 mi). Surface faulting was sparse along the rupture. A maximum right-lateral offset of 25 mm (0.98 in) and vertical offset of 50 mm (2.0 in) was recorded. A 0.5 km (0.31 mi) rupture was located 0.12–0.25 km (0.075–0.155 mi) east of the main rupture, and 25 m (82 ft) away from another known fault. The secondary break produced 20 cm (7.9 in) of right-lateral offset, and 40 mm (1.6 in) of extension. Offset was also recorded along at least 1.1 km (0.68 mi) of the Las Positas Fault Zone. These consisted of small left-lateral offsets.[5]
Damage
editDamage to property was nonstructural—consisting of fallen ceiling tiles, detached bricks from chimneys, ruptured gas and water lines, shattered windows, and mobile homes displaced from their foundations. At a ranch north of Livermore, along Vasco Road, two brick-and-stone fireplaces were fractured and offset from their walls. Along Interstate 580 and Greenville Road, a concrete pavement sunk 30 cm (12 in), and the a concrete abutment fractured and spalled. Forty four people were injured. Damage at the Lawrence Livermore National Laboratory was estimated at $10 million.[6]
The January 26 aftershock caused six additional injuries in Livermore from glass and falling debris. Fifty homes sustained minor damage in Tassajara. A fireplace was damaged, walls and concrete fractured, walls detached from ceilings, windows broke and a chimney collapsed. In Danville, a brick chimney and fireplace were damaged, stone wall was destroyed, and walls, patios, sidewalks and ceilings cracked. Several other towns reported slight damage.[6]
See also
editReferences
edit- ^ a b c ISC (19 January 2015), ISC-GEM Global Instrumental Earthquake Catalogue (1900–2009), Version 2.0, International Seismological Centre
- ^ National Geophysical Data Center / World Data Service (NGDC/WDS) (1972), "Significant Earthquake Information", NCEI/WDS Global Significant Earthquake Database (Data Set), National Geophysical Data Center, NOAA, doi:10.7289/V5TD9V7K, retrieved August 2, 2022
- ^ Bolt, B. A.; McEvilly, T. V.; Uhrhammer, R. A. (1981). "The Livermore Valley, California, sequence of January 1980". Bulletin of the Seismological Society of America. 71 (2): 451–463. Bibcode:1981BuSSA..71..451B. doi:10.1785/BSSA0710020451.
- ^ Cockerham, R. S.; Lester, F. W.; Ellsworth, W. L. (1980). "A preliminary report on the Livermore Valley earthquake sequence January 24 – February 26, 1980" (PDF). Open-File Report (Report). Open-File Report 80-714. p. 45. doi:10.3133/ofr80714.
- ^ Bonilla, M.G.; Lienkaemper, J.J.; Tinsley, J.C. (1980). Surface Faulting near Livermore, California Associated with the January 1980 Earthquakes (Report). Survey Open-File Report 80–523. U.S. Geological. p. 32.
- ^ a b 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. 166–167