1980 Eureka earthquake

1980 Eureka earthquake
1980 Eureka earthquake is located in USA West
Salem
Salem
Riley
Riley
Lake City
Lake City
Fallon
Fallon
Chowchilla
Chowchilla
1980 Eureka earthquake
UTC time1980-11-08 10:27:34
ISC event635132
USGS-ANSSComCat
Local dateNovember 8, 1980 (1980-11-08)
Local time02:27:34 PST
Magnitude7.3 Mw[1]
Depth6.2 mi (10 km)[1]
Epicenter41°08′N 124°26′W / 41.13°N 124.44°W / 41.13; -124.44[1]
TypeStrike-slip[2]
Areas affectedNorth Coast (California)
United States
Total damage$2–2.75 million[2][3]
Max. intensityMMI VII (Very strong)[3]
Peak acceleration0.15–0.25 g[4]
LandslidesYes
CasualtiesSix injured[3]

The 1980 Eureka earthquake (also known as the Gorda Basin earthquake) occurred on November 8 at 02:27:34 local time along the northern coastal area of California in the United States. With a moment magnitude of 7.3 and a maximum Mercalli intensity of VII (Very strong), this strike-slip earthquake was the largest to occur in California in 28 years. Although damage was considered light, several loss estimates equaled or exceeded $2 million, and six injuries resulted when two vehicles came down with the partial collapse of a highway overpass on US 101 in Fields Landing. The north coast of California experiences frequent plate boundary earthquakes near the Mendocino Triple Junction and intraplate events also occur within the Gorda plate.

Due to the regional seismic risk, the nuclear portion of the Humboldt Bay Nuclear Power Plant was shut down in the 1970s. No substantial damage occurred to the two fossil-fuel units that were still operational at the facility. Several types of sensors were installed at the site to capture strong motion data in this seismically active area, but the majority of records from the event were considered unreliable due to faulty equipment or inadequate maintenance. Only one piece of equipment at the facility provided data by which an estimate of the peak ground acceleration could be made.

  1. ^ a b c Cite error: The named reference ISC-GEM was invoked but never defined (see the help page).
  2. ^ a b Cite error: The named reference PAGER-CAT was invoked but never defined (see the help page).
  3. ^ a b c Cite error: The named reference Stover was invoked but never defined (see the help page).
  4. ^ Cite error: The named reference nrc was invoked but never defined (see the help page).