Date: Jan 31, 1922
Location: West of Eureka
The Mendocino fault off the northern California coast is the primary cause of the January 31st 1922 west of Eureka earthquake. People within San Francisco, Oregon and Eugene felt the earthquakes effects. And in 1992, another series of earthquakes that had magnitudes above 6.5 occurred in the same region, lasting for 18 hours. Later in the year 2010, another earthquake of 6.5 magnitudes struck the coastal Eureka and destroyed window in addition to snapping power lines.
Earthquakes have been occurring in California from time to time mainly because this state is situated on San Andreas Fault. The fault cuts across the state and also forms a tectonic plate boundary between the North American Plate and the Pacific. Each and every year, people living in the state experience thousands of small earthquakes – some of them are very small to be felt. The state's complex landscape is attributed to a network of faults which run through it. The first recorded earthquake in the state occurred in the year 1769. The Portola expedition felt this earthquake around 30 miles Southeast of Los Angeles.
The major causes of earthquakes in California
There are numerous active faults throughout California and they are known to be the main causes of earthquakes. San Jacinto Fault Zone is the most active fault and it is situated in Southern California. In the most recent history, this fault has produced many events on a regular basis. Another very active fault is the Mendocino Triple Junction situated offshore of the Northern California. It has produced very many earthquakes with magnitudes above 6.
The northern California is subject to many earthquakes resulting from Cascadia subduction zone which extends north from Mendocino. One of these earthquakes is the 1700 Cascadia earthquake that had a magnitude of around 9. Parkfield town in Central California is situated on a San Andreas Fault section which produces earthquakes around M6 each and every 20-30 years. In 1857, 1881, 1901, 1922, 1934, 1966 and 2004 the area experienced earthquakes.
The largest ever recorded earthquake in this state was in the year 1857 – the Fort Tejon Earthquake – which had a magnitude of 7.9. The earthquake ruptured San Andreas Fault from Parkfield to Wrightwood – a distance around 350 KM (225 miles). The 1906 San Francisco earthquake is still the most destructive earthquake ever recorded in the region – around 3000 individuals perished in this earthquake and fires which followed. In 1906, an earthquake which happened ruptured the San Andreas Fault northern segment for 477 Km (296 miles) from Cape Mendocino in north to San Juan Bautista.
The most recent earthquakes in the region include the 1989 Loma Prieta earthquake which had a magnitude of 6.9. It highly affected the San Francisco Bay Area. The other is the Northridge earthquake that registered a 6.7 magnitude and affected the Greater Los Angeles Area – this earthquake also caused widespread deaths and damages within this area.
Other earthquakes that have affected West of Eureka
The west of Eureka area experiences earthquakes from time to time. On 9th January 2010, an earthquake of 5.5 magnitude occurred around 53 km (33 miles) offshore of Eureka. And after two seconds this earthquake turned into a violent jumper making objects to fly. The vertical shocks caused broken windows in commercial properties, overturned shelves in stores and damages to various architectural details on several historic buildings. The local hospitals mainly treated minor related injuries while there was an electrical power outage on a very large area. Moreover, various gas leaks happened even though no fire resulted.
This was the most recent earthquake since April 25 1992 sequence. On February 2010, a magnitude 5.9 earthquake followed. This earthquake occurred at around 12:20 pm (the local time) around 65 km (35 miles) Petrolia community 80 Km (50 miles) west of Eureka. People within a radius of 150 miles (240 km) felt the earthquake.