MAJOR EARTHQUAKE IN CALIFORNIA

Major Earthquake in California

Major Earthquake in California

Northridge Earthquake

TIME: January 17, 1994 / 4:30:55 am PSTLOCATION: 20 miles west-northwest of Los Angeles MAGNITUDE: 6.7

At 4:30 am, on January 17, 1994, residents of the greater Los Angeles area were rudely awakened by the strong shaking of the Northridge earthquake. This was the first earthquake to strike directly under an urban area of the United States since the 1933 Long Beach earthquake. (Prentice, 3)

The earthquake occurred on a blind thrust fault, and produced the strongest ground motions ever instrumentally recorded in an urban setting in North America. Damage was wide-spread, sections of major freeways collapsed, parking structures and office buildings collapsed, and numerous apartment buildings suffered irreparable damage. Damage to wood-frame apartment houses was very widespread in the San Fernando Valley and Santa Monica areas, especially to structures with "soft" first floor or lower-level parking garages. The high accelerations, both vertical and horizontal, lifted structures off of their foundations and/or shifted walls laterally. (Prentice, 3)

Loma Prieta Earthquake

TIME: October 17, 1989 / 5:04 pm PSTLOCATION: 10 miles northeast of the city of Santa Cruz, California,MAGNITUDE: 7.1

The Loma Prieta earthquake occurred in the greater San Francisco Bay Area in California. It is popularly nicknamed the World Series Quake because it occurred during the World Series, which happened to match up the Bay Area's two Major League Baseball teams. The earthquake lasted for 15 seconds Portion of the Cypress Street Viaduct, Interstate 880, in Oakland collapsed. (Prentice, 3)This was a major earthquake which caused severe damage as far as 70 miles away; most notably in San Francisco, Oakland, the San Francisco Peninsula, and in areas closer to the epicenter in the communities of Santa Cruz, the Monterey Bay, Watsonville, and Los Gatos. There were at least 63 deaths (some say 66) and 3,757 injuries as a result of this earthquake. The quake also caused an estimated $6 billion in property damage, the costliest natural disaster in U.S. history at the time. It was the largest earthquake to occur on the San Andreas Fault since the great 1906 San Francisco earthquake.

 

San Fernando Earthquake

TIME: February 9, 1971 / 6:01 am PSTLOCATION: 34° 24.67' N, 118° 24.04' W MAGNITUDE: 6.6

Also known as the Sylmar Earthquake, this earthquake occurred on the San Fernando fault zone, a zone of thrust faulting which broke the surface in the Sylmar-San Fernando Area. The total surface rupture was roughly 19 km (12 miles) long. (Prentice, 3) The maximum slip was up to 2 meters (6 feet). ??The earthquake caused over $500 million in property damage and 65 deaths. Most of the deaths occurred when the Veteran's Administration Hospital collapsed. Several other hospitals, including the Olive View Community Hospital in Sylmar (pictured below) suffered severe damage. Newly constructed freeway overpasses also collapsed, in damage scenes similar to those which occurred 23 years later in the 1994 Northridge Earthquake. Loss of life could have been much greater had the earthquake struck at a busier time of ...