Earthquake Los Angeles Shakes California Residents

By: Susan Harris
Staff Writer
Published: Mar 16, 2010

U.S. Geological Survey records magnitude 4.4 earthquake 10 miles east of Los Angeles.

The early morning Los Angeles earthquake woke up California at 4:00 a.m., 7:00 a.m. eastern, and was centered about 10 miles east of downtown. The depth was recorded at about 11 miles making it a shallow earthquake. The U.S. Geological Survey (USGS) said the quake was felt from San Diego to Santa Clarita.

County fire and rescue officials are still surveying the area. There are no immediate reports of damage or injuries. However, the earthquake was considerably weak, but it did wake up residents east of the city.

The quake was centered near the October 1987 Whittier Narrows earthquake. That was a magnitude 5.9 quake that killed eight people and caused more than $350 million in damage. Officials have not identified the fault involved in this morning's quake.

Pacific Ring Of Fire

Los Angeles is subject to earthquakes due to its location in the Pacific Ring of Fire. The geologic instability produces numerous fault lines both above and below ground. It produces approximately 10,000 earthquakes every year.

One of the major fault lines is the San Andreas Fault. The fault line is located at the boundary between the Pacific Plate and the North American Plate. It is predicted to be the source of Southern California's next big earthquake.

Major earthquakes to hit the area include the 1994 Northridge earthquake, the 1987 Whittier Narrows earthquake, the 1971 San Fernando earthquake near Sylmar, and the 1933 Long Beach earthquake. However, all but a few quakes are of low intensity and are not felt. Parts of the city are also vulnerable to Pacific Ocean tsunamis caused by the quakes.

San Andreas Fault

The San Andreas fault is not a single fault, but rather an actual fault zone made up of many segments. Movement may occur along any of the fault segments along the zone at any time. The San Andreas fault system is more than 800 miles long, and in some spots is as much as 10 miles deep.

Largest Quake Ever Recorded

The largest earthquake ever recorded in the United States was a magnitude 9.2 that struck Prince William Sound, Alaska on March 28, 1964. The largest recorded earthquake in the world was a magnitude 9.5 in Chile on May 22, 1960. The earliest reported earthquake in California was felt in 1769 by the exploring expedition of Gaspar de Portola while the group was camping about 30 miles southeast of Los Angeles.

The world's deadliest recorded earthquake occurred in 1556 in central China. It struck a region where most people lived in caves carved from soft rock. These dwellings collapsed during the earthquake, killing about 830,000 people. In 1976 another deadly earthquake struck in Tangshan, China, where more than 250,000 people were killed.

Magnitude

The magnitude of an earthquake is a measured value of the earthquake size. The magnitude is the same no matter where you are, or how strong or weak the shaking was in various locations. The intensity of an earthquake is a measure of the shaking created by the earthquake, and this value does vary with location.