4.5 Magnitude Quake Hits Southern California

LOS ANGELES, CA — A magnitude 4.5 quake struck Tuesday afternoon in Ridgecrest. It's the largest aftershock from the July 6 magnitude 7.1 quake in days, and it comes as seismologists monitor the quake activity with an eye toward nearby faults that could be triggered. The fault responsible for the Searles Valley series is growing longer with each big quake. Two nearby faults reportedly have the capability of casing major quakes in Southern California.

The quake struck at 1:15 p.m. Tuesday, and it was a shallow one — just 2.2 miles deep.

According to the U.S. Geological Survey, the Ridgecrest aftershocks are creeping closer and closer to the Owens Valley and Garlock Faults. The Owens Valley Fault, in the Mammoth area, is responsible for one of the largest California quakes on record and the Garlock skirts the Mojave Desert and could produce a major quake felt from Ventura County To San Diego County.

“Those are places we would be more concerned,” U.S. Geological Survey research geophysicist Morgan Page told the Los Angeles Times. “Little earthquakes are telling us where big earthquakes are more likely.”

The strikeslip responsible for the near-constant quakes hitting Ridgecrest over the past two weeks is not connected to the San Andreas fault which runs along the most populous parts of California, according to Seismologist Lucy Jones. The Ridgecrest quakes are not likely to trigger quakes along the San Andreas, which is more than 100 miles away, according to seismologists.

But the fault line is spreading, and that has the experts watching closely to see if it could trigger quakes along the major fault lines.

All of these large quakes are actually extending the fault line creating them, she explained.

"So the fault is growing," Jones said. "We ruptured a piece in the first earthquake."

And since then all of these large quakes are actually extending the fault line creating them, she explained.

THIS IS A DEVELOPING STORY. PLEASE REFRESH THE SCREEN FOR UPDATES

It was the latest in a series of quakes that seismologists are saying is a “wake up call” for Southern California which had been in a 20-year major earthquake drought leading up to the Fourth of July when a 6.4 magnitude quake rattled the Searles Valley followed by a major 7.1 temblor on July 5. Both quakes were the largest to hit Southern California in decades. Though epicentered in Ridgecrest near Death Valley, the quakes could be felt from the coast to Las Vegas and from the Bay Area to Mexico.

The largest quake was almost immediately followed by 15 aftershocks of notable size including six quakes larger than a magnitude 4.0. Within two hours, dozens of aftershocks hit, with most ranging from magnitude 3.0 to 5.5. Within five days, more than 1,350 quakes of magnitude 2.5 or larger struck the region, and 29 of them have been magnitude 4.5 or larger.

Seismologist Dr. Lucy Jones warned residents to expect more aftershocks

"According to our forecast, over the next 1 Week there is a 4% chance of one or more aftershocks that are larger than magnitude 7.1,” the US Geological Survey announced following the July 5 temblor. “It is likely that there will be smaller earthquakes over the next 1 Week, with 360 to 660 magnitude 3 or higher aftershocks."

The July 5 quake was blamed for one fatality in Pahrump, Nevada. It briefly caused the town of Trona to lose water and triggered power outages as far away as Los Angeles. A handful of fires were reported around Ridgecrest, and some homes sustained major damages such as foundation cracks, collapsing chimneys and shattered windows.