Borrego Range, Southern California Earthquake

Strong earthquake in the Borrego range near Anza, Southern California

Last update: March 12, 2013 at 10:23 am by By

Update 18:10 UTC :  The earthquake was on the San Jacinto Fault, the most active in Southern California, said Lucy Jones, USGS science adviser for risk reduction. Aftershocks are expected.

Screen Shot 2013-03-11 at 19.19.27

Update 18:01 UTC :  Based on theoretical calculations 393,000 people will have experienced a light shaking (MMI IV) and 6.5 million people a weak to very weak shaking. Nothing special for Southern California, but the main difference in this case is that it was felt in such a huge area.

Update 17:46 UTC :  On the picture below you have a view of the desert mountain range where the earthquake struck. Except for some wildlife nobody will be around.

Anza Borrego Desert Wilderness State Park where the epicenter is -  image courtesy and copyright West Coast Sharon

Anza Borrego Desert Wilderness State Park where the epicenter is – image courtesy and copyright West Coast Sharon

Update 17:39 UTC :  Many Californians may have the same problems than we have : impossible to enter the USGS site.  The I Have Felt It Reports below will give you at least a good overview of how the people have experienced this earthquake.

Update 17:37 UTC : does not expect serious damage or injuries as the maximum theoretical shaking has been set to IV MMI (light shaking). This is mainly because the epicenter is in rocky mountainous area. Earthquake waves are not propagated very well in such ground.

Screen Shot 2013-03-11 at 18.57.28

Update 17:33 UTC :  The earthquake was felt from Los Angeles down to Northern Mexico (ie Mexicali). This is definitely one of the stronger earthquakes in California since the last couple of years.

Update 17:23 UTC : As you can see on our bottom map, the area had some very big earthquakes in the past.

Update 17:23 UTC : We have the impression that we are not the only ones having trouble with our servers as some USGS maps cannot be reached neither.

Update 17:20 UTC : USGS has updated his report and mentions now a M4.7 Magnitude at a depth of 12 km. 8 seconds later another one with the same Magnitude, but this may be changed again later on.

We have a hard time to write as we have too many readers in the site at the moment. Our apologies for this.
A lot of aftershocks are currently reported.
Luckily the epicenter is in a wilderness area but the valley to the east is of big concern.

Screen Shot 2013-03-11 at 18.08.14


19km (12mi) ESE of Anza, California
23km (14mi) SW of La Quinta, California
25km (16mi) SSW of Palm Desert, California
26km (16mi) SSW of Rancho Mirage, California
409km (254mi) W of Phoenix, Arizona

Most important Earthquake Data:

Magnitude : 4.7

Local Time (conversion only below land) : 2013-03-11 09:55:50

GMT/UTC Time : 2013-03-11 16:55:50

Depth (Hypocenter)  : 12.1 km