Earthquake swarm near Brawley, Southern California – A lot of damage + extensive update

Last update: August 27, 2012 at 9:20 pm by By Armand Vervaeck and James Daniell

Update 15:35 UTC :
– Some pictures are showing “liquefaction” which occurs often when strong shaking takes place in sandy soil. Liquefaction occurs in saturated soils, that is, soils in which the space between individual particles is completely filled with water. This water exerts a pressure on the soil particles that influences how tightly the particles themselves are pressed together. Prior to an earthquake, the water pressure is relatively low. However, earthquake shaking can cause the water pressure to increase to the point where the soil particles can readily move with respect to each other. Liquefaction can also be compared to quicksand. Most major earthquakes have cases of liquefaction
– For American standards, this earthquake was really damaging. No collapsed houses of course, but during the 2 years of our existence, this is only the third major damaging  incident (after Virginia and Oklahoma)
– Besides some structural damage to houses and mobile homes, a lot of damage has also occurred in the interiors of the houses. The many earthquakes (more than 300) have led to many minutes of shaking (sometimes strong the very strong) and make that everything may have been ok after the first set of earthquakes but tumbled because of the many aftershocks.
– 49 patients of the Pioneer’s Memorial Hospital have been transferred throughout the area
– In addition to the Brawley Fire department, 16 other Fire corpses have given a helping hand in Brawley.
– In 1940 a M6.9 earthquake struck the Brawley area, the most important so far and contradicting yesterdays remark of a seismologist than quakes are normally not higher than +5. To the positive side one can say that the area has released his stress and that more severe quakes are unlikely to happen (although nobody is sure about that)
– Seismologists as well as the local authorities are asking people to react the best possible way on eventual new strong shaking. The main advise (which can also be found at the right side on thios page) is : Do not try to run out of buildings while shaking is occurring because you never know what is falling off the roof. Heavy shaking also means that you can be knocked down while running away. Please wait until the shaking stops before running outside.
At earthquake-report.com we continuously see that 50 to 70% is not following this advise (even in Japan). As a sad reminder we can tell you that almost all of the Lorka Spain fatalities (7) were due to falling debris while running outside!

Update 09:25 UTC :
– Aftershocks are still striking the Brawley area but a lot less than yesterday afternoon. A M3.4 is the strongest one since more than 5 hours. Although many may not sleep too well, at least the shaking will not be responsible tonight. It is currently 02:25 AM in Brawley, California.
– The following schools will be closed on Monday due to the events : Del Rio Community School, Mulberry Elementary, Brawley Union High School, Barbara Worth Junior High School, Phil D. Swing Elementary School, Miguel Hidalgo Elementary School and J.W. Oakley Elementary School
– Up to 400 people are able to spend the night in a “emergency shelter” organized by the Red Cross
– A total of 21 mobile homes have been declared uninhabitable. A lot of houses have reported minor damage.  Many trailers have been pushed of their foundations
– NO serious injuries have been reported (source : Brawley city manager)
– Click here for the Local station KSWT NEWS 13 Video page

Update 06:04 UTC :
Our partner EQArchives has just finished an interactive map showing the epicenters of a big part of the swarm. Click on the image to go to the interactive map where you can zoom in and out.

Update 04:53 UTC :
– New M5.1 aftershock a few minutes ago. There has been some minor damage to old houses indicating around a intensity V-VI from the  earthquakes.
– Brawley Seismic Zone is well known for such sequences as stated before in 2005, 1981, 1970s, 1930s etc. so it should be expected that some more aftershocks / swarm earthquakes can occur in the coming hours and days.

Update 00:32 UTC :
– New M4.7 aftershock, one more of an impressive number of aftershocks
– Some trailers are simply being knocked off from their foundations
– The number of earthquakes recorded in the Imperial area must run into the hundreds (including the less than M2.5 earthquakes)

Click on the image for the normal size

Update 22:17 UTC :
– Minor damage is being reported in Brawley. No houses have collapsed and we do not expect to find such damage, however some structural damage has been reported in a number of buildings. Click on the Thumbnail to watch the image in the local Imperial Valley Press

Update 22:06 UTC
– Power has been restored in some Brawley areas but not yet everywhere.
– The earthquakes were also registered on the seismographs in Los Angeles. ABC7 network has a live Quake cam on the Internet. Click here to watch it Live

Update 21:46 UTC
– The last comparable seismic swarm in Brawley dates from 1970. Another one occurred in the 1930′s
– Some buildings in Brawley were evacuated after the first stronger quakes. People will probably stay outside for a while which is good in case other even stronger quakes would strike.
– The Brawley zone is a complex seismic area of smaller faults. The San Andreas main Fault runs from near Palm Springs to enter Mexico just west of Yuma.

The video below shows the strong shaking in Brawley, California. A family is enjoying sitting together in the living room when suddenly the shaking starts (after 25 seconds)

Update 21:38 UTC
– Damage assessments are currently being executed in the Brawley area.
– Imperial County has begun operating a “County Emergency Headquarters”
– Brawley has a population of 24,953 (latest census), not a small village. The town has a significant cattle and feed industry, and hosts the annual Cattle Call Rodeo. Year-round agriculture is an important economic activity in Brawley.
– Brawley has also a Geothermal power plan

for more information and updates, go to:    http://earthquake-report.com/2012/08/26/powerful-earthquake-swarm-in-southern-california-mexico-border/