A magnitude 4.5 earthquake struck the San Francisco area early this Thursday morning 3 km Southeast of Berkeley.
The quake took place at 02:39:37.6 local time in California which is 5:39 AM on the east coast.
The quake was triggered by the “Hayward Fault” at a very shallow depth of only 13 km and was widely felt.
The Hayward Fault is a mostly right-lateral, strike-slip fault with approximately 5 mm/yr (1/5 inch/year) of creep. The 2003 Working Group for California Earthquake Probability, in agreement with previous working groups going back to 1990, assigned a slip rate on the Hayward Fault to be about 9 mm/yr (1/3 inch/year). This implies that approximately 4 mm/yr of motion is taken up in a stick-slip fashion, leading to the generation of earthquakes.
The Hayward Fault runs from San Pablo Bay in the north to Fremont in the south, passing through the cities of Berkeley, Oakland, Hayward, and Fremont. South of Fremont the fault branches into a complex set of surface faults that connect the Hayward Fault to the central part of the Calaveras Fault. The Hayward and Calaveras Faults may have a simpler connection at depths more than 5 km (3 miles), joining in the subsurface just south of the Calaveras Reservoir (site of the October 30, 2007 M5.4 Alum Rock earthquake). The Hayward Fault may be segmented into a northern and southern segment in the vicinity of Berkeley or Oakland.
The most recent major earthquake on the Hayward Fault occurred at 7:53 AM on 21 October 1868 with an estimated magnitude of ??. With an epicenter in the heart of the Bay Area, then having the largest population on the west coast with a total of 260,000 residents, this earthquake was one of the most destructive in California history, and remains the nation’s 12th most lethal earthquake. Property loss was extensive and 30 people were killed. Five deaths were reported in San Francisco, out of a population of 150,000, where the total property loss was estimated to be $350,000 (in 1868 dollars). This earthquake was known as the “great San Francisco earthquake” until the magnitude 7.9 shock on the San Andreas Fault on 18 April 1906.
Geologic studies at Tule Pond (Fremont) on the southern segment of the Hayward Fault have shown that the average interval between the past 5 earthquakes has been 140 ± 50 years. The average interval of the past 11 earthquakes on this segment of the fault is 170 ± 80 years.
The 2003 Working Group for California Earthquake Probability assigned a 27% probability that the Hayward-Rodgers Creek Fault system would produce a magnitude 6.7 or larger earthquake in the next 30 years.
The BIG ONE Is Inevitable. But When?
The ‘Big One’ is a hypothetical earthquake of magnitude ~8 or greater that is expected to happen along the SAF. Such a quake will produce devastation to human civilization within about 50-100 miles of the SAF quake zone, especially in urban areas like Palm Springs, Los Angeles and San Francisco.
No one knows when the Big One (“BO”) will happen because scientists cannot yet predict earthquakes with any precision. The 1906 San Francisco quake (mag ~7.8) and the 1857 Ft. Tejon quake (mag ~7.9) took place in northern and central California, respectively, and both were ‘Big Ones’. Some scientists think the next BO will be in southern California. The SAF passes through LA’s three main transportation, power, and utility corridors in southern California: I-10 in San Gorgonio (Banning) Pass, I-15 in Cajon Pass and I-5 in Tejon Pass.
The San Francisco peninsula’s water supply is contained in San Andreas Lake (!) and the Crystal Springs reservoirs, both squarely on the SAF. Earthquakes with magnitude 8.5 or greater can probably only happen in California north of Cape Mendocino where the Cascadia megathrust subduction zone lies, but they are extremely rare, occurring on average once every few hundred years.
Smaller but still devastating earthquakes can happen on other faults as well: San Jacinto fault in southern California and the Hayward fault in the San Francisco Bay area. Recent experience with the Northridge quake shows that smaller and sometimes unknown faults can be a problem; until the earthquake, we did not know about the Northridge fault because it is a blind thrust fault.
Even those who survive the immediate earthquake will find themselves in danger. The first thing they will need is water, but most water mains will probably have been broken. Utilities such as electricity, natural gas, gasoline, telephones, etc. will be interrupted for days, weeks or longer. Medical facilities will be jammed and unable to handle the casualties. Most people will not be able to get to the hospital because roads will be damaged.
Banks will be closed, as will any organization that relies on the internet. Little if any food or medicine will reach the area, and radio/TV communications will be spotty at best.
The best way to prepare for the BO is to plan on camping for two weeks; think sleeping bags, tents, and living outdoors. This means not only basic necessities (food, water, clothing, shelter) but the knowledge of how to survive. For more information visit the News-Prepper!
So why be concerned about one now?
The real question that you have to ask yourself is: would you be prepared?
The second most important question is: are you prepared right now to survive such a catastrophe?
Let’s take a look at this video and find out!
Are You Ready America ?
End of The World Begin From Japan?
And Next Australia,Canada,UK…