Even at the onset of hurricane Harvey and now hurricane Irma, we could not help but to think we were and are seeing future visions of what could happen here in the Los Angeles region after a major magnitude earthquake. For the last twenty years we have heard experts warn of mass destruction and even chaos that would follow in the wake of a major Southern California earthquake. Just like the hurricanes we are now seeing, a major earthquake would be just as catastrophic.
We have been warning many along with others that preparedness is the key to survival and recovery after a major earthquake. Some are saying that the preparedness message is getting a huge boost as a result of the recent hurricanes in Texas and now Florida. Our fear is that like past disasters, the preparedness boost will fade away in time. Preparedness seems to be like a fad and like all fads they fizzle out. People will eventually put preparedness on the backburner until the next disaster strikes somewhere in the United States. We have seen this scenarion play out over and over again.
The warnings from 20 years ago are just as relevant today as they were then but today the warnings are more dire especially with all the new data painting a very bleak picture of life after a major earthquake in the Southern California region. Just like Texas and now Florida, a major quake will alter daily life for many for months, maybe years after the initial shock.
As we look at history in terms of earthquakes here in the Los Angeles region, we are reminded of the 1971 Sylmar quake (6.7), the 1992 Landers quake (7.3) and the 1994 Northridge quake (6.7). All these earthquakes caused damage, injuries and death. These quakes caused damage in small concentrated areas and disrupted life for many from days to weeks after the initial shock. Experts agree and are pretty sure that a major magnitude earthquake (8.0+) will strike the region and the toll will be much greater.
When it comes to the “Big One”, the danger lies on the San Andreas fault which runs from Bombay Beach to Mendocino Triple Junction. That is a whopping 750 miles of fault line that could rupture. The San Andreas fault has a long history of producing large earthquakes which has scientists and geologists very worried. In case you did not know but the San Andreas fault is the longest and fastest moving fault in California which will unleash the most powerful and destructive earthquake in our lifetimes. An 8.2 earthquake that originates on its most southern point would effect every city along its path at the same time. The damage would be unimaginable.
A study published in 2006 in the JournalNature found that the San Andreas fault has reached a sufficient stress level for an earthquake of magnitude greater than 7.0 on the moment magnitude scale to occur. This study also found that the risk of a large earthquake may be increasing more rapidly than scientists had previously believed. Moreover, the risk is currently concentrated on the southern section of the fault, i.e. the region around Los Angeles, because massive earthquakes have occurred relatively recently on the central (1857) and northern (1906) segments of the fault, while the southern section has not seen any similar rupture for at least 300 years. According to this study, a massive earthquake on that southern section of the San Andreas fault would result in major damage to the Palm Springs-Indio metropolitan area and other cities in San Bernardino, Riverside and Imperial counties in California, and Mexicali Municipality in Baja California. It would be strongly felt (and potentially cause significant damage) throughout much of Southern California, including densely populated areas of Los Angeles County, Ventura County, Orange County, San Diego County, Ensenada Municipality and Tijuana Municipality, Baja California, San Luis Rio Colorado in Sonora and Yuma, Arizona. Older buildings would be especially prone to damage or collapse, as would buildings built on unconsolidated gravel or in coastal areas where water tables are high (and thus subject to soil liquefaction).
Here is an excerpt from a recent article that speaks to the destruction of a Southern California earthquake:
Here are some of the findings of what could happen in a 7.8 earthquake that strikes at 10 a.m. on a dry, calm Thursday in November, based on feedback from 300 experts in both the private and public sectors:
The death toll could be one of the worst for a natural disaster in U.S. history: nearly 1,800, about the same number of deaths as resulted from Hurricane Katrina. More than 900 could die from fire; more than 400 from the collapse of vulnerable steel-frame buildings; more than 250 from other building damage; and more than 150 from transportation accidents, such as car crashes due to stoplights being out or broken bridges.
Los Angeles County could suffer the highest death toll, more than 1,000, followed by Orange County, with more than 350 dead; San Bernardino County, with more than 250 dead; and Riverside County, with more than 70 dead. Nearly 50,000 could be injured.
Main freeways to Las Vegas and Phoenix that cross the San Andreas fault would be destroyed in this scenario; Interstate 10 crosses the fault in a dozen spots and Interstate 15 would see the roadway sliced where it crosses the fault, with one part of the roadway shifted from the other by 15 feet, said Jones, who was the lead author of the ShakeOut report.
“Those freeways cross the fault, and when the fault moves, they will be destroyed, period,” Lucy Jones said. “To be that earthquake, it has to move that fault, and it has to break those roads.”
The aqueducts that bring in 88% of Los Angeles’ water supply and cross the San Andreas fault all could be damaged or destroyed, Lucy Jones said.
A big threat to life would be collapsed buildings. As many as 900 unretrofitted brick buildings close to the fault could come tumbling down on occupants, pedestrians on sidewalks and even roads, crushing cars and buses in the middle of the street.
Fifty brittle concrete buildings housing 7,500 people could completely or partially collapse. Five high-rise steel buildings — of a type known to be seismically vulnerable — holding 5,000 people could completely collapse.
Some 500,000 to 1 million people could be displaced from their homes, Lucy Jones said.
We are encouraging all Southern California residents to prepare for a major earthquake before it is too late. There are many resources available however if you need assistance for your homeowners group, your schools, your businesses, etc. we can be of assistance. Please call our offices at 747-444-1035 to schedule a guest speaker or for a consultation.