A Shaky Myth

ANAHEIM - Over the last few weeks there have been some minor earthquakes in the Los Angeles area. These minor shakers have wiggled the ground just enough to get a lot of people's attention, and making a lot of people wonder what all this shaking may be about. On Sunday, April 12, there was a magnitude (M) 3.3 shaker in the West L.A. area that appears to be on the Newport-Inglewood Fault, on Wednesday, April 15, there was a M3.1 in the Sylmar area, and on Saturday, April 2, there were several minor earthquakes in the Newhall Pass area with the largest quake being M3.2.


Kinemetrics seismograph used by United States Department of the Interior. Photograph used under Creative Commons license.

If you grew up in Southern California, or even Japan, or really anywhere in the world that is considered "earthquake country," you probably have heard immense myths about earthquakes.

Is There Anything To These Earthquake Myths?

The short answer: NO! We all want an answer to the unknowable, especially if it is something that can greatly impact our lives and, frankly, our way of life, within just a few seconds, but at this time there is no scientific data and proof to accurately and precisely predict when a big earthquake will occur. With decades filled with tons of scientific studies, myths about earthquakes have been proven to be just that, myths.

Dolphins and Whales On The Beach

In recent weeks there has been a story floating around that several beached dolphins off the coast of Japan means a big earthquake is going to happen, because this happened once before off the Japan coast days before the great 2011 Japan earthquake. Furthermore, this, the sudden beaching of dolphins and whales, has also happened before large earthquakes in New Zealand and Chile.

Well, the beaching of dolphins and whales has happened in many other places many times before, and there has been no large earthquake in the following days. Thus, there has been no conclusive evidence that beaching of these great sea animals mean a big earthquake is imminent.

Full Moon Pulling The Gravity

Another very common myth is large earthquakes occur when there is a full Moon due to the Moon's gravity pull on earth. Well, out of all these earthquake myths this one has some truth to it as scientists at the United States Geological Survey have, "found a correlation between earth tides (caused by the position of the moon relative to the earth) and some types of earthquakes."

However, please understand that earthquakes can and do happen whether or not the Moon is shining bright in the sky, and thus the Moon is NOT a viable way to predict earthquakes.

Big Shakes Only In The Morning

If you grew up in Southern California you probably remember all too well that our most "memorable" earthquakes occurred early in the morning, which has lead a lot of people to believe only big earthquakes will only happen in the morning. This is a very big myth. The fact that major earthquakes have occurred in Southern California in the morning hours is simply a roll of the dice when Mother Nature has decided to give us a big shake. That is a way of saying it simply is by pure chance that large earthquakes have happened in the morning and there is no scientific proof that significant earthquakes occur in Southern California only in the morning hours. In fact, the 1933 Long Beach Earthquake happened at 5:55 p.m. Bottom line, "The Big One," or the next big enough one, can happen at 4:31 in the morning, or 4:31 in the afternoon.

Earthquake Weather

Probably one of the biggest myths in Southern California is so-called "earthquake weather." The common belief in Southern California is when it suddenly warms up earthquakes will happen. Well, many studies have shown when the earth decides to shake it gives no thought to the weather. After all, there have been major earthquakes in Southern California on Christmas Day and in the middle of summer.

Animals Know When An Earthquake Is About To Happen

Many people have said that right before an earthquake their pet, typically a dog or cat, "acted weird" or suddenly began running about without any reason. In most cases what animals are sensing are the P-Waves of an earthquake, which can be detected by sensitive animals, and sometimes sensitive humans. There have been cases where people report animals acting "weird" a few days before an earthquake. Plenty of studies have been done on this subject, and studies in China in the 1970s thought there might have been a breakthrough with animals helping predict earthquakes. Well, like many studies of possible earthquake precursors and predictions, observing animals has proven to be inconclusive, and thus animals cannot predict earthquakes.

What About Earthquakes Being Predicted To Happen In 20 Years

When geologists and seismologists talk about an earthquake happening either in a certain region or on a certain earthquake fault-line what they are doing is forecasting, not predicting. The words forecast and prediction are sometimes used interchangeably, but they have very different meanings when it comes to seismology. When it comes to earthquakes seismologists, for example, look at the history of a fault-line and how often it has produced a major earthquake, otherwise called paleoseismology. If, for example, a fault-line has produced a major earthquake on average every 100 years and it has been 70 years since the said fault-line last rupture seismologists will forecast the fault-line will produce a major earthquake within the next 30 years. Ostensibly, using our example, if it has been, say, 120 years since the last major earthquake on said fault-line you will hear that we are overdue for a major earthquake.

Caution In Earthquake Forecasting

While paleoseismology has been one of the best breakthroughs in figuring out how often a certain fault-line ruptures it must be stressed that while the average rupture may be, for example, every 100 years, it has also showed what could be best described as anomalies. That is to say even though the fault-line is suppose to cause a major earthquake on average around every 100 years sometimes, as paleoseismology shows, the said fault-line may of had a period in the past where it did not have a major earthquake for 200 or even 300 years.

On the other end, paleoseismology has showed major earthquakes on the studied fault-line, using our example, have occurred less than 100 years apart.

Think of it this way, you know how on the seven-day weather forecast on the seventh day they say a major storm is coming based on all the information on the way the storm pattern is shaping up, and come that seventh day the storm is nowhere to be found and it is very sunny outside. Well, long-term earthquake forecasting is kind of like long-term weather forecasting. Everything is lined up and based on all evidence it looks like an event should happened and thus is forecast to happen, like a big rain storm or big earthquake, but it just fails to happen.

Will There Ever Be Day Where We Can Predict Earthquakes?

Well, never say "never," but in general when it comes to earthquake prediction the geologist and seismologist community has kind of moved on to long-range earthquake forecasting, such as more paleoseismology studies, and developing and funding earthquake early warning systems.

It is very important to understand that the study of earthquakes is an extraordinarily young science and even when major earthquakes have occurred scientists have learned something new. After all, it was the 1994 Northridge Earthquake that showed how dangerous blind thrust faults are to the L.A. area and gave way to more studies of such faults like, The Puente Hills Thrust Fault.

Even though the earth science community in general is moving away from precise earthquake prediction please have no fear, because many professional, retired, government, amateur and wanna-be geologists and seismologists are still looking for that Holy Grail of trying to solve that puzzle of accurately predicting earthquakes.

So, The Bottom Line Is The One Thing Nobody Wants To Hear...

Even with all the marvelous advances in technology there is still no accurate way to predict when precisely a major earthquake will occur. It could happen one minute from now, or another 20 years, or even another 100 years from today. All you can do is prepare.

Five Odd Southern California Earthquake Facts

HOLLYWOOD - Looking up Vine Street from Hollywood Boulevard the sudden rise of the street just above Yucca St. on the hill where The Hollywood Freeway lays atop shows the not so subtle signs of The Hollywood Fault, which has been in the news lately. Recent mapping by the California Geological Survey shows the fault is what helps give Hollywood and Los Feliz its character with its hills, and while the beauty is nice some developers are none too happy with this study.

When The Hollywood Fault, or any Southern California fault, will rupture with fury again is not clear as there are no accurate ways to predict earthquakes (not to be confused with forecasting earthquakes).

Walking over and along The Hollywood Fault on Los Feliz Blvd. one wonders about earthquakes past, and thus this piece is not about unhappy developers not getting their way, or even so much The Hollywood Fault, but rather five odd, peculiar Southern California earthquake facts.


Severe freeway damage following the 1971 Sylmar Earthquake. Used under a Creative Commons license.

1 - The First Earthquake on Record

For thousands and thousands of years earthquakes, both very small and very large, have been happening in Southern California, as paleoseismology has proven, but while there were many animals and trees to feel the shaking as hills and mountains were being pushed up there were hardly many humans around. Any humans that were around never kept anything written about it, or hid their diary.

It would not be until 1769 that the first earthquake in Southern California would be recorded. Gaspar de Portola, Father Juan Crespí and a group of over 60 explorers from Spain, in the name to extend Spain's control up the Pacific Coast and establish colonies and missions (and hopefully prevent Russia and England from acquiring and taking this territory), set out from San Diego to Monterey on July 14, 1769. Maps at the time available to de Portola's group showed California extending from San Diego only to the Monterey Bay.


When California was still thought of as an island in this 1745 map of California, and so not unusual to think de Portola's group thought the soon-to-be Golden State went as far as Monterey. Used under Creative Commons license.

After about a couple weeks of walking from San Diego to current day Orange County on July 28, 1769 and setting up camp at what is now The Santa Ana River in Anaheim de Portola's group felt a very large earthquake.

This earthquake occurred around 4 p.m., and the explorers recorded many aftershocks, several of them strong, as they made their way into the San Gabriel Valley. Records kept by de Portola's group show they stopped feeling any earthquakes when they were exiting the San Fernando Valley.

Among geologists, seismologists and historians there is much debate on just how big this earthquake was and just where the epicenter was located. Given the records by the de Portola team it was believed by many in the science and historic communities this earthquake was around magnitude 6.0 and probably on The San Jacinto Fault in the Inland Empire. Part of this was based on the diaries of the de Portola team saying they felt no more earthquakes once exiting the San Fernando Valley.

The United States Geological Survey (USGS) officially lists this earthquake, the very first earthquake in a long, forever growing list of Southern California earthquakes cataloged by the USGS, as M6.0 in the Los Angeles Basin. 

The when and where of this first recorded Southern California earthquake by the USGS has been challenged by University of California-Irvine geology professor Lisa Grant. Ms. Grant has proposed that the 1769 earthquake was actually M7.3 located on the relatively unknown San Joaquin Hills Fault located between Newport Beach and Laguna Beach, which resulted in the Orange County coastline being raised by almost 11 feet.


Put together by The Southern California Earthquake Center here is a scenario of a M6.7 earthquake on The San Joaquin Hills Fault.

The video above, combined with the diaries kept by the de Portola team, shows the theory by the UCI professor to be possible as strong shaking wanes in The San Fernando Valley. One thing the debate of the 1769 earthquake has brought up is the fact that Orange County has a major earthquake fault line that is not really well known, which has brought on more studies of the fault.

The when and where of this very first recorded Southern California earthquake still fascinates geologists and seismologists. Among other reasons, figuring out the mystery of this earthquake may help further understand and clarify the nature of earthquakes in Southern California (like the existence of a major earthquake fault in Orange County).

2 - Last Large Earthquake on Record

The last large earthquake in Southern California was a M7.9 in 1857, which is commonly called The Fort Tejon Earthquake. Not only was this the largest earthquake in Southern California recorded history, but this was one the largest earthquakes ever recorded in the United States.

This was also the last time The San Andreas Fault had a major rupture in Southern California. The infamous fault line is believed to have ruptured near Parkfield and continued rupturing south to just near The Cajon Pass. In fact, this was the last time "The Big One" happened in Southern California.

Southern California was nowhere near the megalopolis it is today, and so damage was limited to scars in the Earth. There were many scares in the Earth with cracks reported in the San Gabriel Valley and in the San Bernardino area.

In some areas the shaking is believed to have lasted up to, and even over three minutes. In Downtown L.A. the shaking is believed to have lasted over a minute.

Both the USGS and disaster planners fear the impact a repeat of this earthquake would have today.

The last time the lower southern segment of the San Andreas Fault between San Bernardino to the Salton Sea ruptured is believed to have been in or around 1690.

3 - Deadliest Earthquake Ever

The earthquake was only M6.4, but the deadliest earthquake in Southern California was the March 1933 Long Beach Earthquake, which killed 120 people. Much of the death was due to the brick construction of many buildings in Long Beach and Compton.


Compton in the aftermath of the 1933 earthquake. The fallen bricks are what killed many people in this earthquake. Used under a Creative Commons license.

Many schools were badly damaged, but luckily school was out when the earthquake struck at 5:55 p.m. (which should break the myth that big earthquakes only happen in the morning). Had this earthquake occurred just a few hours earlier the death toll would have been much higher with many school children killed.

This thought disturbed and worried a lot of people, and very quickly in April 1933 the state passed The Field Act that mandated earthquake resistant construction for schools.


Jefferson Junior High School in Long Beach after the quake. Damage to schools like this throughout the area and what could have been worried parents, teachers and students alike, which led to the passage of The Field Act. Used under a Creative Commons license.

In the 1971 Sylmar Earthquake schools built after The Field Act made it through with no damage while schools built before 1933 suffered major damage.


A newsreel showing the aftermath of the 1933 earthquake.

4 - The 1933 Epicenter Was NOT in Long Beach

The deadly jolt in 1933 will forever be known as The Long Beach Earthquake, but the epicenter was not in Long Beach. Rather, the epicenter was in Newport Beach on The Newport-Inglewood Fault.

While the damage was bad in Long Beach the earthquake ended up being the most damaging and deadliest earthquake in Orange County history. Most of the death and destruction was in Santa Ana. However there was also major damage in Garden Grove and Anaheim.


Very badly damaged building in Santa Ana. Used under Creative Commons license.

Damage was so bad in downtown Santa Ana that the Santa Ana Register, which was located in downtown Santa Ana, put together their newspaper working outside of their damaged building. 

Of course this would not be the first time an epicenter would be misidentified. The Sylmar Earthquake was not in Sylmar, but the hills above Sylmar. The Northridge Earthquake was not in Northridge, but in Reseda.

5 - The Christmas Day Earthquake

If you were asleep on Christmas morning in 1899 and felt the house shake you may have thought it was Santa Claus stuck in your chimney trying to wiggle his way out. It was not Santa, but Mother Nature showing that even big earthquakes do not get the holiday off.

At 4:25 a.m. a M6.5 earthquake stuck near San Jacinto on the fault of the same name, The San Jacinto Fault.

This earthquake was felt in a very wide area waking people up in Los Angeles, San Diego and as far as Santa Barbara.

Damage was greatest in San Jacinto and Hemet with many collapsed buildings. In Riverside many chimneys were knocked down and cracks in many buildings appeared. In fact, throughout much of the then sparsely populated Inland Empire the damage reports were much the same along with shattered windows.

The earthquake was deadly at the nearby Soboba Indian Reservation, where six people were killed by falling adobe walls.

In the Earth sciences community there is a little bit of debate if whether this earthquake was larger than M6.5 and just where exactly the epicenter was located. The Southern California Earthquake Center believes the epicenter may have been ten miles south of San Jacinto.

In the end, whether an earthquake hits on Christmas morning or during an imperialistic exploration journey, it is extraordinarily important to be prepared for the next big earthquake.

On This Date: The 1933 Long Beach Earthquake

LONG BEACH - On Sunday night a magnitude 6.8 earthquake struck about 50 miles west of Eureka in the Pacific Ocean, according to the United States Geological Survey, and it was felt throughout much of the Northern California and southern Oregon. With this earthquake being some distance from land there was not much damage.

Sunday night's earthquake struck at 10:18 p.m., and was under a couple hours shy of occurring on March 10, which is the anniversary of a much less powerful earthquake that also had an epicenter in the Pacific Ocean, but caused much severe damage.

On March 10, 1933, at 5:54 p.m. with a magnitude 6.4 the deadliest earthquake in Southern California history on record hit resulting in 120 reported deaths and caused, in 2014 dollars, $899,676,923 worth of damage.

Commonly referred to as the Long Beach Earthquake, as damage was great in Long Beach and Compton with many collapsed buildings, the epicenter of this earthquake was actually about a mile west of Newport Beach in the Pacific Ocean.


Aftermath of the 1933 earthquake along Main Street in Compton.  No copyright infringement intended; shown for historic and educational purposes only.   

As Carey McWilliams would point out, many boosters and chamber of commerce types often sold Southern California, aside from being the land of sunshine and oranges, as a place where big earthquakes do not ever happen, despite the fact that within the last 34 years leading up to 1933 there were at least three notable earthquakes in Southern California. Of course much of the same was said and done in San Francisco before and after the 1906 earthquake with their boosters claiming it was just a great fire that destroyed most of San Francisco in 1906 and ignoring large quakes in the Bay Area prior to 1906.

Nonetheless this earthquake was really the first event that brought to light many hazards and potential hazards earthquakes pose to modern Southern California.

With so many collapsed buildings the most important thing to come from the 1933 earthquake was a piece of legislation called, The Field Act. The Field Act was the first major piece of legislation that mandated earthquake resistant construction, which was specifically aimed for schools. When this earthquake struck many schools collapsed due mainly to unreinforced masonry construction, and, as has been pointed out many times over and still worth repeating, had this earthquake struck just a few hours earlier many, perhaps hundreds, of school children likely would have perished. Records show at least 250 schools were destroyed in this earthquake.


Severe damage at Thomas Jefferson Junior High School in Long Beach as a result of the 1933 earthquake. No copyright infringement intended; shown for historic and educational purposes only.

The 1933 earthquake then and now vividly shows the dangers the Newport-Inglewood Fault poses to the Los Angeles basin. Many geologists and seismologists believe this fault can produce a magnitude 7.4 earthquake, and that such a major event on this fault could be much worse in terms of damage and casualties in L.A. and Orange County than perhaps an event on the San Andreas Fault.

With its epicenter just off the coast in Newport Beach this quake still holds the record as being the most deadly and damaging earthquake in Orange County history with major damage in Santa Ana, Garden Grove and Anaheim.

Damage to a Santa Ana building as a result of the 1933 earthquake. No copyright infringement intended; shown for historic and educational purposes only.   

Historic film footage of the aftermath of the Long Beach Earthquake. No copyright infringement intended; shown for historic and educational purposes only.

A very important lesson we should all take from this earthquake is that it should dispel the myth that big earthquakes in Southern California only occur in the middle of the night or early morning. For anybody who grew up or lived in the Southern California for the past 25-plus years probably know that our major earthquakes have occurred during the early morning hours, and this has lead some people to believe big quakes only hit around that time. As USGS and other scientists have stressed many times over, it is simply luck that Southern California's recent large earthquakes have hit in the early morning. Seismologists and emergency planners stress that a major earthquake could hit at anytime, as this one did in 1933 at 5:54 p.m.

As old photographs show the Southern California coast, particularly in the Huntington Beach area, used to be dotted with oil wells. It was reported about two hours before the earthquake the pressure in Huntington Beach oil wells dropped. Geologists and seismologists have studied pressure drops in oil wells before and after earthquakes, but however at this time the whole correlation and causation of pressure drops and earthquakes has not added up, so to speak.

It would not be until the 1971 Sylmar Earthquake that the L.A. basin would experience its next damaging and deadly earthquake, and not until the 1952 Kern County Earthquakes that California would have its next damaging and deadly earthquake.

The Newport-Inglewood Fault is still highly active, and was likely responsible for the May 17, 2009 M4.7 earthquake near Inglewood. This fault may possibly be responsible for the series of minor earthquakes in and around the Marina Del Rey area within the last year and a half.

In very modern times the Newport-Inglewood Fault made it presence known in Orange County when on April 7, 1989 a M4.7 occurred right under Newport Beach. That quake caused items to fall off shelves at the Newport Beach Fashion Center and other such property damage around Orange County. It was the last notable sized earthquake in Orange County.

There is that whole thing about history and learning from the past, and not repeating it. Sometimes earthquakes have a tendency to strike the same area twice or more and that cannot be helped, but to avoid mistakes of the past we can all be prepared.

The 1933 earthquake shows big quakes can hit in the middle of rush hour, and an earthquake of this size with its Newport Beach epicenter can and likely will cause damage in the L.A. and O.C. metro area. Any time an earthquake at or above magnitude 6 hits in an urban area that is when you can expect damage, even in an area that is suppose to be "built" to resist quake damage.

As we always do when we talk about earthquakes on this site we stress the importance of being prepared, and remember, that at this time there is no way to predict earthquakes.

A Quick Take: Three Fun Facts About OC

ANAHEIM - Here are three quick interesting facts about Orange County you may or may not have known.

1. The name Anaheim is a fusion of two names: Heim, which is the German and Norwegian for home, and Ana, which was short for Santa Ana River. Perhaps at the first town meeting with the German settlers and winemakers from San Francisco it may have gone like this: "There's a river over there the locals call Santa Ana. Heim. Ana. Ana. Heim. Anaheim!"

2. Ever maybe notice Balboa Boulevard in the Balboa Peninsula in Newport Beach kind of looks like it almost should have some kind a light rail running in the middle of the street? Well, once upon a time it actually did, the Pacific Electric ran a trolley down the middle of that street to the bay. That line was originally constructed by Los Angeles Inter-Urban Electric Railway, but PE took it over in July 1908. The railway was a big boom to the then quiet peninsula.

3. In 1933 the deadest earthquake in Southern California on record occurred, and it is commonly referred to as The Long Beach Earthquake, which resulted in 120 reported deaths. There was indeed great damage in Long Beach and Compton, but the epicenter was actually just off the coast in Newport Beach along the Newport-Inglewood Fault. This earthquake was also the most damaging earthquake in Orange County history with major damage in Santa Ana, Garden Grove and Anaheim.

Damage to a Santa Ana building as a result of the 1933 earthquake. No copyright infringement intended; shown for historic and educational purposes only.