What If A Mega Earthquake Hit California

Catastrophic

earthquake

scenarios have been played out on the big screen for decades, terrifying viewers with

earthquake

s that can collapse skyscrapers or level entire cities. Here's

what

will happen if a big one hits the West Coast. On July 4, 2019, Ridgecrest, California, was hit by a magnitude 6.4 earthquake and then a magnitude 7.1 just a day later. But none of these compare to the long-awaited major disaster, which scientists predict will eventually hit the Gold Coast. But when it arrives,

what

will it really be like? Here's what experts say could happen in the seconds, hours and days after the big disaster. While experts can't know exactly when an earthquake will strike, they have a pretty good idea where.

California is located in a hot zone of faults, the most famous of which is the San Andreas Fault. John Vidale: You know, here in California there are dangers from several different types of earthquakes. The greatest danger comes from earthquakes on the San Andreas fault system. Narrator: On average, the San Andreas Fault ruptures every 150 years. The southern parts of the fault have been dormant for more than 200 years. Vidale: We really haven't had a major earthquake in Southern California since 1857. Narrator: In other words, we're overdue for a major shake. According to a 2008 federal report, the most likely scenario is a magnitude 7.8 earthquake that would rupture a 200-mile stretch along the southernmost part of the fault.

Vidale: It's basically moving soil several feet in a 50-square-mile area. So the power of a magnitude 7.8 earthquake is probably close to the power used statewide for a year. Basically, something we as a civilization have trouble creating, short of a nuclear explosion. Narrator: If you are near the epicenter of the earthquake, it will be almost impossible to remain standing. Vidale: People have the idea of ​​running out of bed, out of their buildings, and that is a terrible idea, because a lot of what we see in earthquakes are people with broken legs and people who have gone through glass.

The best thing to do, as we always say, is to duck, cover and hold on. Get under some furniture. The main point is to protect the head and chest. Narrator: During and immediately after the shaking, buildings could collapse. John Wallace: The number of buildings that were built before about 1980 is really significant, and most of these buildings are very vulnerable to damage and collapse. Narrator: In this time-lapse video, you can see how the building components would hold up in a high-magnitude earthquake. Wallace: Because the San Andreas will produce the kind of prolonged shaking that would be very damaging to very tall buildings in, say, downtown Los Angeles, Century City, Long Beach, etc.

In older steel buildings, the connections in them have not necessarily been designed to withstand the maximum forces that can actually be generated. Narrator: Unreinforced structures are the least stable, but even code-compliant buildings could collapse. John Stewart: The building code, with its minimum requirements, does not guarantee that the building will be operational after an earthquake. Your goal is not to kill anyone. There is a feeling that if it is modern, it is designed to code, it is earthquake-proof and everything should be fantastic, but that is not the reality. Narrator: Five steel skyscrapers could completely collapse, while another 10 will be red-tagged or unsafe to enter.

And no, the earthquake would not cause a tsunami, despite what the movies would have you believe. Vidale: To trigger a tsunami, you need an earthquake to move the ocean floor, and most of San Andrés is on land, so a little bit of waves would be generated from a San Andrés earthquake, but nothing that was dangerous. Narrator: The earthquake could kill up to 1,800 people and injure 50,000 or more. While people could die from falling debris and collapsed structures, the greatest number of deaths would occur from fires. Vidale: Historically, the greatest danger from earthquakes has been fire.

In the 1906 earthquake there were 3,000 or 4,000 people who were simply trapped in that wave of fire that devastated the city. Narrator: The consequences of the great disaster will wreak havoc on infrastructure and the economy. Scott Brandenberg: Beneath our streets and our buildings is a really complicated network of infrastructure that could be damaged, and a lot of the things we take for granted every day will no longer be available, right? Like water, electricity, being able to drive where necessary. Narrator: Parts of the San Andreas Fault are intersected by 39 oil and gas pipelines. This could rupture high-pressure gas lines, releasing gas into the air and causing potentially deadly explosions.

Stewart: So if you have natural gas pipelines that break, that's how fires and explosions can occur. Narrator: And after the fires are out, one of the biggest concerns in a major earthquake is access to fresh water. All major aqueduct networks pumping water to Southern California cross the San Andreas Fault and could be severely damaged. Stewart: Then we would be left without the livelihoods that bring imported water to the region. They cross tunnels, they cross aqueducts near the surface. All of these would break and therefore we would be losing 60% of our water supply. Many of these water distribution lines are near sewer lines, which would also be broken, so now we have a situation where contaminants are potentially entering the water supply.

Narrator: Experts say you should have at least a two-week supply of water in your home. As the ground shakes and sediment shifts, there will be mudslides throughout Ventura and western Los Angeles County. Brandenberg: Thousands of landslides could occur. There have been earthquakes that have produced thousands. Landslides can definitely cause deaths and property damage. We have a lot of people who live in the hills. Good? So that's the place where you're likely to see landslides affecting people. Narrator: And finally, the biggest one will seriously affect the economy. Major transportation networks, such as roads and railways, could be unusable for weeks and even months.

Brandenberg: Some bridges may not be passable after an earthquake. We have had bridges collapse during previous earthquakes. Stewart: We could start to see the departure of key industries, the loss of population, and this could have, you know, devastating long-term impacts for the region. Narrator: The estimated financial cost of the largest is a whopping $200 billion, with $33 billion in building damage and $50 billion in lost economic activity. This all sounds pretty bad, but keep in mind that it is based on a worst-case scenario. The true impact of a large earthquake is based on a variety of unknown factors. Additionally, smaller earthquakes on faults directly beneath major population centers are a serious concern.

Vidale: But the worst earthquakes are difficult to predict. You know, that earthquake in Japan in 2011, its cost was almost entirely due to its nuclear power plant melting down. It is very difficult to predict what will fail in a large earthquake. Narrator: So how can Californians prepare for the big disaster? Brandenberg: We actually have a plan in place. You know, where are you going to meet? What are you going to do? Have water ready. I have a 55 gallon drum full of water. I put a chemical additive in it to make it drinkable for five years. Fifty-five gallons is the right amount for me...

I have a family of four. That will last us two weeks. Canned food. You know, you have to be prepared. I'd say it's best to plan to stay where you are. Leaving Los Angeles is bad enough without an earthquake, right? The traffic is already terrible. If the roads are closed and people try to get out, it will be really bad.