Disaster in California I went to the San Andreas Fault | Discovey Geology

I'm here on the Pacific continent. And I'm here on the North American continent. And even though we are both in the same location, we are actually standing on two adjacent tectonic plates on one of the most infamous fault lines, the San Andreas Fault. We are standing here on what might be ground zero for one of the biggest threats that Southern California faces today. But enough talk. More data! It's data time! The San Andreas Fault is probably one of the most famous fault lines in the world. The fault line separates the North American plate from the Pacific plate. It runs down the length of California, goes right through San Francisco, and right by Los Angeles. Growing up in California, you've had to have known about the San Andreas. You could say it's our own fault for not knowing about it. This fault has a right lateral strike-slip motion. This means that the two plates are effectively moving horizontally past each other. The Pacific plate is sliding north while the North American plate is sliding south. This slippage is extremely slow. The plates only move about an inch and a half each year. However, that's just the average rate of motion. These slippages don't happen every year. The pressure builds up more and more over the years and then slips in one large earthquake. This is what is most concerning about fault lines like this one. Most of this fault line in Southern California is covered by development. By the way, if you live in San Bernardino, you're like right on top of the fault line. If we want to actually see artifacts of the fault line on the earth, we have to drive out of the city to the Californian countryside. You know what this means. It's road trip time! As you drive north from Los Angeles on Interstate 5, you'll eventually climb to Tahoon Pass. Tahoon Pass is the summit of a mountain range, which actually runs right along the fault line. Here on the side of the road, you can actually see where one plate is scraping past the other. On one side, we can see the Pacific plate, and on the other side, we have the North American plate. On the first side, we can see gray metamorphic quartz monzonite of the Pacific plate. And on the other side, we see the rich brown sedimentary sandstone and siltstone of the North American plate. These two different rocks could not have formed together on their own. They could have only been brought together by the movement of the sliding plates. Between these two plates is a layer of black rock known as fault gouge. This is where the actual fault line resides. The rock here has actually been pulverized and cooked by the friction that comes from the plates sliding past each other during earthquakes. If an earthquake were to hit here, it would have to cut across Interstate 5, potentially severing a major transportation route to and from Los Angeles. As we continue north on Interstate 5 and down into the Central California Valley, we turn west and find ourselves in the Carrizo Plain. This is a very rural area with no development built over the fault line, allowing us to see its effects on the local geography. Most of the fault line is actually quite difficult to see due to no fault of its own. Are you going to keep doing that? Probably the best place to actually see the fault is at Elkhorn Scarp, and the best way to see it is from above. Here we can see the very pronounced dip that is the border between the two continents. We can also see the effects of the shifting plates on the local waterways. Creeks that cross the fault line will actually have their courses rerouted due to the shifting plates. Here we can see the effects of the fault line on Wallace Creek. At one time, the creek flowed naturally through the valley, but due to the fact that the fault line cuts right across it, the creek now takes a sharp turn before turning back to its original course. You can actually see the creek from the air making right angles. This detour is about 400 feet in length. To the south of the fault line, we can find a shallow alkaline endorheic lake known as Soda Lake. The San Andreas Fault formed Soda Lake by changing the course of a stream, preventing it from draining out of the valley. So when will the next big earthquake hit us? Unfortunately, that question is more elusive than anyone wants. The last earthquake on the fault line was in 2004 in Parkfield, California. This was only a 6.0 magnitude earthquake, and Parkfield actually gets consistent earthquakes every few decades. Due to their high frequency, the earthquakes here are typically not that severe. Before that was the infamous 1906 earthquake in San Francisco, which was a 7.8 in magnitude. That earthquake killed at least 3,000 people and destroyed 80% of the city. This is one of the worst earthquakes in American history and the deadliest natural disaster in all of California history. Before that was the 1857 Fort Tejon earthquake, which, despite its name, was located, once again, in Parkfield, California. This was a 7.9 magnitude earthquake. There were only two deaths reported, but this was 1857 and the population of California was less than half a million. But the last big one that Los Angeles faced was 300 years ago. This was so long ago that we don't have an exact recording of when it happened or how big it was. This means that the plates in Southern California have been building up tension for 300 years without any major release. The prediction is that when the fault slips, the earthquake will be huge. In 2015, the Uniform California Earthquake Rupture Forecast published its prediction of when the big one would hit. It predicted that in the next 30 years, Southern California had a 100% chance of seeing a 6.0 magnitude earthquake or greater. Furthermore, there is a 75% chance of a 7.0 earthquake and a 7% chance of an 8.0 earthquake. Ugh, that sounds terrible. How can we avoid it? Well, we can't really. Unlike hurricanes, tornadoes, or wildfires, there is really no warning when an earthquake will hit. California has been retrofitting buildings to withstand earthquakes, but not all buildings have been retrofitted. Also, even if buildings withstand the earthquake, there is still a concern that the roads will be smashed and that the power and water distribution will be cut off for an extended period of time. Remember the 1906 earthquake in San Francisco? Most of the damage didn't come from the actual earthquake, but from the fires that erupted after the gas mains ruptured. If the big one hits us, there will likely be a period of time when people are unable to leave the area and unable to get critical resources like food, water, and medical care. So, what can people do? Being prepared to survive without access to power, running water, or food is vital. Make sure you have plenty of water stored at home. You should store about one gallon per person per day. Also, keep a large amount of food that doesn't need to be refrigerated or cooked. I have a bucket of freeze-dried food that has a shelf life of 25 years. You should also have flashlights, a fire extinguisher or fire blankets, a medical kit, a radio, since cell phones and internet will probably be down, and even liquid waste deodorizing powder, which you put into your bucket toilet. Yeah, that's a real thing. Wow, that sounds pretty involved. Yeah, it can seem like a daunting task, but it's far better to be prepared before a natural disaster rather than after. Everyone should be responsible for getting ready to handle this type of emergency. So, if you're not prepared for the big one, then I guess it's your own fault.