S1: Welcome in San Diego , it's Jade Hindman. Today we are talking about what could come next after Monday's quake and how to be prepared for the next one. This is KPBS Midday Edition. Connecting our communities through conversation. So yesterday , the earth shook under our feet with a 5.2 magnitude earthquake. And if you're like me , you may have heard it before. You felt it with a loud boom followed by the rattling of everything around. Well , thankfully there was no major damage and no injuries were reported. And though it was considered to be a moderate earthquake , it was the biggest we've had since 2010 and almost to the exact day. So why is this happening and what's happening next ? Here to talk about it is Alice Gabriel. She's a seismologist and associate professor at UCSD Scripps Institution of Oceanography. Welcome to midday edition. Hi.
S2: Hi. Thank you. Thanks for having me.
S1: So glad to have you on. So when there's this , an earthquake. I mean , we often hear about fault systems and fault lines. Can you explain what those are and why they shift ? Sure.
S2: Um , so California is actually earthquake country. So that's something that you hear often. And the reason for that is that we have many seismically active faults. So that means pre-existing weaknesses in Earth's crust that are collecting strain to the movement of tectonic plates. And from time to time , this strain that has been accumulating has to be released. And this has happened happening mostly very suddenly and in form of earthquakes.
S1:
S2: Um , this is actually something like a smaller sibling of the San Andreas Fault zone , which is this really dangerous , large , um , fault that we have a very close eye on. It's closer to our major population centers. It's actually closer to San Diego and Los Angeles. Um , and it's also one of the largest fault systems in Southern California and in historical times , East. Until yesterday , it has been one of the quietest in terms of earthquakes. Um , so the last , uh , historical event that was greater than a magnitude 5.2 happened in 1910 , and it's actually the only historical earthquake , um , of that size that we know of. So that was a magnitude six shock in 1910 , um , which produced no known surface rupture and did also little damage , just as the event yesterday.
S1: Um , well , the U.S. Geological Survey reports that this earthquake was a 5.2.
S2: So what we measure seismologist with the magnitude scale is actually the size of an earthquake based on the energy that it releases. And it's a little bit confusing because it's what we call a logarithmic scale. So that means that a magnitude six earthquake is really much larger than a magnitude five earthquake. So a shift from size five to size six and a magnitude scale means 32 times more energy being released. So a magnitude six event is not just a little bit bigger than a five , it's really much more powerful. So this is why we quantified the event yesterday as a magnitude 5.2 as moderate. It doesn't feel very big compared to more massive earthquakes that are possible in California. It feels more like a big truck passing by. Some tissues rattle or bottles fall off the shelves , but it's not expected to cause major damage or injuries.
S1: As to where a six might cause some major damage.
S2: That's right. Mhm. And that's what's also interesting. So I said it's it's a measure of the energy that's being released. But if you think about what it means underground , um it's still rupturing a fault. That's a few kilometers long and deep and it can move the ground by several centimeters. So it's something that's certainly , you know , sizable , but the energy that it releases is luckily not expected to cause major damage.
S1: Some people felt an aftershock yesterday. So what creates an aftershock ? Yeah.
S2: You had more than 100 aftershocks , actually , um , that we that we were able to record. Um , so this is actually really useful for seismologists because they help us to see what part of the fault system moved underground. They're basically lighting up all of the , um , all of the parts of the fault system that just slipped. So they're just small , smaller earthquakes that follow some nice statistics that we know well. And that allows us to produce aftershock forecasts. Um , just reacting to the sudden displacement that happened in a large event , and releasing some of the stress that has been moved around underground.
S1: Well , we've been pretty quiet so far after that , after those aftershocks. But could we experience any of them today ? Yes.
S2: Actually , it's certain that you will maybe not experience , but that we can measure aftershocks today. So there was actually last night or later in the afternoon , there was a macro 3.9 aftershock , which some , some people close to Julian felt. There's also a 7% chance of another equally sized earthquake of magnitude five , but these chances are decreasing over time. So the likelihood for large earthquakes decreases over time. And there's a very small chance that a larger earthquake will follow. But we are sure 100% sure that there will be earthquakes and aftershocks happening today.
S1: Yeah , because that is like a concern. Like , was this 5.2 a foreshock in any way ? Like , can we does this mean that there's a bigger one coming.
S2: So statistically , the chances are small that a bigger one is coming just after the event. Um , the USGS actually releases or released an aftershock forecast , which you can , which everyone can , can see online. And there's less than a 1% chance of a larger of a magnitude six event following. So the statistically the chance is low. Um , it can happen and we wouldn't know. We wouldn't be able to predict that outside of statistical likelihoods. Um , and we only know if an event is in a foreshock in retrospect and retrospective analysis. And actually , this event yesterday , this earthquake had some foreshocks. There was a small earthquake that was partially felt by some people , um , on Sunday back to 3.3. That happened just before the larger 5.2 on Monday. Hmm.
S1: Hmm. Very interesting. But at least that that does put a lot of people at ease. Um , you know , a lot of people wonder about tsunami risk after an earthquake. Is that something anyone should be concerned about ? Yeah.
S2: This is this is a really interesting question that I'm that I'm also hearing a lot. Um , so we do have an automatic tsunami alert system , but there's some there's some facts that everyone can can basically check immediately after an earthquake to decide if you should leave the beach or , you know , we should prepare for a tsunami that's following and that for this specific earthquake , um , this one occurred inland , so approximately 120 miles away from the Pacific Ocean. So this one would not cause a tsunami. Um , tsunamis are typically generated by undersea earthquakes. So that means the hypocenter or the star on the maps that has to be under the ocean and then cause significant vertical displacement of the ocean floor. Um , so this is what causes a tsunami besides some secondary sources that can be landslide induced. But this earthquake's epicenter was really far away from the ocean , so it didn't have the potential to displace the seawater , and therefore it didn't trigger a tsunami. So if you're curious about the tsunami risk of an earthquake , you just felt one of the easiest things to do is to check where this earthquake occurred and if it happened inland , there's no danger of a tsunami. So you can enjoy the day at the beach.
S1: Yeah , well that's good. Well , lastly , what's your advice for staying prepared and alert when it comes to earthquake warnings , especially since there's something that can't be forecast. Right.
S2: Right. So one of the most important pieces of advice that I can give is to make sure that you're subscribed to Shake Alerts. So we are lucky enough in Southern California and all of California , actually to have an operational earthquake early warning system that's called Shakealert. Um , if you have an Android device that will be automatically activated on your phone , but if it's an iPhone , you need to download an app. So , for example , the Shakealert app to be able to receive these warnings and and get information. For example , check , um , how deep the earthquake was , where it happened , did it happen offshore , underneath the ocean or inland. And what kind of aftershocks are we expecting ? So this is this is really a useful , easy to implement piece of advice because it can give you just a few seconds of warning to dive under your desk , you know , and drop , cover and hold on. And it's been again yesterday. It's been very successful. Lots of , um , lots of folks received a couple of seconds warning just before the shaking started.
S1: That's great. Well , I've been speaking with Alice Gabriel. She's a seismologist and associate professor at UCSD Scripps Institution of Oceanography. Alice , thanks for joining us and thanks for your insight.
S2: Thank you so much. It was a pleasure to talk to you.
S1: Coming up , the best ways to be prepared for an earthquake.
S3: I have a kit in my car. If I do get stranded , whether it's an earthquake or some other disaster that I have emergency water in , emergency food and some stuff to keep me warm in case something happens.
S1: Hear more when KPBS Midday Edition returns. Welcome back to KPBS Midday Edition I'm Jade Hindman. Though there were no reported injuries or major damage , yesterday's earthquake was a good reminder to be prepared because it's not a question of if , but when. So how should we get ready ? Well , my next guest , Jacob Margolis , says it's not as simple as making a go bag. So he's a science reporter for LAist public radio and host of the podcast The Big One Your Survival Guide. Jacob , welcome to Midday Edition.
S3: Thanks for having me.
S1: So glad to have you on here. All right. So I ran outside when the earthquake hit. Some people , though , hid under tables in their homes. What should we be thinking about when it comes to staying inside or going outside during an earthquake.
S3: Yeah , you should definitely have gotten under that under that desk. I would not recommend running or trying to run when there is an earthquake. If it is big enough , um , it's going to be impossible to run , uh , unless , you know , you're in a building that is going to collapse or you have a feeling you are like down in Mexico City. I know that given how bad earthquakes have been and how much building collapses they've had , how many they've had. Uh , people often do run outside and are encouraged to run outside , but here are seismic codes and are building quality in a lot of places. Is is much better. And so I would generally trust the buildings that I'm in , especially these days. I would get under that desk. If I'm at home , I make sure my bed , which is , you know , I feel like you're , you know , likely in bed when it hits for some reason , uh , is one of the safest places to be. So I tell my kids to just stay in bed. We'll come get you. Wait until the shaking is over.
S1: All right. What other places are safe inside of your home ? Uh.
S3: Doors can hit you and smash your fingers. Break your nose , what have you. Uh , you can go ahead and just get under a table. If it's a glass table , I obviously wouldn't get underneath it. If there's no table nearby. Uh , what I would try to do is probably squeeze up against a wall where you don't have a bunch of stuff hanging , hopefully. And this is the sort of thing that if to that answer , you then said to yourself , but I have stuff all over my home , I would say , maybe you should have a little place in each room that you know is safe to go when things start shaking. That's not more than a couple steps away.
S1: All right.
S3: Uh , make sudden , jerky movements where you're going to get into an accident , but you can gradually slow down. Uh , and , you know , I guess it depends on the size and exactly where you are. But I imagine other people will kind of slow down as well , and then everybody can get back up and move in fairly quickly. Yeah.
S1: Yeah. And tell me about this. You know , because we usually don't get any warning when earthquakes happen. I mean , sometimes an alert even comes after the shaking is well underway.
S3: So we're in Pasadena , up in Los Angeles around Los Angeles , and we got a , you know , our phones started blaring with the My Shake app. And then , like , you heard them across the newsroom and then the wireless emergency alert system went off , and that's like everybody's phone. You know , what you get for , um , for when there's like a , you know , someone's missing or something. Those kinds of alerts. And we essentially had 20s where I was sitting there with my colleague and I'm like , hmm , I wonder if we're going to feel the shaking because it's saying it's all the way down in San Diego. So I'm not sure where is it going to come ? Is it going to come ? And then sure enough , it did hit. Um , the reason that we know that those the reason we are able to predict those , uh , in any sort of capacity is there's a really big network early warning system that's installed , like across the west coast of the US. And so what happens is the sensors near where the earthquake , the epicenter is. So say down in around San Diego , uh , can actually pick up that shaking and send an alert to phones , hopefully faster than the shaking actually gets there. And so today was a really good example and it worked really well. If it is under a magnitude five earthquake , you might not get an alert. It depends. If you download the My Shake app you can set the alerts lower. Um , but if you didn't get an alert and you just it started shaking and then you got it. Odds are you're kind of probably too close to the shaking or the system messed up.
S1: Yeah , that's what that's what happened in my case. Like I was outside the door before I even got an alert. So it must have been because I was so close to it.
S3: Please have the following items. Water. One gallon of water per person per day. Because I have the space , I shoot for three weeks. The likelihood is that water systems will break or water will not be drinkable , as we've seen during the recent fires. Something can happen with that system. You need water to survive. If you have medication , make sure you have extra medication on hand. Delivery of medication as well as , you know , pharmacies potentially being opened if it's a really big earthquake. You know , all that stuff , the entire supply , the whole system is going to be in question. I have a little bit of cash on hand in case payment systems go down. And then obviously food is always a good option. A way to cook that food if you're feeling extra like a camp stove or something with just that , and then the normal stuff inside your house , you know , maybe you have a tent for camping to sleep outside if you don't feel safe inside. All that stuff would be would be good to have. I also have a kit in my car. If I do get stranded , whether it's an earthquake or some other disaster that I have , emergency water in , emergency food and some stuff to keep me warm in case something happens.
S1: But here's a question though , like because if an earthquake happens , a big a big one and the building that you're in is not structurally safe , say some things collapse.
S3: You can keep some of it in your closets. You can split it up. Maybe you have an office that's nearby that , you know , you can get to keep some in your office. The whole point of it is to. I think that's a really good question. Uh , the whole point is to make sure that it's accessible , at least for a period of time after the quake , when you don't have resources , nothing's going to be perfect , and a lot of people are really afraid to go back in their house after earthquakes. Understandably so. Stuff that's easy to move. Maybe not like giant 50 gallon drums. I just buy gallon bottles from like Smart and Final or Costco or whatever. Those are much easier to move. I could throw some in the car during an emergency. It's all good. So there. You don't have to go overboard with the prepper mentality. Just kind of at least have some water in your medicine.
S1: Um , you know , you've dedicated an entire podcast to surviving the big one. So is there any way of knowing when that catastrophic earthquake could hit us ? Nope.
S3: Could happen literally. By the time we're done with this interview , all you can do is prepare to the best of your ability , accept that it's going to happen , and believe in your preparation. Besides that , we just got to kind of kind of enjoy the ride and hopefully we all come out safe.
S1:
S3: Basically a 7.8 magnitude earthquake starting on the San Andreas Fault near the Salton Sea , uh , releasing essentially northward up the fault. Um , and that it was based on a big USGS study that they looked at the potential impacts and modeled it out. And some of the impacts that we saw were building collapses. Uh , we saw the likelihood is that the water system will be very damaged. The sewer system could be damaged. Um , we could see fires break out because gas lines break and then those catch on fire. We could see roads impassable because , for instance , the roads cross over the San Andreas and you literally get displacement on both sides. Like one part of the fault goes northward , the other one stays there or what have you. Uh , they they it'll actually split the road. So , you know , certain roads may be impassable as well. The bottom line , again , is that you need to be ready to survive on your own. I would say probably more than a few days just to be safe and feel comfortable. I prepare for three weeks. Um , it's not an apocalypse scenario. It's really like , hey , do I want to be standing in line waiting for water in a hundred degree heat in the San Fernando Valley here in Los Angeles ? I don't I just want to go to my garage and pull out some. Pull out some water to drink.
S1: Yeah , well , I mean , what kinds of structures are more vulnerable to damage ? Yeah.
S3: Brick buildings. Um , although we fixed unreinforced masonry is what they're called. We fixed a lot of those. I think most of those. I mean , I know definitely here in Los Angeles , I'm not sure about the rest of California. Uh , we have non ductile , um , non ductile , uh , concrete buildings as well , which uh , are basically unreinforced , uh , concrete. It's just essentially they're big concrete buildings that could , could uh , hypothetically , theoretically collapse. And then we have um , steel moment frame buildings , which are , which we have down here in Los Angeles , there are big skyscrapers sometimes. The Getty Center was a steel moment frame , and basically the welds that were , uh , used , um , at a certain point in construction , certain ways of joining steel beams. And basically when the 94 earthquake happened , there were some of these structures under construction. They were actually able to see that there were like cracks in the places where the steel structure was being joined. Those could also theoretically collapse. It would take a massive earthquake to do , to collapse a building. But even if a building didn't completely collapse , maybe it was slightly tilted to one side. You know , that's red tag. That's a lot to take down. That's a lot to , you know , you might not feel safe being in downtown LA after something like that happened. So the psychological impacts are real. The economic impacts are going to be very real as well. But there are good jillion different scenarios that could play out. We can't say for certain anything will collapse , but it is definitely possible.
S1: All right , so the minor earthquake that we had yesterday.
S3: Um , if you have giant cracks propagating that weren't there before , which aren't always inherently a sign of major issues like cracks do form normally in houses as the ground shifts and the thing settles and whatnot. But , um , you know , I would say kind of like when a landslide is going to happen , you can't really open , you know , doors are no longer plumb. Uh , you can't really open or close them. That that would be a pretty big concern to me. Uh , there is a lot of preventative measures that you can definitely take as a homeowner if you are in a single family home , including , um , you know , bolting and bracing your house if you're on a raised foundation is essentially adding plywood to , uh , underneath the house to , go ahead and secure it and keep it from falling over and falling off the foundation. And , um , yeah , I don't think it's phenomenally expensive. It's probably much cheaper than having to kind of redo your whole house once. Once that does happen in an earthquake. Yeah.
S1: Yeah. You know , a lot of us have young kids to think about and take care of during disasters.
S3: I , I with my kids , tell them what the science is. It's that the earth is under a lot of stress in certain places. And when that stress gets released , those waves travel through the earth just like sand waves through the air. And that is what we are feeling , that sort of shaking. There are things that we can do to prepare and be safe , that mommy and daddy have done those things , and that if there is an earthquake and you are in your room , stay in your bed. If you're somewhere else , get under a desk. I had a game that you can play that Doctor Lucy Jones , you know , earthquake. Uh. God , if you will. Earthquake extraordinaire. Um , has has , you know , said to me that I. That I do now is that anybody can call out earthquake at the dinner table. You get under the table , it sort of normalizes that whole process , um , with kids and you sort of turn it into play. And sure enough , when there was an earthquake warning , we got an earthquake warning. I was sitting there with them at the breakfast table , got a warning , said , okay , guys , earthquake ! We all just got under the table. It shook very lightly. I got out , I was like , you guys good there ? Like we're good. And I went to do my coverage. And so by normalizing it , talking about it more , that's my feeling. I'm not a childhood expert. I'm just a parent. Uh , my feeling is that , uh , you know , knowledge is power. And you can tell them it's going to be okay , even if it's scary. Yeah.
S1: Yeah. You know , you've been doing a lot of reporting on the aftermath of the LA wildfires that happened earlier this year.
S3: Like now , everybody's in the mess with insurance and not sure if they're still going to have , you know , they're out of their house. They're not sure if they're going to still have housing in a month , if they have to move back home to an area that's still pretty polluted with all sorts of problems. Um , clearly we don't prioritize. Uh , I would say helping individuals get back on their feet quite often , and they're sort of at the mercy of the private insurance system and their own. Uh , you know , you better have money to recover , because if you don't , you're in a really , really difficult situation. And that's the system that we've chosen here. Um , that's what we continue to propagate. And that is something that years that we put out the Big One podcast years ago , and that was our ultimate conclusion then. And to me it's the same conclusion now. How about a good note though. On a good note , I will say your neighbors want to help each other. And you will. You're likely to help your neighbor. They're likely to help you , at least for the short term. Now six eight months out , that's when I think it gets a little bit hairier.
S1: I've been speaking with Jacob Margolis. He's a science reporter for LA Public Radio and host of the podcast The Big One Your Survival Guide. Jacob , thank you so much.
S3: Thank you.
S1: That's our show for today. I'm your host , Jayde Hindman. Thanks for tuning in to Midday Edition. Be sure to have a great day on purpose , everyone.
