Earthquake coverage: Magnitude 5.2 quake strikes Kern County, shaking felt across SoCal

Intro struck just a short time ago this evening we have reports of several aftershocks in the 2 to3 magnitude range this is a rather large earthquake 5.3 that is something you're going to feel we're about 90 miles south of Bakersfield and there are reports all across our area here in Los Angeles and the um surrounding spots that have felt it all the way down here those yellow spots there are earlier earthquakes much smaller you likely did not feel those but uh we want to hear from you if you did feel this earthquake tonight epicenter the city of Lamont just a short ways south of Bakersfield as always if you uh felt something like this if you um have a story to tell we would like to hear from you you can post to social media use the hash ABC7 eyewitness and we will be able to pick it up there you go 9.9 preliminary preliminarily you can see that magnitude 5.7 the numbers are a little off often times when these first happen and so now uh I believe they are calling it a 5.3 magnitude earthquake we are waiting word from Dr Lucy Jones one of the preeminent Scholars on um earthquakes and their After Effects and what we need to do to prepare for them and deal with him we are waiting to hear something from her as she is going to speak as she does most times after earthquakes in Southern California let's go right now to Chris Dr Lucy Jones Christie there is Dr Lucy Jones right there are we gonna listen in to Dr Jones I think that's worth it listen now not that long ago that I would have had to go into the lab and it would be a l at least a half an hour before you would have heard anything do we have more uh questions coming in maybe we can reiterate for folks that have joined since then um I know the earthquake was a considerable distance from LA so people are probably wondering why they felt it so strongly here in LA and maybe maybe Allan you can take this one you talked a little bit about the amplification in basins previously sure so there's a couple of different effects Lucy kind of mentioned so let me repeat the question the question is why am I feeling it even if I'm far away from the earthquake it was only a magnitude 5.3 uh magnitude 5.3 is still decent it's still a good size earthquake so we would expect to feel that the people close to it obviously look quite a bit more shaking um when we're farther away uh it's a little bit later at night now uh things are quieter and so it's easier to notice things moving around a bit more than if you're driving around in your car during the day and so you might be more sensitive that was kind of one thing Luc mentioned another effect is the Basin effects and so la is in a basin and so that can amplify shaking as well uh and so in the Great Valley also to the north of where the earthquake was um also uh had a lot more shaking kind of extending through the valley and so we can see that the the Basin effects also is one of the effects that that increases of shaking that you would otherwise normally have thank you Alan uh do any of our Questions other attendees have any questions for our seismologists I see a number of folks here from the media if any of you have questions please ask them in the Q&A function and we will answer them the other thing I would just point out is the USGS has a lot of nice tools uh for people who want more information they can go and look at to see that like what I'm talking about the effects of the shake and there's these Shake Maps they you can see uh another thing that you is uh really nice is they have the did you feel it so people can uh click on it and say what they felt exactly and then that will go to uh the information actually that uh is added to those products and you can see how other people felt as well on those tools so there's a number of tools there for this quick for all section and I realized I just now figured out how to set up the zoom tool Earthquake history so that you can see me and Allan as we respond to these questions um okay asking for a review of uh the earthquake history of this region um the most famous earthquake in this region was the Kern County earthquake in um July of 1952 it was also sometimes called the Tahachapi earthquake it was a uh led to a lot of changes in our earthquake policy because it did so much damage it did quite a bit of damage in Los Angeles Angeles even though it was up there it had a very large Aftershock that killed two people in Bakersfield so I think it's largest Aftershock was like 6.7 or something around that um so and before that earthquake had happened it was really quite a quiet region uh we saw continuing um uh activity in the region for decades in the 1980s we were still seeing uh a rate of earthquakes above what it had been before uh before the first earthquake had happened and that's our definition of aftershocks so those aftershocks um continued for 40 years um that earthquake was on the white wolf Vault but our preliminary results here uh suggest that this is not on the whitewolf fault and in fact uh the automatic analysis says it's most probably on a fault that we don't have in our database so we can't say this particular one we can't say it's very near the white wolf fault now the white wolf off was only recognized because of the 52 earthquake it broke through to the surface um this Earth You know a bigger earthquake happens over a larger fault surface so the bigger the earthquake is the more likely it is that you can actually see the fault it'll break all the way up to the surface this earthquake is small enough uh that it's unlikely that it's producing any sort of surface rupture and therefore we may never know exactly which fault it was on um uh it's is it yes how many unknown Faults Are there I have a question of is it common to have Quakes that are not on a known fault um uh Northridge was not on a known fault I would point out um so uh and in fact the smaller the earthquake is the the more likely it is we it's not a major fault I mean there we have lots of tiny little secondary features that haven't been um uh that aren't named and they'll have little earthquakes on them when we see like a magnitude 3 near the San Andreas fault it's not on the San Andreas it's on some secondary feature so most small earthquakes at this point are actually not on our big named faults um the transition to where you think it's much more likely to be on a named fault is around magnitude 5 and a half to six plenty of fives are on faults that we we don't know um so this is uh um not uh that uh um unusual to to see something like this um and as I said because it's 11 km deep and it's only a magnitude 5.3 a 5.3 is going to be a fault that's maybe a few kilometers across and if it starts at 11 km below the surface of the Earth it'll only get up to five or six kilometers below the surface and therefore we will never see something there um so uh um I know we we often talk about faults and the bigger earthquakes it's really significant the one thing I would say is when you think about oh what does it mean for the rest of us that doesn't change what depending on what the fault is you know all of Early warning system Southern California has lots of active faults and being on one particular fault doesn't say it's more likely to be setting off an earthquake on some other feature I know how much more you want to add to that Allan uh the only thing I was going to add is uh we often times get questions about why there's difference in the magnitude before we kind of settle on the final magnitude uh Shake alert the early warning system especially uses very little data uh so those to in order to get the warning out because uh we don't know when an earthquake is starting it's going to grow to a very large size earthquake uh and so they we try to get that warning out as quickly as possible to the um to people and then as the earthquake grows there can be updates um but to get that initial Earth that warning out it's only a few seconds of data and so with only just a few seconds of data you're trying to uh our automatic systems are trying to determine if that is going to grow into something bigger or get up that information as quickly as possible and so uh it might not have all the full information that we have once the all the the stations have detected and so it only with just four stations we start to seismic stations I should say the only detection the four locations uh we start to to put out those alerts uh and so as the earthquake grows and as the the seismic waves go out to more seismic stations then we can get a better estimation of actually what the real magnitude is so those early estimations are good they're still within you know that it was I saw a 5.7 came out of my phone uh and then we settled on now 5.3 looks like is the final but that was actually after a human came and reviewed it and so that that takes you know a few more steps to get to that um but it's still we weren't too far off with our automatic system so it's really great that we get that indidual value out there but then it takes time to get the the full data set to going all the across the the Wayfield across the entire State into all of our stations and then we can go back and look at it and say okay this is what really happened um but it takes a little bit more time to get to the full number and so those initial values that come out might be slightly different but it's still not bad we're still you know within 05 magnitude of what the actual value was so we're happy with that I'm gonna answer the next question Why does something feel like a rolling motion that's in here uh there's two of them actually uh Jennifer Pierce is asking about why why does something feel like a rolling motion uh that'll be included in my answer to the longer question from Ron Lynn which is we've heard of shaking being felt for 45 seconds in Los fiz and 20 seconds in South Pasadena in Los F someone felt at least three different waves one weak one strong and one weak in South Pasadena was two very distinct waves of shaking before the aftershocks began can you explain why the duration was so long okay so first the first large Aftershock which was a four and a half uh began only about 45 seconds after the main shock so I think the long duration in uh being reported in Los fiz is likely that the person felt um the a the biggest Aftershock as well as the main shock shock in terms of General duration right so the I'll put this the earthquake happens on a fault the fault is producing energy as long as one side is moving past the other it's sort of like a rupture front much like if I were to try and tear this piece of paper I don't do it this way that's too strong but if I start it at one location then I can rip down the paper and so the same thing happens on the fault it rips down the fault starting at the epicenter and moving down producing energy the whole way look at this you're hearing the sound the whole time I'm I'm ripping the paper so let's imagine 5.3 a fault maybe 5 kilometers across that means the Earth's producing energy for about 2 seconds and if you were very nearby you would feel an extremely strong motion for a few seconds because it comes off the fault and then it starts bouncing around off of things but if you're nearby there's not a lot of things that's run into when Allan said that we were having Basin effects amplifying the shaking that's the waves come into the Basin hit the walls of the Basin bounce back hit the next wall of the Basin boun back and you get a Reverb basically uh uh set up within the Basin and then you get this extended duration you know when we've modeled what the San Andreas earthquake would look like in the LA Basin we get 50 seconds of strong shaking in downtown Los Angeles and that's because of these Basin effects so this earthquake much much smaller of course but it was large enough to set up some of these Basin effects and get things bouncing around you know the very distinct waves uh if you there's the possibility that the P wve was felt here in the ba the Basin um the so an earthquake produces two different major types of waves the P wave moves faster but it's smaller the swave is a sheer wave and causes more damage as usually large quite a bit larger but it takes longer to get to us so sometimes you can feel the p-wave and the s-wave um maybe if somebody was in a very sensitive situation you would have one very weak one and then you feel the stronger one I know quite clearly that I only felt the strong one and it only lasted for about 3 seconds here in Pasadena um and I was sitting quietly on the first floor of a building so that where you're sitting you know if you're in a building the building might amplify what's going on what somebody perceives at any location uh is very variable depending on all sorts of situations of what your what uh soils what rocks the the waves went through and whether you're sitting still whether you're moving around all of those are going to affect it by quite a bit um okay um Ron also asked and you might pick this up Allan based on the shaking intensity do you expect that people on taller floors felt more intense shaking than people on Lower floors yes right you almost always the building itself moves so you you feel it stronger if you're on an upper floor um also you've worked a lot on urging cities to get vulnerable buildings to be retrofitted where do you think we are on that and has progress on retrofits been hindered by the pandemic um it's my standard answer is we're a lot better off than we used to be and not nearly as far along as we could be um I believe in the city of Los Angeles they've gotten a long ways on the software story retrofits um I I don't think it's complete yet but they're pretty far along it is supposed to be completed by now because that was a seven-year time frame but they are now going and catching the people who didn't do it um the in terms and the non-ductal concrete retrofits of course people had uh 25 years to get those accomplished it's now um four uh uh four uh excuse me nine years into the process um and um the uh um so I wouldn't expect actually that many to be done um I will also say that quite a few other um cities have moved forward on this and I'm personally rather encourage cage that's partly because um the you know the whole thing has always taken a long time we have several cities such as West Hollywood and Pasadena and Santa Monica that also passed retrofit as far as I can tell they're moving forward uh Torrance just passed something last year on softare story burbank's moving forward and um there's also Long Beach and Malibu are also trying to to do stuff as well so I don't feel like it's really come to a a screeching halt it's taking the time that government takes and every earthquake we have will probably remind people why they want to keep on doing this um the one thing we haven't made progress on yet is trying to build better buildings in the first place our current building code is what's called a Life Safety Code which is uh we will uh make sure you can crawl out alive but if the building's a total Financial loss well that was your choice to make and since people only build to what the minimum required by the code is that's all we ever end up doing and we are building in huge financial losses we know that it in the long run costs us more to build the weak building and then have to repair it later or tear it down we're going to probably have a lot of financial disruption because of this so I've personally been really trying to um encourage anyone who listen to move towards a standard that says uh have a building that can be repaired that having a completely destroyed building is too damaging to society and causes too much disruption and we're financially better off if we build a little stronger in the first place there's often a misperception that this would cost a lot of money the estimate is it adds about 1% to the cost of construction and then we don't have to tear the buildings down after the earthquake that however has not gotten through uh we we don't have uh um we haven't yet been able to get uh any laws passed that that encourage this I think it needs to be done at the state level rather than a local jurisdiction because it'd be too easy to decide to move a building elsewhere and Statewide really makes a lot more sense because it really isn't going to cost us a lot of money um thank you Lucy um we've had uh Fox 11 Earthquake overview joined since the last update so I'm wondering if you can provide an overview of the earthquake again for them or Alan whoever prefers sure I can do the do that again so we had a magnitude 5.3 uh earthquake that was um just uh 20 uh sorry 23 km Southwest of Lamont California uh which is at the southern end of the Great Valley um just a little ways north of Los Angeles uh so it was right near the grap Vine um it uh has produced now I see 31 aftershocks uh with the largest two just being over magnitude 4 there was a magnitude 4.5 and a magnitude 4 4.1 the magnitude 4.5 came um just um less than a minute after the main shock so it came in quick succession there the the first After Shock um and so uh it's been a healthy um Aftershock sequence although it's already dying down the last few earthquakes are really small now they're getting down to magnitude 2os and lower the back to uh to the point where most people probably not even feeling them um let's see there was a question about um the my shake it said a lot of people got the or the I'm sorry the shake alert a lot of people are getting the alerts for for it and can you explain why um the shake alert system specifically alerts um when the magnitude is high enough that's one factor and the other is if the is expecting shaping is high enough uh and so it's above a certain intensity and that's it's above intensity three um a while ago that intensity level was actually higher but then after the Ridge Crest earthquake um many people complained that it was actually too high and they wanted to get the alerts and so it was lowered at that point um but now so that's the the current level where the the shakings at but the this magnitude 5.1 was high enough to to get above the threshold for the magnitude and then if people are in within the certain area where the intensity is correct uh about that level intensity then they'll go ahead and get that alert also so a large re region actually felt that shaking and so a large reasion um got the I mean it was expected to feel the shaking so they got the alert for that expected intensity I'll I'll add an update to just uh as we said at the beginning like every earthquake in Southern California there's about a 5% chance that this earthquake could be followed by something larger uh and in the same location you don't see an earth a for shock isn't something that's you know over there and then set off an earthquake down in in La it would be some uh further earthquake would be in the same location um and that's of course a 95% chance that it won't be followed by something larger we are seeing as as Alan said a substantial Aftershock sequence with us and we would expect that to continue um the number dives off very rapidly with time um but actually the relative number of large to small stays the same so we're seeing now lots of small earthquakes having another three another four during the night would not be surprising at all uh almost certainly to have threes easily could have more fours um I think that's the most important thing to get in here uh we did say this does not appear to be associated with A Fault in in our database um having it on uh uh not previously mapped fault is relatively common it uh Northridge is our most obvious example of that happening um and uh uh so that is itself is not particularly concerning and also which fault it's on um um doesn't uh determine anything about its ability to trigger other events um I see another question from Ron Lynn about if this magnitude Quake had occurred in a highly populated part of Los Angeles would you expect to see a lot more damage of course uh we can look at what the intensities were as recorded on this earthquake so if you know that's all mapped up in the uh USGS earthquake uh website you can see um the the maximum intensity right near the main shock is is magnitude um 6 to7 and uh that's a level that throws plenty of stuff off of shelves could be doing some damage if you had an old an old brick building it's un very unlikely to really be damaging most of the structures that we have but we'd see a lot of damage to Interiors um with uh lots of uh you know damaged products in stores lots of dishes on the ground um probably not opening the refrigerators that usually takes intensity 7 um but uh we have a pretty large area of intensity six in the region if you put that into Hollywood um we would have been seeing a lot more damage of course the older buildings are more susceptible not particularly because they've aged badly but rather because the construction techniques that we used you know 80 100 years ago did not include seismic resilience as any of the principles um that's all of our open questions at this point um all right Alan and Lucy would you all like to take a short break or uh would you like to go ahead and end this if we have no additional questions coming in um I I think that ending it is probably we've uh we've been on for 45 minutes and hopefully people were able to get what they wanted okay that is Dr Lucy Recap Jones wrapping things up here clearly she feels like she has conveyed all the information that we need to know but let's recap what happened tonight at 909 a magnitude 5 uh initially 5.3 magnitude earthquake struck south of Bakersfield and about 15 about 10 miles south of the city of Lamont uh we have learned that that has since been now downgraded to a 5.2 magnitude Quake although I guess um at Caltech and Dr Jones had not gotten that information as of now because they were still going on 5.3 but 5.2 magnitude earthquake there is um really heavy Aftershock activity there were two as large as a f 4.5 and a 4.1 that 4.5 magnitude After Shock happened about 45 seconds after the main shock the main earthquake that everyone here in Los Angeles felt it in fact Dr Jones and Allen there talked about how people down in in Los Angeles in the LA Basin may have felt that 4.5 magnitude Aftershock as well so folks who said that this lasted for a minute or so were likely feeling the main quake and then that Aftershock which again upwards of 20 or more aftershocks and as Dr Jones just said if you if you heard her and if you did not she said there's always with every earthquake we feel here in Southern California there's a 5% chance this was simply a for shock which just means if a larger earthquake hits in the exact same spot that first 5.2 magnitude Quake turned out to be a fores shock to the main event which would be larger but of course as she also said that means there's a 95% chance that this was it let's head up to Chris Christie in air S as Los Angeles and the surrounding cities go into earthquake reaction mode uh Chris are you seeing anything from Air s all's pretty quiet up here in the Santa Clarita Valley jewry you're looking live at one of the closest suburbs to that epicenter up in Kern County as you make your way up the Grapevine things get very dark so we're staying in this area just kind of keeping an eye on any calls that come in now LA County Fire and LA City fire we have reached out to both of those agencies and both of them say that they have not received any reports of damage no structural damage at at this point no building collapses nothing like that yet but they are all in earthquake mode that means all of the trucks are out of the garages they have left the station and they are conducting uh what usually takes up to an hourong survey of their various districts across the city and across the county inspecting all of the critical infrastructure oil tanks water tanks uh in uh Interstate uh overpasses all of those kinds of things making sure there's no visual damage that needs to be attended to right away so that uh that uh initial shock as you mentioned happening about 45 minutes ago and they should be wrapping up that initial survey here in the next few minutes again as of now no reports of any damage Jory yeah good news there Chris I know this is felt from all over Marina del re New Hall Palmdale San Fernando down in Long Beach we've got calls to our Newsroom from folks there let's go now to someone on the ground who felt it here in the Los Angeles area and may have experienced something similar to what you felt tonight let's listen well we were sitting at Denny's and we were just sitting there and I just felt everything shaking and I said earthquake and then it just kept going did things move around nothing moved around nothing moved around it was just just the I felt the the seat shaking what was your reaction after that like what were your first thoughts like oh just like earthquake but it's just so natural you know we have them so much lately so I don't really it just happen you're still going about your day yeah we are different here in Southern California earthquakes for the most part don't freak us out too much this is a good barometer of uh how heavy an earthquake is this is from Josh Haskell's home our ABC7 eyewitness news reporter this is a light fixture hanging in his home he has used this exact light before in previous earthquakes not too much movement but just enough to know that something was going on out there we are of course 90 miles from the epicenter of this 5.2 magnitude earthquake just south of Baker field and it looks like right here you can see all of that seismic activity these are all the aftershocks being felt up in Kern County some of them making it a little lower uh further south than that as we were we were hearing there in that press conference with Dr Jones and uh member of the California seismology Department that because Los Angeles is in a basin it can amplify the reaction what we feel here and so even though we are so far away separated by some mountains um that is why you may have felt that down here that was uh from Alan Husker the manager of the Southern California seismic network uh we have a lot to get to tonight we're going to cover it all coming up at 11:00 again continue letting us know what you experienced here tonight and of course always a great time to make sure that you are prepared because the next one could be the big one prepare SoCal get a kit make a plan be informed we have tips that you can find and get you ready for when a major earthquake hits Southern California abc7.com SL prepare SoCal again we have have reporters fann out across our area looking for reaction looking for damage seeing what happened and talking to authorities about what might have gone wrong tonight and what might have gone uh right and so as we hit the 10 10:00 hour we're going to sign off here on our stream but again a magnitude 5.2 now earthquake hitting Southern California south of Bakersfield we could feel it here in the Los Angeles area but again we are going to uh do our due diligence here are reporting here and we'll have the very latest coming up at 11:00 here on ABC7 on our ABC7 Los Angeles app and streaming as always on abc7.com for now have a great night stay safe and of course let us know post to social media using the hash ABC7 eyewitness if you have any uh photos videos anecdotes stories anything we want to hear them send them to us and helps us get a bigger picture of what happened tonight and what you out there experienced across Southern California so uh let us know and we will report back to you at 11:00 on ABC7 have a great night see you in an hour