Transcript for What Makes a Seismologist Worry About California Quakes?
Is there a chance this is signaling the -- Ford -- -- one talk about going out of San Andreas now. The chance that this could trigger and bigger earthquake right here. Every earthquake has that chance 5% when it first happens by the time it three days after the earthquake the chances are almost completely gone. The chance that we are seeing a return to a higher level of activity and we should just expect another magnitude five within a year or so. That's actually pretty severe click was on a Little -- above the -- -- thrust we have these big faults. Like the San Andreas the -- tells the producer very biggest earthquakes are a little ones are on little -- second or fourth round. Appointed health thrust has earthquakes much less frequently that the San Andreas San Andreas -- -- -- Chris -- eight. Every 10050 years Puente hills has a seven and a half every 2500 years sounds like it should be better right. The problem is the Puente -- runs literally under downtown Los Angeles so when it happens it's probably the most damaging earthquake we can think about. And that's -- this one. At five point one it seems like everybody and their brother felt -- while that's right because being near to the fault. Really makes a difference the shaking -- off really rapidly. And if you're right on top of that we -- attacked buildings here in Pasadena not very far away yeah I felt it. But it wasn't much of anything. Imagine now instead of having a few kilometers a few couple mile long fault. Down Aaron Gray area we now have a forty mile long fault that extends all the way from -- at Hollywood. You can start seeing just what level of damage we can have. What are you worried at -- as it relates to this quake or is it that. You know an out of work couple days -- this one is likely over. This money is likely. Not going to be producing anything more damaging it will be producing more felt earthquakes and people will be surprised -- come and ask us. What do you mean we're still having aftershocks and they go well actually a precipitous collapse for a year. Com but it. But the bigger picture we are saying if if Los Angeles is returning to -- higher level. We've got to get ready. For a lot more earthquake -- earthquake response we need to be tried to grapple with all those things that we can reduce the losses because. Most earthquake damage is preventable. We recording -- -- and California for almost a hundred years that we seismic stations out. We're using new computers and more stations to determine what we've always determined. -- magnitude so quickly do we -- that information to two more distant sites before the shaking itself gets there. We're in a prototype mode we got a four seconds warning here in Pasadena for the earthquake in the hopper. And for the San Andreas earthquake we think we can get about 45 seconds warning. Forced very strong -- coming and the Los Angeles area. You know people there's a four seconds what -- -- good does that do what -- said. Automatic systems four seconds. Lets the elevator code at the nearest floor and opened the door. And -- the search and pulled a knife after chest before the shaking jerks his hand there's actually a lot of things that can be done. It they've been operating one of these systems in Japan since 2000 sap and and in the 2011 earthquake. No train derailed and -- Japan's because every train had come to a stop before the shaking got to a and that's what we wanna do for California. So clearly have an aftershock -- -- got four seconds warning here at Pasadena. Because it took probably about. Six to ten seconds forward. The waits to get from -- up here and we got information before the waves themselves and how much of a heads up did you get on the five point one. We got four seconds for the five point one. When we have this earthquake the big San Andreas earthquake that we expect to start. A long ways away from Los Angeles but cause a lot of shaking here we expect to get about 45 seconds warning for that -- And that's enough time to take some action that's a real activity to human beings can take. We think that the automatic actions like moving elevators to the -- for an opening that the -- stopping trains stopping hazardous material handling. A lot of manufacturing processes all of those automatic ones. Could greatly reduce or losses it's of this is sort of your nightmare scenario -- you keep it -- -- -- to remind yourself for what this is how best remembered this is the most common. Really bad earthquake. Because the San Andreas is the longest fault in California and at the length of the fault that determines the magnitude. This model lists for an earthquake that's 200 miles long. And therefore we have 200 miles of people that are literally on top of the earth quake and then and the -- last for -- seconds. And these waves then travel out. And as you watch them come into the LA basin they get trapped in the big bowl of jello that's the -- at the LA basin. And it just keeps on ringing and ringing and we estimate fifty seconds -- released on shaky in ally.
This transcript has been automatically generated and may not be 100% accurate.