Interview with earthquake expert Lucy Jones

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Lucy Jones with the U.S. Geological Survey

Lucy Jones with the U.S. Geological Survey

Earthquake scientist Lucy Jones was tapped earlier this week to lead Los Angeles in its effort to make the city safer when it comes to earthquake issues. KCRW’s Avishay Artsy caught up with Jones to ask her a bit about what we know, and don’t know about the temblors.

Jones was in LA, when the Northridge quake struck  in 1994 and remembers the shaking.

KCRW: In your mind, were you going through the checklist of what to do, what was going through your mind?

Lucy Jones: The minute I was conscious I started counting, because the duration of the earthquake tells you how big it is. So I felt 6 seconds of strong shaking and thought, ‘this is only about a magnitude 6.’ It was on the low side, because Northridge was particularly intense, it was a short duration for its size compared to the average.

KCRW: Why wasn’t it as big as the Big One?

Jones: This wasn’t that big an earthquake. It’s a 6.7 the fault, it was 10 miles long and it lasted for 7 seconds. By contrast, the San Andreas earthquake that we consider likely would be about a 200 mile long fault, it would last for a hundred seconds. And we’d have something like 10 million people getting the strong shaking.

KCRW: Do you feel that we’ve improved our ability to predict the outcome of future quakes?

Jones: We’ve done a great job in telling you what the earthquake will be like if a particular fault will go. We understand the faults better, we understand the wave propagation much better. We have large computer simulations that have given us a really good picture, and a lot of this is the result of the Northridge earthquake and all the research that happened because of it. What we don’t have is the ability to predict the time at which a particular fault will go and as far as we can tell, that may be  fundamentally unpredictable.

We have fifty earthquakes every day in California. What we’re trying to predict is what’s different about a big one. And as far as we can tell, the big and the small ones start the same way.

KCRW: So there’s no way to predict which ones are big?

Jones: There’s no way at this point to know, and that information may not even be in the earth before the earthquake begins. It may be determined dynamically during the earthquake and if that’s true we will have proven earthquake prediction impossible. We don’t know that yet. That’s why we’re working on fundamental earthquake physics.

KCRW: The best thing we have now is expanding the earthquake warning system?

Jones: We can’t tell you before the earthquake begins, but earthquakes take a long time to happen, but if we can determine the earthquake has begun and send that message at the speed of light we can get that message to you before the waves get to you at the speed of sound.