Did You Feel It?

A relatively rare East Coast earthquake centered in Virginia shook people from Canada to Georgia. Carnegie Institute of Washington geophysicist Diana Roman explains the geology of the region, and the factors that allowed the earthquake's seismic waves to travel far and wide.

Copyright © 2011 NPR. For personal, noncommercial use only. See Terms of Use. For other uses, prior permission required.

IRA FLATOW, host:

Up next, the quake. If you live on the East Coast, chances are you felt the earth move under your feet earlier this week. An historic 5.8 magnitude quake struck this side of the U.S. on Tuesday. The quake was centered in Virginia, but people reported feeling it as far north as Canada and all the way down into Georgia. Big quakes in this part of the country not at all uncommon. And last time, a quake hit this close to something this size in the area was 1875.

But when quakes do hit the East Coast, more people are feeling them over a wider area. Why is that? Well, here to answer some of those questions is Diana C. Roman. She is a geophysicist and a staff scientist in the Department of Terrestrial Magnetism at the Carnegie Institute in Washington. Welcome to SCIENCE FRIDAY, Dr. Roman.

Dr. DIANA C. ROMAN: Thank you.

FLATOW: We keep hearing that the reason why people felt this quake widespread because it was on a single plate, is that right?

ROMAN: Well, it's - it's what's known as an intraplate earthquake, meaning that it's an earthquake that happened very far away from one of the Earth's major tectonic plate boundaries. So here on the East Coast, we're not on a plate boundary. We're, in fact, very far away from the nearest plate boundary. And so that makes this earthquake somewhat unique, and that's also why it was somewhat surprising. We tend to feel earthquakes, more commonly, closer to plate boundaries.

FLATOW: So we're not on a fault line that's on a plate boundary. It's just the plate shaking of its own, nothing bumping into it, sliding under it, anything like that?

ROMAN: Well, you basically need two things for an earthquake. You need a plane of weakness, and that could be something like a fault embedded in the rock, and then, you need force on that plane to drive that sudden release of energy. And here on the East Coast, we do have faults in the rock that are left over from previous cycles of tectonic activity a long time ago. So millions of years ago, the East Coast was very much like the current West Coast in that it was the site of an active plate boundary. And so we do have faults left over from that time, that if they're under sufficient stress can slip and produce earthquakes, like the one we felt last Tuesday.

FLATOW: This is SCIENCE FRIDAY from NPR. I'm Ira Flatow talking with Dr. Diana C. Roman, a geophysicist. We're talking about the earthquake earlier that most of us felt. And would it be true to say that these are happening all the time, of this magnitude or little less, and this is just one that we happen to feel?

ROMAN: They are happening, certainly not of this magnitude, but there have been reports of smaller earthquakes on the East Coast in recent years. And also, historically, there have been large-magnitude earthquakes on the East Coast. Most recently, actually, in the Gulf of Mexico in 2006, there was a magnitude seven that was felt along the west coast of Florida. Further back in history, some very famous events, the 1883 earthquake in Charleston, South Carolina, was a 7.1, and that did actually quite a lot of damage and resulted in a number of fatalities.

So the large events are rare, as they are everywhere on Earth. The bigger the earthquake, the less frequently it occurs. And that's the same on the East Coast, but they're even more rare here. But we do also have small earthquakes occurring occasionally that we detect with seismic instrumentation on the East Coast, as well as on the West Coast.

FLATOW: 1-800-989-8255 is our number. You know, something that to my own personal view is really astounding, is that I remember back in 1985 we had an earthquake that I felt in - well, living in Connecticut, and we had a hurricane that same year...

(SOUNDBITE OF LAUGHTER)

FLATOW: ...off the coast.

ROMAN: It's history repeating itself.

FLATOW: How rare is this?

(SOUNDBITE OF LAUGHTER)

FLATOW: Again, right, do you remember the '85 quake?

ROMAN: I don't.

FLATOW: Or do you know about it?

ROMAN: I actually was - I was living in California then. So I was dealing with our own local seismicity, but that's an amazing coincidence. And certainly, you know, I think this week's earthquake and the hurricane that's now headed towards the East Coast are not related. So it's one of those funny coincidences.

FLATOW: Let me get a quick call in from Abu(ph) in Charlottesville. Hi. Welcome to SCIENCE FRIDAY.

ABU: Hello. How are you doing, Neal?

FLATOW: Hi there. This is Ira today. Go ahead.

ABU: Oh. Hi. How are you? I live in Charlottesville. I'm a little concerned because we are - I think this is the fourth aftershock since then and I work in the hospitals. And most of the time - in fact, one of these events was (unintelligible) all of a sudden (unintelligible) feeling the same tremor. I want to know exactly how long this is going to last, because just two nights ago I was laying in the bed, almost 1:30 in the morning, and I felt another one.

FLATOW: All right. Let me get - I have to cut you off because we're running out of time. Dr. Roman, any response on how long this will last?

ROMAN: Well, first of all, aftershocks are normal after earthquakes, and there was a fairly significant aftershock the other night at one in the morning that many people did feel. That was a magnitude 4.5. There have been a couple twos and threes as well. And the aftershocks are going to become less frequent as we get further and further away from Tuesday's earthquake. So you may still feel them, but they'll become...

FLATOW: All right.

ROMAN: ...less frequent as we move on.

FLATOW: Stay with us. We'll be right back with more questions for Dr. Roman. I'm Ira Flatow. This is SCIENCE FRIDAY from NPR.

(SOUNDBITE OF MUSIC)

FLATOW: You're listening to SCIENCE FRIDAY. I'm Ira Flatow. We're talking with Diana C. Roman. She's a geophysicist and staff scientist in the Department of Terrestrial Magnetism - whoo - at the Carnegie Institute of Washington - in Washington, D.C. Our number, 1-800-989-8255. You know, we always talk about budget cuts and things like this to research, basic research and especially what goes on with atmospheric and geomagnetic kinds of research. Do you think this quake is going to change possibly some priorities in Washington because it hit home, so to speak?

ROMAN: Well, possibly. And I mean, if there's an upside to Tuesday's quake, that it was big enough to get people's attention and remind everybody that, you know, earthquakes do happen, and we need to continue to study earthquakes on the East Coast. But, you know, it didn't do a huge amount of damage. I know that's no comfort to people who were, you know, planning to visit the King memorial. But, you know, relatively speaking, this wasn't a damaging earthquake. So, hopefully, this will raise awareness and help increase funding to study intraplate earthquakes.

FLATOW: Chris in Salt Lake. Hi. Welcome to SCIENCE FRIDAY.

CHRIS: Hi, Ira.

FLATOW: Hi there. Go ahead.

CHRIS: I was hoping to ask your guest about connections between earthquakes and fracking. I do know that fracking is literally creating fault lines in the ground and creating large spaces where the earth could move into. Earlier this week in Colorado, there was an unusual earthquake in the center of a lot of fracking activity. And I was hoping you two could talk about that for me. Thanks. I'll take my answer off the air.

FLATOW: Thank you. Yeah. We had other inquires about this. Is there any connection, Dr. Roman?

ROMAN: Well, fracking is a somewhat controversial process that is used to extract natural gases from the earth. Basically, it's done by pumping fluids into the ground to break up the rock and make it easier to get into all the little pockets of natural gas that are isolated, to help push them out. It does produce earthquakes. Most of the time, those are very small earthquakes, but occasionally, they are felt earthquakes. Recently, there was a swarm in Arkansas - felt earthquakes.

Also several decades ago in Colorado, there was some deep pumping that produced several sizable earthquakes. And this why fracking is controversial, because we don't know about the possibility of the fracking process to trigger a large earthquake. We tend to associate it with small earthquakes, but it is possible that, under the right conditions, we might get a larger earthquake.

FLATOW: Is anybody studying that possible relationship?

ROMAN: Yes. Of course, this is something that's definitely being studied and certainly...

FLATOW: By whom?

ROMAN: By seismologists, such as myself, both in academia and also within the oil and natural gas industry.

FLATOW: Well, because we'd like to - I'm glad to hear you're doing it because you're an independent researcher.

ROMAN: It is a process and a phenomenon that is certainly being discussed in light of some of the recent observations of seismicity related to fracking.

FLATOW: When you say there was a moderate or - what size are we talking about - a frack-related quake?

ROMAN: Well, most of the seismicity that's associated with fluid pumping into the ground is really small, magnitude three or less, and that's below the threshold of what you would be likely to feel. But there have been fours, fives that are thought to have been related to pumping of fluids underground, although, again, that's rarer than the smaller events, but it is possible.

FLATOW: And with the increase with fracking going around the country, we might see more of those events.

ROMAN: It is possible. Yes.

FLATOW: Yeah. And something that you're working on.

ROMAN: Mm-hmm.

FLATOW: Wow. And what would you - if you had - I'm going to give you the blank-check questions sometimes I give to scientists. If you had an unlimited amount of money you wanted to sink into your research, what would you like to study?

ROMAN: Oh. Well, actually, one of my main interests is the relationship between earthquakes and volcanic activity, and that's something where we always need more instruments and more money to get out to the places that we're interested in and put out our instruments. But I think in general, you know, the way we move forward in understanding natural processes is by getting more observations. And so really having more seismometers, having more computational power to process data is really what's going to help us understand some of these things and move our ability to explain and, ideally, forecast these events forward.

FLATOW: And hardware is usually the first that gets cut, though, in budgets.

ROMAN: It is, but, you know, it's - science is expensive, and that's the reality. You know, it's not only the instruments themselves but also the transportation, the labor, the maintenance and so on. So science is simply, by its nature, an expensive field, but that's what it takes if we do want to solve the problems that result from natural phenomena like earthquakes.

FLATOW: All right. Thank you very much. Very eloquent today. Nice to have a guest who is - can speak so well.

ROMAN: Oh, thank you.

FLATOW: You're very eloquent. Doctor Diana C. Roman, a geophysicist and staff scientist in the Department of Terrestrial Magnetism at Carnegie Institution of Washington in Washington, D.C. Yeah. Thanks. Have a safe weekend.

ROMAN: Thank you. My pleasure.

FLATOW: Tie down that lawn furniture.

Next, we're going to move on and talk about and talk about - we've been hearing stories this week about - speaking of the earthquake - about the animals who reacted to the quake before we humans did. Animal caretakers at the National Zoo say lemurs gave alarm calls, the flamingos huddled together, the panda - well, actually, the pandas didn't even seemed to notice. But joining me now to talk about more about it is my guest Brandie Smith. She is a senior curator at the Smithsonian's National Zoo. Welcome to SCIENCE FRIDAY.

BRANDIE SMITH: Hi. Thank you for having me.

FLATOW: Now, from what we hear, this is something almost predictable, that the - that animals do react to these events.

SMITH: Well, I mean, animals are so incredibly sensitive to their environments. They have to be. So the fact that they can sense something of this magnitude coming, you know, seconds or minutes before we can, I don't think that's surprising to many of us.

FLATOW: It isn't, because you work with them and you see this.

SMITH: Mm-hmm.

FLATOW: Give us some idea of what struck you the most, that you knew, you know, some unusual activity was happening.

SMITH: Well, I think a lot of it, you know, a lot of the animals did things seconds before we felt it, especially the flamingos. The flamingos began to huddle together. The gorillas headed for the trees. One of my favorite stories is that Mandara, the mother gorilla, her baby who's a little over 2 years old, was away from her and she actually gave an alarm call a few seconds before. The first thing she did was grab her baby and then run for the top of the trees. And then the lemurs, actually, the lemurs gave a warning. They began sending out alarm calls about 15 minutes before the earthquake struck.

FLATOW: 15 minutes.

SMITH: Mm-hmm.

FLATOW: Wow.

SMITH: Well - and we actually noticed that - and this is earthquake happened during the day, so we weren't - we didn't see a lot of - we didn't necessarily see our animals beforehand. We weren't anticipating that something would happen, but we do know from the earthquake that happened last year that our elephants - actually, about 15 minutes before that, it was about 15 to 20 minutes before, our elephants started acting strangely. So they had their ears up, their tail up, they were in alert, listening posture. So we know that that happened with the elephants as well.

FLATOW: Isn't there any way - I mean, this is - you know, in science, they would say this is anecdotal evidence, right? They might be considered a coincidence. They're not - you know, they're, you know, looking at it, there's no experiment going on. Is there any kind of study you could do to try to test for this scientifically?

SMITH: You know, the hard thing of doing the study has to be something that you can replicate, so it's really hard to create an earthquake in a laboratory condition. So that's - the difficulty with this is that a lot of times as we go, we look at the earthquake when it happened and we gather that information in hindsight.

One of the great things about having animals in a zoo is that we can learn from them, so our - one of our primary goals is learning more about them so we can understand them better, so we can help save them and conserve them. So something like this is a really great opportunity for us to go back. So as soon as the earthquake went past, the first thing we did was say, what happened with your animals? What did you notice before, during and after the earthquake?

FLATOW: Mm-hmm. 1-800-989-8255 is our number, if you like to call and talk about the animals at the zoo. Or you can tweet us @scifri, @-S-C-I-F-R-I and talk to us that way.

The elephants. There are some elephants that - you say there are some evidence that the elephants moved before the tsunami, if I remember correctly. They also knew something was happening.

SMITH: Well, there was - in 2000, there were some anecdotal evidence of elephants. Some people said that they saw elephants moving toward higher ground before the tsunami. One thing that we do - we have an extensive research program in Asia, studying Asian elephants and some of our elephants are radio-collared. So we actually have collars on our - we have collars on our elephants in Asia, so what we're able to do is to go back and to look and say, where did they move before and during the tsunami?

We have an incredibly small sample size, so, like, we just had two elephants that were collared that we were able to look at, and we did not find any evidence that those elephants, those two elephants moving toward higher ground during that time. We actually found that one of our elephants actually moved slightly closer to the shore just before the tsunami, although she did move away afterwards.

FLATOW: You know, there are - we always look back on earthquakes and things. There are cameras that were either security cameras turned on in banks, whatever, capturing the shaking the ground. Where there any such things like that in zoo, that you could look at the tape and see the animals moving or making sounds that would actually document what they did?

SMITH: Well, we're going through now and we're looking to see - we have webcams on a lot of our animals, so we're looking to see if we have any video footage. But the thing is, not only do we need the video, but we also need a time stamp video. So we're not finding that we have that, you know. But a lot of - we watch our animals for a specific behaviors. We record these behaviors usually in response to a certain stimulus. And again, if - wouldn't it be great if we knew the earthquake was coming, and then we could have been ready to watch what they did before and during.

FLATOW: Let me go to the phones, to Constance(ph) in Longmont, Colorado. Hi, Constance.

CONSTANCE: Hi, Ira. Thanks for having me on.

FLATOW: You're welcome. Go ahead.

CONSTANCE: In 1989, I was an emergency planner out in California, living in Sacramento. And 45 minutes before the Loma Prieta quake hit, the dogs in my neighborhood all began to howl really loud, and I was quite aware that this was weird. And 45 minutes later, I could feel the shaking. And right away, I was pretty sure that we had a Bay Area quake, partially because of knowing that animals reacted that way.

FLATOW: Wow. Wow. Thanks for telling us about that.

SMITH: Well, you know, that's a great comment. One thing that we did - actually, some of our keepers were walking on one of our exhibits, Asia Trail, and a lot of the people outdoor in that - outdoors in that area did not actually feel the quake, but they were walking and they heard the elephants making some unusual vocalizations. And then they heard - then they saw some of the trees shaking, some of the bushes shaking. And so a lot of us were wondering when the earthquake hit, we were - you know, is it the jet? Is it the truck? What could it be? But we almost did the same thing.

You know, the animals - we were kind of listening to our animals and saying, what are they doing right now? And then when the ground started to move and we saw the bushes started to shake, we were able to piece it together a little quicker simply because we were reacting to our animals.

FLATOW: Mm-hmm. Would you be collecting all this data and possibly publishing it somewhere or...

SMITH: Yeah, that is one of our goals, so that is definitely one of our goals, to gather this. And even if it is just this anecdotal evidence, the more of it that we can gather, you know, as we gather this and put it forward, then we have more of a - it's more based in science rather than in, you know, kind of stories.

FLATOW: Well, thank you very much for - we're going to look forward to that report.

SMITH: All right.

FLATOW: Thanks for coming on and telling us about it and have a good weekend.

SMITH: You're welcome, you too.

FLATOW: Brandie Smith is senior curator at the Smithsonian's National Zoo, and she was talking to us from the zoo. I'm Ira Flatow. This is SCIENCE FRIDAY from NPR.

Copyright © 2011 NPR. All rights reserved. No quotes from the materials contained herein may be used in any media without attribution to NPR. This transcript is provided for personal, noncommercial use only, pursuant to our Terms of Use. Any other use requires NPR's prior permission. Visit our permissions page for further information.

NPR transcripts are created on a rush deadline by a contractor for NPR, and accuracy and availability may vary. This text may not be in its final form and may be updated or revised in the future. Please be aware that the authoritative record of NPR's programming is the audio.

Comments

 

Please keep your community civil. All comments must follow the NPR.org Community rules and terms of use, and will be moderated prior to posting. NPR reserves the right to use the comments we receive, in whole or in part, and to use the commenter's name and location, in any medium. See also the Terms of Use, Privacy Policy and Community FAQ.