Path Home Shows 2010 Show Archive May 2010 Show 1018 Todd Halihan - Haiti Earthquake

Todd Halihan - Haiti Earthquake

We visit with Dr Todd Halihan, Geology Professor at Oklahoma State University, about the earthquake that hit Port-au-Prince, Haiti, earlier this year was just the first of several to rumble across the globe in recent months.
Todd Halihan - Haiti Earthquake

Todd Halihan

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Oklahoma State University

Show Dates

Show 1018: Interview with Todd Halihan

Air date: May 2, 2010



Rob:  Well the earthquake that hit Port-au-Prince, Haiti, earlier this year was just the first of several to rumble across the globe in recent months; but, is all this activity out of the ordinary?

Here to help us answer that question is Todd Halihan, an OSU Geology Professor that studies earthquakes around the globe.  Well when doing the research for this interview Todd, I just went to the Internet and I found the Iranian President blaming the earthquakes on immodest clothing on some Iranian women, I saw another website that said it’s the end of times.  What does a geologist say?

Todd Halihan:  Well it’s interesting because very very commonly it’s explained that if there’s a large earthquake that there’s something new that’s happening on the earth and that there’s the end of time coming or that there’s something that’s changed; but geologically, earthquakes are happening every single day.  And if you look at something like an eight or nine, a very large quake, that’s on average something that’s a once a year event; so, it is relatively rare, but it’s still every single year on average.  If you’re looking at something smaller like a seven, those are happening several times a year; so, if you said I think there’s going to be a seven or an eight that happens this year, you’re not predicting anything, you’re just explaining that the earth is still spinning around and doing its things that it always does.  If you’re looking at something small, like a five or below, those are every day events and so there’s websites that you can track where they’re happening and you could watch them happen.  And we keep track of the larger ones, where you might actually feel it or feel some damage, but if you were keeping track of every quake that happens, there’s millions happening and you’d be populating a website continually with all the little shaking that’s happening on the planet.  But once people see a big one that causes some fatalities, then the people are a little more atune to it and then around the world they watch them a little more closely until suddenly every earthquake becomes news and the world is ending, at least until we stop reporting on it.

Rob:  The 7.0 certainly got everyone’s attention in Haiti; why was that earthquake so bad?

Todd:  So that one was a little different in that earthquakes are happening around the globe, but you have to get one to line up underneath something to get the most shaking, and Port-au-Prince had two strikes against it.  One is that the earthquake was very, very close to it, it was very shallow, and so in terms of proximity the earth was shaking right near the city and right underneath it and so from that perspective you get a lot more damage.  The other bad problem they have is the building standards in Haiti were quite low and so economically they couldn’t build seismically stabilized homes and so they received a lot of damage.  You’ve had earthquakes that are much larger such as in Chile and in Seattle that really didn’t do that much damage because they built, everything built around the idea that they’re going to have the earthquakes.  Port-au-Prince knew they were going to have an earthquake at some point, and there actually was one segment that was prone and was predicted to be moving relatively soon, but they just did not have the economic capability to build their buildings according to those standards.

Rob:  Can we predict earthquakes?

Todd:  We can, we can’t predict earthquakes, and we’ve been trying for many years now, and every once in a while something comes out that says oh we’ve got a way to predict earthquakes.  And what people typically want is, they want a prediction that says next Tuesday at 5:00 this quake is going to happen at this location with this intensity; and that’s what people really love to have, it’d be a weather report similar to that.  But, it’s more similar for Oklahoma, it’s a lot like tornadoes in that we can tell you places that are more likely and if we have something going on we can tell you, you might want to watch out; but typically our window isn’t in the next few hours a storm’s coming; it’s this part of the fault might go within the next 30 years, which geologically is pretty quick.  But it’s a part that looks potentially more active over the next few years; and those percentages we get as high as saying something like 70 to 90 percent chance that in the next 20, 30 years, this segment might go.  But that’s about as accurate as we can get; we can’t do the next week at 5:00 we’re going to expect a 7.0 at this location.

Rob:  Well while my observations are far from scientific, it seems that I have seen more earthquakes here in Oklahoma, or at least reports of earthquakes here in Oklahoma, in the recent months than I can remember.

Todd:  And most of that is reporting; we’re reporting more earthquakes.  In terms of a location like Oklahoma, we typically don’t have the really big earthquakes that like happen in Haiti or Chile because we’re not on a plate boundary.  And so we’re not at a place where rocks are adjacent to each other that might be moving and typically your plate boundaries that might be moving back and forth like they are in San Francisco where one side is sliding past the other, you could have places where it’s slanting together like in Chile where one rock is going underneath another or you know where they’re pulling apart which is some of the Iceland which is erupting right now and you’re pulling apart the rocks and you have volcanism occurring, and earthquakes.  So, when you’re doing those movements, if you’re right there at the boundary, you get the most shaking and you get the largest earthquakes.  We’re not on one of those boundaries, so we do have some faults that are moving, but we tend to get, our biggest tend to be maybe a four or five would be some of the biggest thing we tend to get.  But, in Oklahoma we have another mechanism that is of concern when you produce fluids from the sub-surface, if you inject fluids, we’ve had cases in Oklahoma and other locations where if you over-inject fluids you can generate some small earthquakes.

Rob:  And that’s something that’s called fracking in the oil and gas industry, correct?

Todd:  You can be, you can be injecting to dispose of water or you can be injecting to frack materials in order to produce greater amounts of oil and gas.  But, typically what you try to do to make predictions and have understanding of, okay this scenario where we don’t want to get pressures too high in order to cause that sort of effect and we try to protect against it; but every once in a while you’ll get a small quake from something like that.

Rob:  And while we’re experiencing these small quakes, we’re not immune here in the middle of the United States from earthquakes, like the big one in 1800?

Todd:  Now, midcontinent we had a huge one in the early 1800s on one of the New Madrid faults and it did things like cause huge mud mounts along the Mississippi River; if you drive along there you can see some hills that were generated as mud squirted up out of the ground.  There were ports in the Mississippi River flowing backwards, and if it happened today, huge amounts of Memphis would be destroyed.  But the nice part is, we’re far enough onto bedrock that we would likely be a place that dealt with refugees from those areas and people that were displaced, but we likely would have our hospitals intact and could take care of those people if that happened.  The other large hazard if that happened today would be that all the communications pipelines for gas, oil, any water pipelines going across, any communication cables for the Internet, would likely be snapped or damaged; and so, it would be a huge change to the US if a similar quake happened today.  And so people have done a lot of planning in the midcontinent to try to deal with that, but there was a case back in the early 90s where somebody who had decent credentials, but no evidence, made a prediction of an earthquake on a particular day at a particular time along the New Madrid and it caused a huge panic, a lot of people bought earthquake insurance and a lot of schools closed and it was, it had nothing to do with science but it was somebody who had enough credentials that people reported on it and panicked the midcontinent US, at least places around the New Madrid fault, Missouri and Memphis areas.  And so you have to be very careful when you make a prediction like that, you have a lot of effects, and there was financially huge amount of effects for the area with no scientific basis for making a prediction like that.

Rob:  Alright, as always, appreciate you coming by, thank you Todd; Todd Halihan with OSU’s School of Geology.  And we continue our conversation on our website just go to and click on value added.