How Scientists Predict Where Earthquakes Will Strike Next

11:32 minutes

a map of turkey showing dozens of yellow and orange circles, representing earthquakes and aftershocks as of early february 2023
A map of aftershocks above M4.5+ in Turkey as of February 6, 2023. Credit: Shutterstock

The pair of earthquakes that hit Turkey and Syria this week left the region grappling with death and destruction. Despite the region being seismically active, this particular area hadn’t seen an earthquake of this size for decades.

There are ways of knowing where the next big earthquakes will happen—but not when. Scientists use knowledge of fault lines and historical data to make their predictions, but saving areas from mass casualties often relies on infrastructure policies. Building codes that prioritize strong buildings can save lives, but older structures remain vulnerable. 

Across the globe, in California, the health impacts of electric vehicles are beginning to be seen. A study published this month finds that for every 20 EVs in a zip code, asthma-related visits to the emergency room drop by 3.2%. This is a striking number for a technology that’s just now becoming more commonplace. 

Joining Ira to talk about these stories and more is Umair Irfan, staff writer at Vox, based in Washington, D.C.

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Segment Guests

Umair Irfan

Umair Irfan is a senior correspondent at Vox, based in Washington, D.C.

Segment Transcript

IRA FLATOW: That pair of earthquakes that hit Turkey and Syria this week left the region devastated. And despite being seismically active, these are the largest earthquakes the region has experienced in decades. There are ways to know where the next big earthquake might happen but not when.

Joining me today to talk about the science of this story and others from the week is Umair Irfan, science writer at Vox based in Washington. Welcome back to the show.

UMAIR IRFAN: Thanks for having me back.

IRA FLATOW: Nice to have you. OK, let’s talk about these earthquakes. Was there any warning that they were going to happen?

UMAIR IRFAN: In the short term, no. There wasn’t really any sign. People in the region didn’t get any kinds of alerts when this happened. And the earthquake struck very early in the morning, so a lot of people were asleep at home when this happened. And that’s part of why the devastating toll has been so high.

But this is a region that’s known for being seismically active. There’s actually two major fault lines that run through Turkey. And this is an area that historically has had major earthquakes, but, as you noted, it hasn’t had a major earthquake in this specific region for decades. And so the challenge here is trying to come up with a probability and actually telling people how to respond and prepare for this. And that’s a problem that we face all over the world when it comes to earthquake risks.

IRA FLATOW: Because we know where the fault lines are. We just don’t know when the fault lines are going to break or move.

UMAIR IRFAN: Right. I mean, there are some very early signs in that you can get over very short term. Like, for instance, we know that earthquake waves travel over a period of time. And sometimes you can send, in some parts of the world, text message alerts to people hundreds of miles away.

But that only buys you a few minutes. And if you’re near the epicenter, you basically have very little to no warning. And that’s where you see some of the worst devastation.

IRA FLATOW: Mm-hmm. And the earthquakes were designated 7.8, 7.7. Remind us what these numbers mean.

UMAIR IRFAN: Right. So this is a logarithmic scale that measures the intensity of these earthquakes. The old-fashioned way was using something called the Richter scale, which you may have heard of.

IRA FLATOW: Oh, yeah.

UMAIR IRFAN: That was basically a scale that was calibrated to Southern California where it was developed. And scientists found that, actually, it wasn’t very good at describing earthquakes in other parts of the world. And so what they developed instead was a scale called moment magnitude, which, like the Richter scale, is also logarithmic, which means that each number going up represents a 10-fold increase. So a magnitude 7 is 10 times more severe than a magnitude 6.

But what it does is it also captures different kinds of geology and the different kinds of waves that can travel. For instance, in very hard rock, earthquakes can travel for a very long distance very quickly. But in softer soils and softer geology, that can actually attenuate. That can actually act as like a shock absorber. And so what this scale does is it allows you to make more apples to apples comparisons between earthquakes in different parts of the world.

Now, this is still not always that useful as a scale for architects and engineers who are designing buildings and trying to build structures to resist earthquakes. They’re often more interested in peak ground acceleration, which basically measures how fast the ground is moving in a given earthquake, or displacement, which is basically the total amount the ground can shift during an earthquake. And those are sometimes the more relevant ways of measuring the intensity of these kinds of events.

IRA FLATOW: And more useful. Let’s move on to your next story, which involves this week’s State of the Union address. President Biden mentioned cancer 13 times, which I think may have been surprising to a lot of people. And just a little reminder, a bit over 50 years ago, I think it was last fall, President Nixon declared a war on cancer. And President Biden mentioned two cancer initiatives. Let’s talk about those.

UMAIR IRFAN: Right. So President Biden has had a personal interest in cancer. His son died of brain cancer back in 2015. And when he was vice president under President Obama, Biden was put in charge of this Cancer Moonshot Initiative. And the idea was that this was going to be a go-for-broke push to try to resolve and deal with cancer as we know it.

Now, the reason why he brought it up in the State of the Union is that the funding for that particular program is slated to run out later this year, and he needs Congress to approve more funding for this. And so the idea is that more research dollars going into this that we have a better chance of making cancer a disease that people can live with. And they’re not necessarily talking about a cure here. The goal post is that they want to reduce the cancer death rate by 50% over the next 25 years. And so this is not necessarily going to make it a way to get rid of cancer entirely, but we’re talking about making it a more survivable, maybe a chronic illness.

And so the other program he was talking about in the State of the Union was this thing called ARPA-H. This is a subsidiary or a part of the Moonshot program, but this is a research initiative modeled on DARPA, which was the Defense Department’s Advanced Research Project Agency. And this was the program that led to the stealth bomber and led to the creation of the internet as we know it.

And the idea is that the government wants to fund a very high risk but high reward project, so things that are kind of off the wall, things we don’t know will work. And we’re going to expect that a lot of these projects will fail. But if one does succeed, we expect immense benefits. The problem is, of course, something like this is going to be very expensive. Congress thus far has funded ARPA-H to about the tune of $2.5 billion last year. But the White House wants to actually triple that money.

IRA FLATOW: Yeah, because we’re seeing some drugs that are hundreds of thousands of dollars a year for some cancer patients.

UMAIR IRFAN: That’s right. We’re seeing a lot of diminishing returns with cancer treatments that, first of all, a lot of these drugs are very expensive so the people who need them can’t always get them. And while they are making improvements, we’re paying a lot for these very marginal improvements. And so what we really want is a breakthrough that can actually move the needle.

IRA FLATOW: Well, let’s hope that happens this time around. Let’s talk now about electric vehicles, one of my favorite topics. If you’re a listener to the show, you know that. You have a new story about how EVs are saving lives, and we’re not talking this time about driving accidents. Tell me about what you’re talking about.

UMAIR IRFAN: Right. Electric vehicles, they don’t have an internal combustion engine inside them. They’re not burning fuel, so they’re not producing all these combustion byproducts, things like nitrogen oxides, carbon monoxide, all these chemicals that can actually make it difficult to breathe and lead to other kinds of health problems. So it makes sense that you would see improvements in air quality.

But what was surprising about this finding from this team of researchers at the University of Southern California was that it didn’t take very many EVs to actually start seeing these effects. And so what they did was they looked at real-world data in California– you know California has been ahead of the curve in EV adoption– and what they were doing was they tracked EV penetration across different ZIP codes in California and they measured that alongside emergency room visits due to asthma. And what they found was that for every 20 EVs per 1,000 people, there was a 3.2% reduction in asthma-related ER visits.

IRA FLATOW: So it doesn’t take many EVs, is what you’re saying, for that difference to come.

UMAIR IRFAN: I mean, it kind of signaled just how bad air pollution is. But at the same time, though, what they also found was that there was a big discrepancy in the areas that saw the benefits. EVs generally are a little bit more expensive. The average car in the US, new car, costs about $48,000. The average new EV costs $66,000.

And so wealthier areas were seeing the bigger declines in these asthma-related visits. But poorer areas are often the areas that have worse air quality. And so the dividends for this would actually be better spent in some of the low-income areas. And so it kind of signals to policymakers that we need a way to help ensure that those communities are also benefiting from this transition to cleaner vehicles.

IRA FLATOW: Well, one way we could hope that these new Biden tax credits for electric car purchases might make them more accessible to more people.

UMAIR IRFAN: Yeah, that’s something that Biden talked about during the State of the Union address as well.

IRA FLATOW: Yeah. Yeah. Speaking of carbon emissions, let’s go to your next story, which is about carbon capture, specifically from smokestacks. That seems pretty logical, right?

UMAIR IRFAN: It does. If we’re worried about carbon dioxide, why not go straight to the source and capture it there? And that’s something that scientists have been trying to do for a very long time. But the process that we have for doing that is actually fairly expensive and energy intensive.

We do CO2 scrubbing inside closed environments like submarines and spacecraft. But to do this on a power plant, the big issue is the economics of it. It gets really expensive. So the conventional technique is using these chemicals called amines, and they require reheating the chemical in order to regenerate it.

And that process can actually eat up upward of 30% of power from the power plant. This is called a parasitic load. And that adds to the cost. And so the capture cost ends up being about $200 per ton. And electricity in the United States, it’s sold on competitive markets in most of the countries.

And so if a power plant were to install this system, it would raise their operating costs quite a bit, and they would be noncompetitive. And so the big threshold or the big goal post here is trying to make this a lot cheaper and a lot more energy efficient. And a team of researchers at the Pacific Northwest National Laboratory said that they found a way to do that. They can actually now bring the cost roughly to about $40 per metric ton of CO2 from $200.

IRA FLATOW: By doing what?

UMAIR IRFAN: Well, what they found were these new types of CO2 binding liquids. So the problem with the conventional amines is that they also tend to absorb a lot of water, and you have to use a lot of heat to get rid of that water and regenerate it. But these CO2 binding liquids that they found don’t absorb that much water. They don’t require anywhere near as much heat to reproduce and regenerate.

And that means that the overall cost and the efficiency of the system goes down quite a bit. But they still capture about 90% or 97% of the CO2. And critically for policymakers, this is below the social cost of carbon that’s been established by the government. The government sets that cost at about $51 per ton. So if you can do that at about $40 per ton, then this becomes sort of a no-brainer if there is a carbon price that’s ever imposed.

IRA FLATOW: Not just for this government, but for other poorer nations.

UMAIR IRFAN: Right. Coal power plants in the US are already declining. But in much of the world, 80% of the world’s energy still comes from fossil fuels. And a lot of developing countries are still relying on fossil fuels to [INAUDIBLE] poverty, so that’ll get you there.

IRA FLATOW: Speaking of a water method, that goes right into my next story and my wheelhouse about surprising stuff about nature. And this one is about a new type of ice, ice that forms when you shake it really hard. This is really cool, so to speak.

UMAIR IRFAN: Yeah, it’s something right out of a science fiction novel. I don’t know if you’ve read Kurt Vonnegut’s Cat’s Cradle, but that was a big plot element in that story. But, yeah, what they found was that if they chilled water– these team of researchers in the UK, they chilled water to minus 380 degrees Fahrenheit, and they shook it in this container with steel balls.

Cocktail shaker is kind of on the right track, but you’d have to be shaking it really vigorously. They were shaking this at about 20 times per second. And what they found was that it actually created a new form of ice. And what was special about it is that ice typically forms crystals. And when it forms that crystal structure, it’s less dense than water, and that’s why ice floats.

But when they shook it with these steel balls, what they found was that it actually had roughly the same density as water. So this is ice that doesn’t float but is actually kind of neutrally buoyant. And also, it doesn’t form a crystal structure. It’s more like glass than it is [INAUDIBLE].

IRA FLATOW: That’s cool. That is really cool. It’s a great way to end your segment. Thank you, Umair, for taking time to be with us today.

UMAIR IRFAN: My pleasure. Thanks for having me.

IRA FLATOW: Umair Irfan, science writer at Vox based in Washington.

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