Earth and Planetary Science
EPS Atmosphere, Oceans, and Climate

Reaching for the Stars

Friday, October 19, 2018

UC Berkeley geophysicist Michael Manga is leveraging Big Data and Earth science to explore whether there is life elsewhere in our solar system.

By Michael Peltz

Michael Manga always wanted to be a scientist. The Canadian native was just six when he started attending Macoun Field Club events at the National Museum of Natural Sciences in Ottawa. By high school, he was spending Friday afternoons with the club and publishing scientific articles. “At the time, I was way too naive and ignorant, really, to know how important that was,” says Manga, who has a BS in geophysics from McGill University and a Ph.D. in Earth and planetary sciences from Harvard University.

Today, Manga is a Professor of Earth and Planetary Science at the University of California, Berkeley, and one of the world’s foremost authorities on volcanoes and earthquakes. He has published more than 250 papers in peer-reviewed journals, on topics ranging from fluid mechanics and mantle flow to properties of magmas and planetary science. Manga co-authored a research article published in the May issue of Nature arguing that volcanic eruptions on Mars billions of years ago altered the atmosphere of the planet sufficiently to allow liquid water to exist on its surface, resulting in large oceans. The paper, like most of Manga’s work, relies heavily on math and data analysis. As a geophysicist, Manga tries to understand quantitatively how Earth works. The 50-year-old researcher integrates observations and field data with theoretical and model results; this often requires him to come up with new approaches in fluid and applied mechanics.

Manga has long been recognized for his work in the classroom. In 1999, as an assistant professor at the University of Oregon, he received the Ersted Award for Distinguished Teaching, established to “honor faculty members who have demonstrated early career excellence.” He moved to Berkeley two years later, and in 2005 he received a $500,000 fellowship from the MacArthur Foundation — often referred to as a “genius grant,” given annually to 20 to 30 individuals across a variety of fields who have demonstrated “exceptional creativity in their work and the prospect for still more in the future.” Most recently, in 2017, Manga was one of five Berkeley professors to receive the school’s prestigious Distinguished Teaching Award. “Of all the things I’ve done, I think that’s the one I’m most proud of, because it’s a big deal at Berkeley,” he says. “We take our teaching responsibilities very seriously.”

This summer, after completing a four-week geology field camp for Berkeley students, Manga spoke with WorldQuant Global Head of Content Michael Peltz about Big Data, Earth science, geophysics and the search to find life elsewhere in our solar system.

Are there similarities between geophysics and finance when it comes to using math, computers and Big Data to try to predict things?

Michael Manga: Absolutely. As physicists, we solve partial differential equations and we take advantage of all the data we have access to. When we work on planetary problems, like understanding Mars or the ocean worlds in the outer solar system, we have tremendous amounts of data. In fact, now on Earth we have huge amounts of data, too. And we can take advantage of all that data to do data mining or try machine learning. But at the same time, we also just solve equations, and we probably use algorithms for solving equations that are mathematically similar to yours. I bet you guys solve the equations better and faster than I do, though.

How has the exponential growth in computing power over the past 20-plus years changed what you do?

In 1994, my Ph.D. dissertation was basically to develop a numerical method for solving problems where we have interfaces that move around. We didn’t really do parallel computing back then, so I would monopolize every work station I could and then run one version of what I wanted to do on each one of those computers. Now we can get answers much, much faster. I do worry that we can get away with being sloppier than we used to, as well. I did spend a lot of time trying to figure out how to optimize what I did and develop approximations for certain expressions, which I no longer need to do because computers are so fast. What used to take overnight to analyze I could probably do in just a couple of seconds now.

But I guess, at the same time, that means it’s much easier now to focus on why you’re doing that computation — the application and the science — as opposed to being obsessed about how to optimize an algorithm or an approach.

Michael Manga-for-web 2.jpg

UC Berkeley Earth and Planetary Science Professor Michael Manga

Do you use machine learning?

We have for a couple of projects, yes. A specific problem we were interested in studying is what happens after big earthquakes. We see all kinds of changes in the earth and how much water is flowing in rivers: Wells go crazy; water levels go up and down. We were trying to identify patterns and correlations in these observations. We have lots of data, and we can use machine learning techniques to try to identify patterns that allow us to probe the physics behind what’s happening.

Is it helpful to have a deep knowledge of fluid mechanics when studying earthquakes and volcanoes?

I think to the extent that having a good understanding of physics, and more generally the equations that describe how things work, affects how you think about observations. And so what is the connection between fluid mechanics and earthquakes and volcanoes? Maybe not so much the details, but it’s a way of thinking about the world. When I look at a volcanic eruption or some data about earthquakes, I do think about the physics that governs what we’re studying. It’s a step beyond just trying to develop a conceptual understanding; along with that is the mathematical understanding.

Ultimately, what we’re trying to do is build models for how we think these Earth systems work. And underpinning all models is a set of equations. It’s probably why there are so many people in your business who take advantage of their physics backgrounds. They understand how things work and how to think about equations and mathematics to interpret patterns or observations. Probably half the people I went to graduate school with work in finance.

But it isn’t always easy to reduce market behavior to a formula because of the role that humans play in it.

Yeah. That’s right, but there are aspects of trying to understand things like volcanoes and earthquakes that are just as complicated because there are so many things interacting with each other. Solving from first principles a model that explains everything is just not possible, because they are too complicated or too complex. Even though we know there’s an underlying set of physical and chemical laws, or maybe even biological laws, that govern what we see, the complexity of those systems makes solving them in traditional ways intractable.

Has Big Data made it easier for you to predict things like earthquakes or when the next volcano will erupt?

I’m not sure. It would be nice to be able to say yes or no. We do not predict earthquakes yet; in fact, even in the business now, I think people will not use the word “predict.” We can forecast earthquakes in much the same way that we have a weather forecast that’s a probabilistic statement of what might happen. But I’m optimistic that with volcanoes we will make much more progress, because when a volcano erupts, there are more things that take place beforehand that tell us what’s happened. And the access to way more data because of low-cost sensors and satellites and nanosats will lead to a huge explosion in data, and we have the abilities now to do something with that data.

So I think the answer is not yet — in that we’re not predicting earthquakes. The eruption that’s going on in Hawaii [in June 2018], I don’t think we can tell you when it’s going to end. It would be nice to be able to, but I can see the point arriving where, at least for volcanoes, we’ll be able to say more than we currently can. And part of that will be enabled by Big Data. 

Is it easier to try to predict earthquakes or volcanoes?

I think volcanoes should be much easier because we know that before volcanoes erupt, all kinds of things start moving and happening underground that create different types of signals that we can measure. Earthquakes may start so quickly that there’s nothing that we can really measure leading up to them. But even with volcanoes, I think it will be a long time before we start using the word “predict” as opposed to “forecast.”

Maybe the distinction between a prediction and a forecast for everyone outside the business is too subtle. A prediction is either right or wrong. A forecast is a probabilistic statement: There’s a 10 percent chance something will happen, or there’s a 20 percent chance your property will be inundated by lava. I think that’s something we can say. And so the distinction may be subtle, but it affects how you think about natural hazards and how you respond to them.

How does this apply to the work you’ve done with Mars?

Probably not at all. I think many of us who study other planets do so because, first, they’re so fascinating. People’s intrinsic curiosity about what’s out there is enough on its own to drive that interest, but there’s another reason: If we think we understand how things work on Earth, we should be able to explain how things work on all these other planets. And the fact that there are so many mysteries out there is a good reminder of how little we truly understand how Earth systems work more generally.

On Mars, to me the biggest and most interesting question is understanding the history of liquid water. We look at Mars and we see so many signs that tell us liquid water was flowing over the surface. There may have been big oceans. There are big lakes. And we are not able to predict or explain how Mars could have been warm enough to allow liquid water to exist on the surface. So there remain some fundamental paradoxes about understanding a planet in our own solar system that is the most Earth-like of all of them, and they’re highlighting fundamental gaps in our understanding of how climate works, how fluids move through a planet.

In your recent paper in Nature, you concluded that volcanic activity may have played an important role in the formation of oceans on Mars. Where did you get the idea for your research?

Well, that’s an interesting question. I think we start with the question about which we care — and a question whose answer matters. So, on Mars, I think it comes back to liquid water on the surface and whether Mars, for example, had big oceans. Big oceans have a tremendous effect on the climate of a planet and its habitability.

I think we made a good case that Mars had big oceans. And then the question is, “Well, how can Mars sustain big oceans?” Volcanism may be one way of changing the climate of a planet, because volcanoes emit large amounts of gases into the atmosphere. To go back to a question you asked earlier about the connection between Earth and these other planets, on Earth volcanoes also have a huge impact on habitability. There’s what we call a supervolcano that creates supereruptions — Yellowstone being a good example. And if Yellowstone were to erupt like it did 600,000 years ago, I think all life as we know it on Earth would change profoundly. I’m not sure modern humanity would survive an eruption like that.

That’s a scary thought.

Yeah, I guess so. I mean, you can also be fatalistic and say, “Well, there’s nothing we can do about it. So if it happens, it’s going to happen.” On the other hand, I guess if we knew that we had 50 or 100 years to prepare, we probably could create the infrastructure needed to survive. We’re a pretty resilient species. If it were to happen tomorrow, not a chance, right? Airplanes wouldn’t fly, and we rely on them for transporting food from one place to another. And then, of course, we’d all have long-term health problems.

Won’t Elon Musk have built an entire colony on Mars by then?

Well, we’ll see. The cost of sending people to Mars and building colonies on Mars is going to be extremely high. Simply the amount of energy it takes to get things to Mars is very expensive, and then we need resources once we get there — energy supply, water, nutrition. It’s hard to imagine having a colony on Mars within the next decade because of the challenge of bringing the resources that we need to survive.

There is also a philosophical question. Should we be diverting so many resources to exploring and colonizing other bodies at the expense, obviously, of our own planet and people? We’re making sacrifices about keeping our own planet inhabitable. I have no strong opinions, but I do think that space exploration is an important part of who we are as a species. I remember when the satellite New Horizons launched to Pluto. I was teaching our introductory class for nonscientists about planets the day it launched. I showed a photograph of the launch and said, “I’m not sure why we’re spending money flying by a ball of ice in the outer solar system.” And it was anything but a ball of ice. We had great surprises. The pictures were beautiful. For the two dollars it cost each of us, it was a fantastic investment in sustaining the human spirit. So I hope we can continue as a society to keep exploring space, because of the things we learn. And, of course, it also creates job opportunities and other opportunities for people with technical skills and mathematical skills.

Do you plan to do more research on Mars?

Yeah, absolutely. I’ll probably work on Mars forever. This year in January, we submitted three different proposals to work on Mars. There’s a mission called InSight that launched in May, and it’s bringing geophysical equipment to the surface of Mars. It’s going to drill a hole to measure how much heat is coming out of the planet. I’m hoping that we can identify where liquid water and frozen water exist within the Martian subsurface from those measurements.

Do you have any interest in going to Mars?

I don’t think my family would be so happy to hear this, but I would go if I could.

And what would you hope to do there?

Fundamentally, I’m a geologist. I want to understand how planets work. I just came back from teaching what we call our summer field camp. We spend four weeks in the high California desert with students, making maps and trying to understand what we see. Every time I go out there and look at things that I’ve been studying for a long time and pick up and look at rocks, I come up with new ideas. I think it’s because the range of senses you get to deploy when you look at something and observe something, and the perspectives you get when you’re there in person, are irreplaceable. It’s not the same thing as reading a paper where someone describes something or looking at a photograph.

Every time I go out into the field and look at real rocks or make observations, I’m always struck by how we come up with new ideas and new hypotheses. That doesn’t happen when I just sit in my office here and solve equations. I’m sure the same thing will be true when we send people to Mars. We’ll be looking at Mars up close and interacting with that environment, and coming up with new ideas and new explanations.

I think even more exciting than Mars, though, are all these icy worlds out there that we now call ocean worlds — Jupiter’s moon Europa and Saturn’s moon Enceladus. They have liquid oceans in contact with rock. They’re erupting those oceans to the surface. If we’re interested in finding life elsewhere in our solar system, those are probably the best candidates. We’re sending an orbiter to Europa. Hopefully, we’ll send other satellites to land and visit Enceladus as well. But I think the scientific return from those moons will be greater than Mars.

What is most interesting about Europa?

Europa has a layer of ice at the surface, a 100-kilometer-thick ocean and then a rocky interior. And that rocky interior could be geologically active. We’re especially interested in the fate of that liquid ocean. Is some of that liquid ocean water coming up close to the surface of Europa? Because that ocean may be one of the few places in our solar system capable of sustaining life. And if that liquid water gets close to the surface, that would be life that we might be able to characterize or image or sample. 

I think that’s what makes these ocean worlds so exciting — that they are candidates for supporting life elsewhere in our solar system. It would be the chance to answer the question, first, “Is there life?” And then, “Is that life similar to life on Earth, or is it fundamentally different?” We don’t know that there’s life there at all, but if we’re looking for life elsewhere, Europa and Enceladus are great candidates.

 

Thought Leadership articles are prepared by and are the property of WorldQuant, LLC, and are being made available for informational and educational purposes only. This article is not intended to relate to any specific investment strategy or product, nor does this article constitute investment advice or convey an offer to sell, or the solicitation of an offer to buy, any securities or other financial products. In addition, the information contained in any article is not intended to provide, and should not be relied upon for, investment, accounting, legal or tax advice. WorldQuant makes no warranties or representations, express or implied, regarding the accuracy or adequacy of any information, and you accept all risks in relying on such information. The views expressed herein are solely those of WorldQuant as of the date of this article and are subject to change without notice. No assurances can be given that any aims, assumptions, expectations and/or goals described in this article will be realized or that the activities described in the article did or will continue at all or in the same manner as they were conducted during the period covered by this article. WorldQuant does not undertake to advise you of any changes in the views expressed herein. WorldQuant and its affiliates are involved in a wide range of securities trading and investment activities, and may have a significant financial interest in one or more securities or financial products discussed in the articles.