Saturday, November 14, 2015

Modeling Tsunamis and Monitoring Earthquakes: an Interview with Geophysicist and MSS Speaker Diego Melgar

By Talya Klinger, MSS Intern

How can we meet the computational challenge of modeling and monitoring earthquakes in real time, and how can we anticipate and prepare for natural disasters? Diego Melgar, Ph.D. of the UC Berkeley Seismological Laboratory, is investigating these questions and more. As an assistant researcher, he develops earthquake models and tsunami warning systems using high-rate GPS data, paving the way for better earthquake preparation.

1. How did you first get interested in seismology?

I grew up in Mexico City, where earthquakes, volcanoes, hurricanes and other natural hazards are a fact of life. I've also always liked math and physics, and so, when it was time to go to college and select a program, I looked around and I found a geophysics degree at the National University that studied the Earth and its physics with lots of math. It seemed like a great idea to me!

2. What are some of the most challenging aspects of modeling natural disasters in real-time?

That they are complex and that measurements are sparse. Many things are going on during an earthquake or any other natural hazard, they're really complicated! Saying something about them very quickly with sparse observations and being right about it is a real challenge.

3. How do you go about making tsunami propagation models more efficient?

We run them in parallel on bigger computers. We can now make very detailed models of the tsunami in less than one minute.

4. How does the technique of real-time monitoring impact geological research and natural disaster preparation?

 Basic research allows us to find out what are the laws of physics and chemistry that make earthquakes and other hazards do what they do, it lets us find about what makes the Earth tick. In turn, the more we know about the physics and chemistry of the Earth the more intelligent we can make our warning systems, we can provide more relevant and precise information in shorter periods of time.

5. Tell us about your work in analyzing the magnitude 7.8 earthquake in Nepal: what did you discover about its source?

Nepal was a very interesting event because in spite of the fact that there were thousands of casualties and widespread destruction, it really could have been a lot worse. Given the state of development of the country we could have easily seen 150,000 casualties like we did in Haiti in 2010, but we did not. After some research we learned that part of the reason for this is that the earthquake rupture was very smooth and that smoothness lead to less shaking than we would have expected.

6. Finally, what advice do you have for students who are interested in seismology, geophysics, or signal processing?

Learn physics, learn math, and learn computers. Earth sciences are an incredibly rich field where these tools are really important. But also go outside, go hiking, look at rocks, notice how each one is different and wonder where they came from. The Earth is a beautiful laboratory and we should enjoy it with our minds but we should also go out and experience it.

To find out more, watch Dr. Melgar's Marin Science Seminar presentation on November 18th, 7:30-8:30 pm at Terra Linda High School, Room 207.

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