Global Warming Before Our Time: Ph.D. Student Andres Hernandez Nava Shares the Story of a Breakthrough Discovery

Andres Hernandez Nava

By Lida Tunesi

Ph.D. candidate Andres Hernandez Nava was an undergraduate student at the University of California, Berkeley, when he met Professor Benjamin Black, then a postdoc at the same school. Nava had read and admired Black’s research, and asked if they could do research together.

Fast forward to the present: Nava is now a fifth-year Earth and Environmental Sciences student in Black’s lab and was recently first author on a paper published in the Proceedings of the National Academy of Sciences.

The study took a close look at a climate change event that happened several hundred thousand years before the end-Cretaceous extinction, the event that wiped out the dinosaurs. Nava and the other researchers wanted to figure out if carbon dioxide outgassing from the Deccan Traps, a region in west-central India formed by volcanic eruptions, could have been responsible for this warming event. By analyzing samples from the area, they found that carbon outgassing from lava volumes wouldn't have been enough to cause the climate shift, but when combined with outgassing from magmas that froze beneath the surface it could have been sufficient. The study could help scientists better understand the role of magmatism in environmental change.

India’s Deccan Traps, an ancient lava field covering about one-fourth of India, has been tied to the End-Cretaceous mass extinction some 66 million years ago. New research is helping to determine whether it played a significant role. (Photo credit: Loÿc Vanderkluysen, Drexel University)

Though Nava didn’t travel to the Deccan Traps himself, he has made trips to Virginia Tech to collect carbon dioxide data and to Caltech to get data on other gases. These numbers will inform the follow-up study on how substances like water, fluorine, chlorine, and sulfur drove melting to create the Deccan Traps.

Nava was already interested in this field when he was an undergraduate. At Berkeley he studied the length of time lava was exposed to the sun to deduce the time between lava flows. When he learned Black was headed to CUNY, Nava did some research on the university to see if it could also be a good fit for him.

“I learned CUNY was very diverse and represented the different populations and backgrounds of New York City,” Nava said. “That was very exciting to me because looking back, I felt like I stood out in the sciences. There weren’t a lot of people who looked like me. It was very exciting to go to a school where I didn’t stand out.”

After several years in his program, Nava can now offer advice to incoming graduate students. For one thing, he said, being successful also requires taking time outside the lab.

“Grad students are conditioned to work long hours,” Nava said. “but you need to take care of yourself. Go on walks, and get plenty of sleep. It’s the best way to keep your mind fresh.”

Students should also keep in mind that research is a long journey, he advised. Journal papers take many revisions, and research is not as cut and dried a process as some might think.

“The question you started with might change after you get your initial data or have discussions,” Nava said. “Be on the lookout for questions that might change how you view the work. Finding the best way to communicate your results so they make sense to people is a creative endeavor; it’s a work of art.”

Submitted on: APR 7, 2021

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