Indianapolis, Indiana – When Alejandra Rodriguez Abaunza set out to study ancient climate patterns hidden beneath the waters of Lake Tota in Colombia, she never imagined that her research journey would lead her deep into the fiery world of volcanoes. A doctoral student in earth and environmental sciences at Indiana University Indianapolis, Rodriguez Abaunza has devoted her academic path to understanding how the climate in tropical regions has shifted over thousands of years. But a surprise finding during a recent expedition sent her in an unexpected direction—one filled with ash, lava, and a completely new scientific language.
Rodriguez Abaunza’s work focuses on reconstructing past climates using lake sediments—essentially tubes of mud extracted from the bottom of a lake. These sediments act like time capsules, recording environmental changes through the layers of organic and inorganic material that settle over time. With few climate records available from the tropics, her findings serve as critical data points that help improve climate models and refine future projections.
Her main study site, Lake Tota—the largest lake in Colombia—is an important resource for the region and a vital source of information for her research. By analyzing sediment cores from the lake, she aims to understand how precipitation patterns have changed over the past 20,000 years. These shifts tell a broader story about how the Earth’s climate system has evolved, especially in tropical areas often overlooked by global research efforts.
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Two years ago, she and her research team extracted over 500 kilograms of lake sediment in a field expedition. They were expecting to find clues about rainfall, vegetation, and other climate indicators. But buried in the layers of mud was something entirely unexpected—volcanic ash.
“We studied the past climate, but not the impact of the volcanism in the Andean lakes,” Rodriguez Abaunza said. “It was a very interesting question not related to my research because in my country, there are a lot of volcanoes but very far from the lake.”
The presence of volcanic ash puzzled her. It was inorganic—outside her usual focus on biological markers—and it opened a new set of questions. How did it get there? What did it mean? And how could she differentiate it from other particles in the sediment?
Driven by curiosity, Rodriguez Abaunza decided to dig deeper, even though volcanology wasn’t part of her original research plan. She applied for and received an International Enhancement Grant from Indiana University, a program that supports graduate students seeking academic experiences abroad to enrich their studies.
With the grant, she traveled back to Colombia to attend the eighth International Volcanology Workshop in Manizales, a city located near the volcanic front of the Andes. There, she joined an immersive program that began with two days of lectures at the University of Caldas, where she learned how volcanic materials behave and how they differ from other types of sediment.
Her main goal was to understand how to recognize and interpret volcanic deposits in sediment cores like the ones she found in Lake Tota. While this wasn’t the primary focus of her Ph.D., the knowledge she gained could provide valuable context for future research.
The second half of the workshop took place in the field, where Rodriguez Abaunza and other participants visited a series of volcanic sites. They analyzed deposits, collected samples, and worked closely with experts from Colombia, Argentina, Spain, and Italy.
“It’s not my main question in my thesis,” she explained. “But it laid the foundation for future research. It created networking opportunities with volcanologists who can help us understand the impact and provenance of the volcanic deposits in lakes.”
She spent an additional week in the volcanology lab at the University of Caldas, analyzing the samples collected during the fieldwork. The hands-on lab experience gave her new tools and perspectives, as well as a greater appreciation for the complexities of volcanoes and their influence on the natural environment.
“For me, it’s not just understanding how volcanoes work but also how they can impact my country and my research area,” she said.
The experience also gave her a new set of skills—both academic and personal. Stepping into a completely different scientific discipline was a challenge, especially in a short amount of time. But Rodriguez Abaunza embraced it, eager to expand her horizons.
The process of preparing for the grant itself was also a learning experience. She emphasized the importance of having strong support from academic mentors.
“It’s very important to have your advisor’s support,” she said. “Not just because they must write a recommendation, but because they can give you comments and help you refine your application. The language you use in a grant application like this is different from academic writing in research papers.”
Even though volcanology was never part of her original plan, the experience helped her see how interconnected Earth systems really are—and how different scientific disciplines often overlap. Understanding how volcanic activity has impacted sediment layers gives her deeper insight into the records she studies, and helps paint a fuller picture of the forces shaping the planet’s climate.
Looking ahead, Rodriguez Abaunza remains committed to the study of tropical lakes and their role in understanding the global climate system.
“Everything in the climate system is connected,” she said. “The things that happen in the tropics affect the climate worldwide. My goal is to continue making connections, building networks and working in the tropical regions to understand how the climate has changed in the past, because that knowledge will help us predict what’s coming next.”
Her journey from lake mud to volcanic ash illustrates how science often unfolds in unexpected ways. And in her case, it’s not just about finding answers—it’s about asking the right questions, even when they come from a place you didn’t expect.
