Biologist Alejandra Rodriguez Abaunza, a Ph.D. student in earth and environmental sciences in the School of Science at Indiana University Indianapolis, has focused on reconstructing past climate conditions in Lake Tota, the largest lake in her home country of Colombia. She researches changes in precipitation patterns over the past 20,000 years, using lake sediments and a variety of proxies to understand the complexity of the tropical climate and refine future projections.
Few climate records are available from the tropics, with institutions focusing on more developed areas, so her work is essential as a benchmark for improving climate models and projections for the future. A surprising finding during a field expedition two years ago led her to explore different angles that have broadened her research.
During that expedition, she and her team recovered 500 kilograms of sediment cores. These tubes of mud - extracted from the bottom of a lake, river or ocean - record changes in the surrounding environment through the particles that settle on the bottom. The information gained from these cores helps provide a baseline record of how the Earth's climate varied before modern human society.
But within those cores, they found something unexpected: volcanic ash. The inorganic material, which by definition doesn't have the living compounds she studies, posed a challenge for Rodriguez Abaunza.
"We studied the past climate, but not the impact of the volcanism in the Andean lakes," she 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."
This discovery led her to seek out a course in volcanology; that's when she came across the International Enhancement Grant. This funding opportunity helps IU graduate students pursue international academic experiences that enhance their research in ways not possible on their home campus.
With this support, Rodriguez Abaunza attended the eighth International Volcanology Workshop in Manizales, Colombia, where she spent a week in the northern volcanic front of the Andes, an area at the same latitude as Lake Tota but within a different mountain range. The program offered an immersive experience, beginning with two days of lectures at the University of Caldas, where she learned about the structures and properties of volcanic deposits.
Her goal was straightforward: to learn the basics of volcanology and understand how volcanic deposits could be distinguished from lake sediments. This knowledge, while not directly part of her Ph.D. research, will play an important role in future projects that seek to understand how volcanic activity has shaped climate records in the region.
The remainder of the program was spent in the field, where participants visited at least 10 volcanic deposits, collecting and analyzing samples. Working alongside four professors - specialists from Colombia, Argentina, Spain and Italy - she gained hands-on experience that deepened her understanding of volcanology, developing skills to interpret geologic histories observing volcanic rocks.
While the course itself lasted a week, the grant also allowed her to spend an additional week in the volcanology lab at the University of Caldas, analyzing the samples collected during the program. This additional analysis helped her explore potential connections between volcanic deposits and the lake's sediment records.
"It's not my main question in my thesis," she said. "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."
Fieldwork always comes with challenges like unpredictable weather, but in this case, she found that the logistics of the course were well-organized. Academically, the biggest challenge was diving into an entirely new field.
"For me, it's not just understanding how volcanoes work but also how they can impact my country and my research area," she said.
Preparing for the grant application was another important step in the process.
"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."
Looking ahead, her research goals remain focused on the study of tropical lakes and their role in 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."
