Hola! My name is Nicola and I’m a first year PhD student at the University of East Anglia studying the interplay of bacterial communities, trace gases, and soil formation on volcanic rock.
When volcanoes erupt, they create new land surfaces for bacteria to colonise. As time progresses, soil is formed, and plants are able to grow. My research studies the very start of this process; emerging soils in extreme environments and the bacteria that help shape them. To do this, I am researching the use of trace gases, such as carbon monoxide, methane, and hydrogen, by bacteria. These gases are ‘trace’ because they are at very low levels in our atmosphere but can be valuable carbon and energy sources in volcanic soils; any bacteria that can use these gases for food have an advantage in these extreme conditions!
To study this in action, I needed to go sampling. With my supervisor Marcela and external collaborator James, we made our way to southern Chile in January 2024 with the aim of sampling from three different volcanoes: Antuco, Calbuco, and Llaima. Over the next two weeks, we collected over 30 bags of soil and took over 150 gas samples for analysis back in the lab.
Our first stop was Antuco in Parque Nacional Laguna del Laja, where accompanied by condors we hiked two and a half hours over steep, loose tephra and sharp, unstable lava rocks to the lava field of the volcano to sample inside a lava tube. Lava tubes are tunnels left behind when the slow flowing outside lava cools quicker than the fast-flowing inner lava. The outside lava crusts over and the inside lava keeps flowing, leaving a space behind that forms a lava tube – this one was big enough to stand up in! The soil that forms in these areas, sheltered from sunlight, makes for interesting study into the bacterial communities that inhabit them and forms the backbone of my PhD!
The lava field of Antuco (2150m above sea level). Photo by Nicola Fantom.
(Geologist Daniel Basualto, me, and my supervisor Marcela Hernández in the lava tube at Antuco. Photo by Jorge Romero)
The second volcano we visited was Calbuco in Reserva Nacional Llanquihue, near the town of Ensenada and Lago Llanquihue in the south of Chile. Calbuco last erupted in 2015 and the effects are still shown in the landscape which is covered in loose rocky material from the volcano. We sampled material from historical eruptions up to 100 years ago to investigate changes in bacterial communities over time. Unlike Antuco, it rained torrentially at Calbuco for the three days we were there, but we still came away with all the samples we needed.
The area surrounding Calbuco is covered with rocky tephra. Photo by Nicola Fantom.
Our final volcano was Llaima in Parque Nacional Conguillío. Here, over two days, we sampled soil from lava flows from different historical eruptions to study bacterial communities and trace gas consumption. The national park itself is beautiful, having three lakes, Araucaria (monkey puzzle) trees, and also being a native habitat of the Andean puma cat. Climbing onto the lava flows required scrambling over sharp unstable rocks in very warm weather; at one point our probe measured over 40°C!
Lava flow on the South side of Llaima. Photo by Nicola Fantom.
Sampling aside, it wouldn’t have been a true fieldwork experience without trying some local food! Throughout the trip we were treated to a selection including an unbelievably good barbecue, pastel de choclo, completos, ceviche, and of course lots of seafood meant Chile’s sushi was incredible! This sampling trip wouldn’t have been possible without the help of so many people. We couldn’t have done it without the spectacular help of Chilean geologists Daniel and Jorge with everything from geological knowledge and logistics to a fantastic barbecue! Thanks also go to Barbara and Pablo for all their help and fantastic hospitality (and Chilean pisco sour!) at Calbuco, and finally to Pia for help with logistics!
