Expedition makes subsurface maps, takes samples in Chilean peatlands

(Image: College of Geosciences)

With funding from the National Geographic Society, a Texas A&M University researcher from the College of Geosciences led an expedition this summer to sample peatlands in Chile and determine carbon stocks using peat cores and ground-penetrating radar.

Julie Loisel, an assistant professor in the Department of Geography and a National Geographic Explorer, led a group of five A&M undergraduates, along with a geophysicist from the University of Wyoming, Andrew Parsekian, to Tierra del Fuego in southern Patagonia, Chile.

The process of sampling each peatland location included coring, subsurface GPR mapping and collecting surface vegetation samples. The team also set up a weather station and water-level data loggers in monitoring wells.

Peatlands are unique environments that hold deep layers of important environmental data. They are also “the most effective sink of carbon on the planet,” Loisel said. Peatlands store large quantities of carbon within their thick soil layers over thousands of years, which causes them to act as a cooling climate agent on a global scale, she said.

They also contain decomposed plant fragments, volcanic ash and many other relicts from the past that can date back thousands of years. She explained that peat deposits can be cored and their layers read like a history book.

Peat cores are a sort of natural time capsule, and their content reveals important information about the local and regional environment.

The first collection site was called Rasmussen Peatland. Located at higher elevation towards the Cordillera Darwin, this peatland was harsh with freezing air temperatures and strong winds. The peatland surface was frozen and covered with iced-over puddles.

“Obtaining core samples there provided good training for new members, interesting vegetation and beautiful views,” Loisel said.

Next the crew traveled to Flarks Peatland. This area was different from the previous one; in a milder valley, its vegetation was more lush and displayed bright colors of reds, oranges, and yellows. This peatland had also been cut down by the eroding action of a river, which allowed the team to observe the peat layers directly. Over the next four days, the team traveled to four more sites.

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