Geosciences Graduate Student to Study Extreme Floods in Norway

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Geosciences Ph.D. student Karin Lehnigk has been selected for a GROW-Norway award that will send her to the University of Bergen from January to August 2020 to conduct mapping and modeling work. This will help to determine the sequence of events that led to the formation of Hellemobotn Canyon at the head of a fjord, a narrow, deep inlet of the sea between high cliffs.

Lehnigk says that Hellemobotn Canyon is well suited to study because its features are well preserved; it has not been much affected by other types of weathering. “It’s small enough that we can constrain some things that we aren’t able to in bigger systems, like the path that floods took and how much source water there was.” Lehnigk adds, “Perhaps most importantly, all of the bedrock is granite, which is a rock type that’s compatible with a really robust method of cosmogenic nuclide exposure dating.” Lehnigk explains that this allows her research team to sample virtually any spot in or around the canyon and receive high-resolution information regarding when a certain spot was last impacted by floods.

“I’m interested in the relationship between high discharge floods and topographic processes,” Lehnigk says, “I’ll be looking for erosional impacts that extreme floods have on changing the landscape surfaces. I’m interested in seeing this in Norway because it happens there today in processes that are called glacier outburst flooding. That’s when ice that’s holding back a body of water suddenly breaks up, resulting in a lake that needs somewhere to go. The most impressive and well-studied examples of this happened in the past, but this process still happens today on a smaller scale in Norway.”

The Graduate Research Opportunities Worldwide (GROW), award expands opportunities for U.S. graduate students who are active awardees of the National Science Foundation’s (NSF) Graduate Research Fellowship Program, allowing them to engage in international research collaboration. As an NSF Fellow, Lehnigk applied for the GROW award last winter and was selected in July.

Lehnigk will spend part of the summer doing fieldwork in HellemobotnCanyon in northern Norway, but will primarily be based at the University of Bergen. There she will she will reconstruct the pre-canyon surface using geologic and geographic features left behind by the flood that formed them. This allows her to model floods over the reconstructed surface to see what areas would have been inundated by the earliest floods.

Lehnigk and her Norwegian research team will also collect samples for cosmogenic nucleic exposure dating. By identifying when a piece of rock was transported or deposited somewhere, Lehnigk and her team can start to put together a picture of what happened in the past to shape the land today.

“Scientifically, I really would like to know what processes are responsible for carving canyons in this manner. Our modeling will be able to be applied to places all over the world. When you have modern topography, there’s a whole history behind what you see today in the landscape that can be a lot more than what meets the eye,” says Lehnigk. “Personally, I’m really excited to work with international researchers and try out a new way of thinking about these problems in a new setting and mix it up a little bit. It’s always helpful to hear new perspectives.”

Lehnigk noted that depending on the university, the study of topography can fall into either the geology or geography department, as it sits between the two fields. At UMass, Lehnigk studies topography through the geology department, but at the University of Bergen, she’ll be working with the geography department, so she’ll have the unique experience of exploring her subject through another discipline and another country’s perspective.

Reflecting on the honor, Lehnigk is thankful for her lab mates as well as her advisor, professor Isaac Larsen, who encouraged her to apply for the GRFP. Larsen recently received a Fulbright Fellowship to conduct research in Austria during the same timeline that Lehnigk will be in Norway. She says she had not known that the NSF’s graduate research opportunity was available until Larsen suggested that she apply. “He’s been really helpful for me throughout the whole research process,” says Lehnigk. “I’m in his first cohort of graduate students. When I came in, it was just me and one other Ph.D. student and that was it. Since then, it’s grown to six students and postdocs, but it still feels like a really tight-knit group. There’s a sense of teamwork and it’s in all of our best interests to support each other.”