It might seem strange that Sam Zipper spent his summer on balmy Cape Cod studying the western Canadian Arctic. But for Zipper, examining sediment cores from the Mackenzie River Delta with Woods Hole Oceanographic Institution (WHOI) geologist Liviu Giosan was a great way to connect his interests in geology and environmental analysis. He studied both at Pomona College, where he graduated last spring.
In the Coastal Systems lab at WHOI, Zipper analyzed the cores to construct a record of how sediments within the watershed changed over the past 1,000 years and examined how the permafrost responds to climate change.
The river delta contains thousands of small lakes, which annually flood with sediment-laden water during the spring snowmelt. This provides distinctive layers of sediment, which are ideal for assessing yearly fluctuations of carbon levels, sediment particle sizes, and other geological and geochemical clues. Those clues will reveal how the composition of the permafrost changed during and after ancient periods when Earth’s climate oscillated naturally into what are known as the Medieval Warm Period and the Little Ice Age.
“This will hopefully let us know how much carbon we can expect to enter the atmosphere in the future due to permafrost degradation,” Zipper said. Melting permafrost is one of many results of warming climate in the Arctic and also leads to ecosystem changes and land subsidence. “This is a kind of pioneer study, and will give us some background about the hydrology of the Arctic.”
Zipper said he plans to pursue some kind of career in the earth sciences. “I’m interested in the interactions of earth, water, and people, but I’m not really sure where on the spectrum.”
Before returning home to Edmonds, Wash., Zipper planned to hike the White Mountains section of the Appalachian Trail. He will return to the Coastal Systems Group in the winter to work as a research assistant.
Sam Zipper studied sediment cores from the Mackenzie River Delta to explore how climate change may affect Arctic permafrost. (Photo by Tom Kleindinst, Woods Hole Oceanographic Institution)