Ice Core Research Is History Lesson

Kaitlin Keegan studies firn, the top 100 meters of an ice sheet that contains snow layers that are compacting are undergoing the process of becoming glacial ice. 

Engineering Sciences

Kaitlin Keegan, PhD, studies firn, the top 100 meters of an ice sheet that contains snow layers that are compacting are undergoing the process of becoming glacial ice. Firn is where climate information gets recorded into the ice sheet. If we understand how climate information gets recorded then we can understand how climate has changed naturally in the past.

In 2009, Kaitlin and colleagues drilled an 80-meter deep core of firn layers at NEEM camp, in Northern Greenland. The core was shipped to a lab in the U.S. where they’ve studied the various layers and their properties. One significant finding was a layer in the firn that formed in 1889 and indicated a widespread melt event over the entire surface of the Greenland Ice Sheet.

In 2012, after a visit to Summit Station on the Greenland Ice Sheet, Kaitlin discovered that most of the surface of the ice sheet melted in 2012 as well. Kaitlin’s results show that these melting events are caused by warm summers where large wildfires take place in North America and Siberia. The wildfires produce ash that reaches the ice sheet, darkens the surface, increases sunlight absorption, and speeds up melting.

Kaitlin’s research highlights the importance of the Greenland Ice Sheet to the global climate and helps to predict how future changes will affect the rest of the world. Dr. Keegan recently moved to Denmark to begin a postdoctoral position at the Center for Ice and Climate at the University of Copenhagen where she continues her work on Greenland Ice Sheet dynamics. Her research has been written about in Smithsonian Magazine, The New York Times, and the Proceedings of the National Academy of Sciences, among others. And read about her in the Graduate Forum.

YouTube: Kaitlin Keegan on how firn records climate information

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