When were the Greenland and Antarctic ice sheets collapsed in the past?
I investigate the history of the Greenland and Antarctic ice sheets over the last 5 million years. In particular, I have focused on documenting when these ice sheets disappeared and under what climate conditions. These results can provide important empirical evidence for the future of these ice sheets and their impact on sea-level rise.
How have Arctic glaciers changed in the recent past?
My research on Arctic glaciers has taken me to Alaska, Greenland and Svalbard. Here, I am documenting the natural variability of ice margins in the geologically recent past of the Holocene and the Common Era. The goal is to determine if current behavior of glacier margins has moved beyond their natural variability, detecting emergent behavior in response to human-induced climate change.
How did Laurentide ice-sheet deglaciation affect climate, sea level and human migration?
The Laurentide ice sheet was the largest ice-age ice sheet, covering all of Canada and the northern U.S. I reconstruct the timing and rates of Laurentide retreat to relate its changes to past abrupt climate and sea-level rise events, like the Younger Dryas and meltwater pulses. Another important avenue of this research is documenting when different migration pathways to the Americas opened up for early human's migrating to the continent.