1 Department of Geography, University of Wisconsin-Madison, Madison, WI 53706; semunoz@wisc.edu.
2 Department of Geography, University of Wisconsin-Madison, Madison, WI 53706;
3 Department of Earth and Planetary Sciences, Washington University in St. Louis, Saint Louis, MO 63130;
4 Department of Anthropology, University of Wisconsin-Madison, Madison, WI 53706;
5 Department of Geography, University of Wisconsin-Madison, Madison, WI 53706; Center for Climatic Research, University of Wisconsin-Madison, Madison, WI 53706.