L. G. Thompson, M. E. Davis, K. A. Henderson, and J. F. Bolzan are at the Byrd Polar Research Center and Department of Geological Sciences, Ohio State University, Columbus, OH 43210, USA. T. Yao is at the Lanzhou Institute of Glaciology and Geocryology, Lanzhou, China. E. Mosley-Thompson is at the Byrd Polar Research Center and Department of Geography, Ohio State University, Columbus, OH 43210, USA. P.-N. Lin and J. Cole-Dai are at the Byrd Polar Research Center, Ohio State University, Columbus, OH...