1. S. R. O'Brien, M. S. Twickler, S. I. Whitlow, Glacier Research Group, Institute for the Study of Earth, Oceans, and Space, University of New Hampshire, Durham, NH 03824, USA.
2. P. A. Mayewkski, Glacier Research Group, Institute for the Study of Earth, Oceans, and Space, and Department of Earth Sciences, University of New Hampshire, Durham, NH 03824, USA.
3. L. D. Meeker, Glacier Research Group, Institute for the Study of Earth, Oceans, and Space, and Department of Mathematics, University of New Hampshire, Durham, NH 03824, USA.
4. D. A. Meese, Cold Regions Research and Engineering Laboratory, Hanover, NH 03755, USA.