Richard B. Alley
The Pennsylvania State University
Election Year: 2008
Primary Section: 16, Geophysics
Secondary Section: 15, Geology
Membership Type: Member
As a glaciologist, I have helped understand the climate records in ice cores, the potential for ice-sheet flow changes to affect sea level, and the influence of glaciation on landscapes. Through study of ice-core physical properties and processes, I contributed to improved annual-layer dating of the ice cores. We combined the accurate ages with flow modeling to estimate accumulation-rate histories, and used these to correct chemical records for changing dilution, and to combine borehole temperatures and isotopic data for paleothermometry. The improved confidence in ice-core paleoclimatology helped demonstrate the reality of large, widespread, abrupt climate changes, which were subsequently defined and interpreted by the National Research Council committee I chaired. Concerning ice flow, our interpretation and modeling of geophysical data identified water-saturated till as the most effective lubricant for ice streams. Our recent and ongoing work on ice-shelf buttressing of ice streams, sedimentary stabilization of grounding lines, iceberg calving, meltwater penetration of ice sheets, and related topics contributes to the understanding needed to predict ice-sheet changes, while our studies of supercooling of subglacial waters identified a key stabilizing feedback for glacier-valley profiles affecting mountain-belt evolution. In addition, I have aided policymakers and the public in assessing and publicizing these results.