Alley, Richard B. (earth scientist)


(1957- ) American Glaciologist, Climate Modeler (Climate Change)

Because the polar ice caps are located in an area where temperatures are constantly below freezing, all precipitation that occurs on them must be frozen. Therefore, it is preserved for as long as the ice sheets remain. Because there is precipitation every year, and the precipitation traps a little bit of the atmospheric gas that it passes through, ice sheets contain a continuously preserved record of the Earth’s atmosphere for up to hundreds of thousands of years. Richard Alley analyzes deep cores taken from the continental ice sheets in Greenland and Antarctica, conducting physical studies to complement isotopic, chemical, and other measurements made by collaborators. The combined data provide detailed information on climatic conditions in the past. He showed that accumulation rates for ice sheets are extremely variable depending upon whether the conditions were glacial or interglacial (between ice ages). Surprisingly, almost half of the glacial-interglacial change was achieved in a few years. This discovery means that climate changes are not slow as was previously envisioned by Earth scientists but instead can be alarmingly rapid. Some of these abrupt climate changes are linked to great surges of the ice sheets in the great ice ages. They left evidence in sedimentary deposits around the North Atlantic. Alley’s findings about the mechanisms that caused these surges have led him to the idea that surges of the West Antarctica ice sheet are possible in the future. This research is summarized in the 2002 book The Two-Mile Time Machine: Ice Cores, Abrupt Climate Change and Our Future.

Richard B. Alley, in full field gear, standing in front of a ski-equipped LC-130 Hercules aircraft of the 109th U.S. Air National Guard in Sondrestrom, Greenland

Richard B. Alley, in full field gear, standing in front of a ski-equipped LC-130 Hercules aircraft of the 109th U.S. Air National Guard in Sondrestrom, Greenland

In studying the movement of glaciers, Alley found that subglacial sediments with meltwater serve to lubricate the basal contact of the glacier with the ground, allowing it to attain relatively high velocity. This research transformed Alley into one of the foremost authorities on continental glacier mechanics and processes. He also became one of the leading proponents of the view that the radical and abrupt climate changes that occurred during transitions to and from ice ages might have implications for future climate changes. He discovered further supporting evidence for this stand using a newly devised ice-isotopic thermometer. By analyzing the stable isotopes in the ice he could determine paleotemperatures. He calibrated this thermometer using modern ice. The result of his analysis of ice cores is that there were average surface temperature changes of some 20°C (36°F) between ice ages and interglacial periods. It was not expected that these variations would be so drastic. By compiling all of these results of the ice core research with sedimentary and deformational data, Alley formed a new dynamic model for the advance and retreat of continental glaciers. They can no longer be considered as slow-moving static bodies with little to no variation but rather very active bodies with diverse processes and modes of operation.

Richard Alley was born on August 18, 1957, in Ohio. He attended Ohio State University in Columbus, and earned a bachelor of science degree in geology and mineralogy in 1980, summa cum laude and with honors and a master of science degree in geology in 1983. He earned a Ph.D. in geology with a minor in material sciences from the University of Wisconsin at Madison in 1987. He remained at University of Wisconsin for one year as an assistant scientist before joining the faculty at Pennsylvania State University at University Park, where he remains today. Alley was named the Evan Pugh professor of geo-sciences beginning in 2000. Alley is married and the father of two children.

Richard Alley is leading an extremely productive career. He is an author of more than 120 articles in international journals and professional books and volumes. Many of these papers are benchmark studies of ice mechanics and climate modeling and many appear in the prestigious journals Nature and Science. They have been cited an astounding 3,500 times to date. He is also an author or editor of four books. His research and teaching contributions have been well recognized by the profession in terms of honors and awards. He is the recipient of the Horton Award from the American Geophysical Union, the D. L. Packard Fellowship, and the Presidential Young Investigator Award. From Pennsylvania State University, he won the Wilson Teaching Award and the Faculty Scholar Medal. He was also invited to give testimony to then-U.S. vice president Al Gore.

Alley has also performed significant service to the profession. He serves or has served on panels and committees for the American Geophysical Union, the National Science Foundation including the Augustine Panel, the International Glacio-logical Society, the Polar Research Board, and the National Research Council, among others. His work has also attracted the attention of the popular media. The British Broadcasting Corporation and National Public Radio have featured him in special programs.

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