Introduction for Todd Gleeson at the ADVANCE Seminar

Dean Gleeson earned a doctorate from the University of California, Irvine in developmental and cell biology in 1979, and has been a member of the Boulder faculty since 1981. He is a professor in the Department of Integrative Physiology, and maintains a research laboratory that has trained numerous undergraduates and 20 graduate students and postdoctoral associates. He earned Boulder campus Student Office of Alumni Relations (SOAR) teaching-honors in 1985. He has published over 100 articles and abstracts on his studies of muscle carbohydrate metabolism and the metabolic consequences of muscle fatigue in animals, and he is an elected fellow of the AAAS. He served as Associate Vice Chancellor for Faculty Affairs on the Boulder campus from 1997-2001, and has served as dean of the College since 2001.

Millennial-Scale Climate Variability during the Last Glacial Period in the Tropical Andes

Millennial-scale climate variation during the Last Glacial period is evident in many locations worldwide, but it is unclear if such variation occurred in the interior of tropical South America, and, if so, how the low-latitude variation was related to its high-latitude counterpart. A high-resolution record, derived from the deep drilling of sediments on the floor of Lake Titicaca in the southern tropical Andes, is presented that shows clear evidence of millennial-scale climate variation between ~60 and 20 ka BP. This variation is manifested by alternations of two interbedded sedimentary units. The two units have distinctive sedimentary, geochemical, and paleobiotic properties that are controlled by the relative abundance of terrigenous or nearshore components versus pelagic components. The sediments of more terrigenous or nearshore nature likely were deposited during regionally wetter climates when river transport of water and sediment was higher, whereas the sediments of more pelagic character were deposited during somewhat drier climates regionally. The majority of the wet periods inferred from the Lake Titicaca sediment record are correlated with the cold events in the Greenland ice cores and North Atlantic sediment cores, indicating that increased intensity of the South American summer monsoon was part of near-global scale climate excursions.