Quaternary & Paleoclimate Research

Department of Geology & Geophysics, UW-Madison

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Welcome to our home page. This page includes information about the Quaternary & Paleoclimate Research group in the Department of Geology & Geophysics at the University of Wisconsin-Madison. Our group studies a variety of areas dealing with Glacial Geology, Paleoclimatology, Glaciology, and Paleoceanography as well as more applied problems in Engineering Geology and Hydrogeology. Our research group is part of the much larger Quaternary & Paleoclimate Research community at the University of Wisconsin (Campus Quaternary Link). In addition, the University of Wisconsin hosts the Center for Climate Research which focuses on past, present and future climate change.

Understanding the causes and impacts of past climate changes is critical to predicting the present and future response of the climate system to global warming. Quaternary Research and Paleoclimatology are thus burgeoning fields in Geology and the scientific community as a whole. The Quaternary Period includes the last 1.8 million years. One of the most significant aspects of this period is the expansion of Northern Hemisphere ice sheets collectively known as the "Ice Age". Evidence from the deep oceans indicates that there have been numerous cold (glacials) and warm (interglacial) periods during the last 2.4 million years (see figure below).

This figure shows the variation in benthic foraminifera oxygen isotopes for the last 4 million years where lighter values indicate interglacial periods and heavier values indicate glacial periods. Ratios of ¹⁸O relative to ¹⁶O increase with the growth of ice on continents and decrease with the melting of ice; thus serving as a proxy of continental ice volume.

The most recent glaciation began about 125,000 years ago and climaxed about 21,000 years ago. At this time, over 30 percent of earth's surface was covered by ice, and sea level was at least 125 meters lower than present (see below figure). During the last deglaciation, temperature, sea level and climate fluctuated rapidly on millennial time scales possibly due to variability in Atlantic meridional overturning circulation and changes in the hydrologic budget of the North Atlantic. These past rapid changes provide a useful natural experiment from which we can deduce the sensitivity of the climate system and better predict its future response to global warming.

This figure shows multiple proxies and measurements of (from top to bottom) Atlantic meridional overturning circulation (up is greater overturning), Greenland temperature as recorded oxygen isotopes from the GISP2 ice core (up is warmer), atmospheric carbon dioxide concentration from Antarctic ice cores, relative sea level from far field sites, and June solar insolation (the driving force behind the glacial-interglacial cycle). The gray bars denote periods of abrupt sea level rise in less than 500 yrs (light gray bars) and cold events (dark gray bars, H1=Heinrich Event 1, YD=Younger Dryas, 8.2 ka CE=8.2 kyr BP cold event).