The Quaternary Period is typified by repeated oscillations in the global climate system between glacial and interglacial states. The characteristics of the transitions manifested during each cycle in the Northern and Southern Hemispheres, although broadly synchronous over longer time intervals, nonetheless differ at millennial to sub-millennial time-scales. This is seen, for example, in the asynchronous trend between hemispheres in temperatures changes derived from ice-cores in both Greenland and Antarctica, and is also expressed in the bi-polar seesaw behavior observed in the timing of the Younger Dryas (11.5-12.9 ka) and the Antarctic Cold Reversal (12.9-14.5 ka) deglacial cooling events in the Northern and Southern Hemispheres, respectively. Establishing the exact timing and location of climate shifts associated with changes in the components of the climate system can tell us the relative influence of various forcing and propagation mechanisms in the global climate system (e.g., the strength and response of North Atlantic Deep Water formation in the oceanic circulation system, or the role of atmospheric CO₂), along with how they may have operated in each hemisphere during the end of the last glacial period and during deglacial times (ca. 11-16 ka). This project aims to reconstruct the glacial history of a key latitude in the Southern mid-latitudes in order to infer possible climate conditions at certain points in time since the Last Glacial Maximum. We will use surface exposure ages from terminal moraine boulders deposited by mountain glaciers and Patagonian outlet glaciers to reconstruct periods of deglacial warming/drying in the Southern mid-latitudes of Patagonian Argentina (50-51˚S). In the context of an existing regional dataset of moraine ages along a latitudinal transect from Tierra del Fuego to the equator, our knowledge of the Southern Hemisphere's response and role in the global climate since the last ice-age can be improved.

• Anders Carlson
• Brad Singer

GRADUATE STUDENT

• Dan Murray

Ackert et al., 2008, Science

Douglass et al., 2005, Geology

Douglass et al., 2006, Quat. Geochron.

Kaplan et al., 2005, Quat. Res.

Kaplan et al., 2004, GSA Bulletin