The researchers in this collaborative project seek to use GLAD800 (the Global Lake Drilling 800) system to retrieve sediment cores from Lake Peten-Itza in northern Guatemala to study climate variability in lowland Central America during the late Pleistocene and Holocene on time scales ranging from decades to millennia.
The researchers hypothesize that changes in the mean meridional position of the Atlantic inter-tropical convergence zone (ITCZ) are responsible for rainfall variations in the northern lowland Neotropics on interannual to multi-millennial time scales. The ITCZ is a region within 5 degrees of the equator where the trade winds converge to form low atmospheric pressure, enhancing precipitation and influencing global circulation. Coupled general circulation models indicate high sensitivity to climate and circulation changes in the high-latitude North Atlantic.
Specifically, the researchers will establish marine-terrestrial linkages by correlating rainfall and runoff proxies in sediment cores from Lake Peten-Itza with those from the Cariaco Basin, northern Venezuela, to determine regional precipitation changes. In turn, the Peten-Itza and Cariaco records will be compared with proxy signals from the high latitudes of the North Atlantic to assess linkages with that region. It is believed that terrestrial-marine-ice correlations of paleoclimate archives at sub-millennial time scales can be used to decipher the history of the northern Neotropic hydrologic cycle, its relation to the Atlantic ITCZ, and linkages to climate in the high-latitude North Atlantic. To accomplish this, six primary drilling sites have been identified in Lake Peten-Itza on the basis of detailed seismic surveys.
The Peten-Itza Scientific Drilling Project will have a strong education and outreach component through ongoing, close, and active collaboration with colleagues at Guatemalan universities (UVG and UNSC) in the research agenda. Both U.S. and Guatemalan undergraduate and graduate students will be directly and significantly involved in the research.
