Understanding the MIS 5e in Central America: the Chalco Lake perspective
Abstract
Southestern Mexico is a biogeographic divide between the Neotropics and temperate region. Prior work has established that Dansgaard-Oeschger and Heinrich events influenced Central America as well as North America, but there is a knowledge gap relating to rapid climate change associated with the termination and initiation of glacial episodes in the American tropics. Here we present pollen, charcoal and stratigraphic data derived from the lower part of a 122-m long composite sedimentary sequence from paleolake Chalco in Southeastern Mexico D.F. (19°14'40.99''N/98°53'30.99'', 2245 m.a.s.l.). This study established the paleoclimatic and vegetational dynamics of the northern Neotropics during MIS 6-4 using fossil pollen, charcoal and stratigraphic analysis. The history of Chalco Lake has been strongly influenced by volcanic activity around the basin, for example, four pumitic events and eight ash layers were found in the 20 m of core discussed here. Pollen data derived from the sediments showed abrupt changes in the vegetation assemblages throughout the period of study. Quercus, Pinus, Abies and Picea were dominant types at different times in the lake history reflecting changes in both temperature and precipitation. Our data indicate that at the peak of MIS5e Lake Chalco dried out, suggesting warm and dry conditions. Charcoal analysis indicated that except during the period when the lake dried out, natural fire was a component of this landscape. This study demonstrates that understanding MIS 5e, which was the last warm period before the present, is important to contextualize modern climate change and refine regional vegetation models.
- Publication:
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AGU Spring Meeting Abstracts
- Pub Date:
- May 2013
- Bibcode:
- 2013AGUSMGC54A..03C
- Keywords:
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- 1605 GLOBAL CHANGE / Abrupt/rapid climate change;
- 1637 GLOBAL CHANGE / Regional climate change;
- 1616 GLOBAL CHANGE / Climate variability