PALEOLIMNOLOGICAL STUDY OF DIATOMS IN LAKES ALONG THE CENTRAL AMERICAN VOLCANIC ARC

Lake sediment records provide short- and long-term indications of climate change, lake chemistry, ecology, and anthropogenic modifications. To investigate several of these changes in the Guatemalan highlands, we collected sediment cores from lakes Atitlán and Ayarza using a gravity corer (investigated core length for Lake Atitlán is 84 cm and from Lake Ayarza is 113 cm). These cores are vital to understanding how different local, regional, and global changes can affect lake systems. For these cores, we intend to reconstruct past climate and changes in lake chemistry using fossil diatom assemblages. Lakes Atitlán and Ayarza are deep caldera lakes that formed by volcanic eruptions along the Central American Volcanic Arc. The origins for Lake Atitlán extend back to ~80 ka and, for Lake Ayarza, back to around 23 ka. The meter-long sediment cores investigated in this study are estimated to be about 1000 years old, based on sedimentation rates of nearby lakes. The data from these cores will provide evidence of how these lakes have evolved during the last millennia and how they have responded to global climate change, anthropogenic modification, and other local and regional events. This study will give us insight into how similar events may impact other lakes in this region.