The Holocene record of the Lake Izabal Basin – Peeking into one of the longest continental records of the northern Neotropics

Jonathan Obrist Farner, Assistant Professor, Missouri University of Science & Technology

The last 40 years have been marked by a significant decrease in Central American precipitation, with pronounced droughts affecting the lives of two million people. This decrease in precipitation has focused scientific attention on understanding potential precipitation trends during continued global warming. However, climate model projections for Central America are inconsistent, exhibiting substantial inter-model heterogeneity and, more fundamentally, climate model hindcasts of precipitation deviate markedly from observations. These highlight major issues with our understanding of the processes controlling hydroclimate and thus the likelihood of models capturing future changes in precipitation in this region. In this talk, I will summarize hydroclimate proxy records from western Central America and discuss results from several years of work on the Lake Izabal Basin (LIB) in eastern Guatemala, a pull-apart basin that contains more than 4 km of sediment. Outcrop observations and seismic data interpretation indicate that the basin’s sedimentological record spans several million years. Radiocarbon-dated sediment cores from Lake Izabal have provided a sneak peek into the basin’s infill, revealing an interesting Holocene record of hydroclimate change, sea-level, and ecosystem function in the northern Neotropics.

Host: Bronwen Konecky