Speleothem Paleoclimate Records from the Isthmus of Panama

Our research group on Central American and Mexican paleoclimate consists of faculty and students at the University of Nevada, Las Vegas, UMass-Amherst, the University of New Mexico, the Smithsonian Tropical Research Institute, and the Universidad Autónoma de Mexico (UNAM). Our work is funded by the National Science Foundation's Earth Systems History program, and analyses are done at the Las Vegas Isotope Science Lab, which was funded by the NSF MRI program. See Publications for recent papers and abstracts of our research.

Introduction

Speleothems hold promise for neotropical paleoclimate studies because there are no high altitude ice cores or carbonate-rich lakes available for isotopic study. Pollen studies have yielded much information on broad-scale vegetation and climate variations but are of generally low resolution, and coral records, while of high resolution, are commonly limited in temporal duration. Because of a stable cave climate and rainfall-derived δ¹⁸O records, speleothems can be considered the 'ice cores of the lowland tropics'. Unlike ice cores however, speleothems have the benefit that they can be precisely dated by U/Th radiometric methods, and hence can provide comparable or better isotopic records. Moreover, speleothems are widespread and can be collected and analyzed in replicate at a fraction of the cost associated with ice core programs, giving a high 'data to dollar' ratio.

Our most recent research is in Central Mexico, which is a climatically-sensitive location because it is located on the northern fringe of the Intertropical Convergence Zone (ITCZ). The location is also of interest because the region is the epicenter of the domestication of maize (teosinte), and the numerous pre-conquest civilizations (Maya, Olmec, Aztec, others) that have occupied the region during the Holocene.

Site Map of the Isthmus of Panama and Costa Rica, with location of some speleothem study areas.