Geological Society of America

T102 Lacustrine Systems across Space and Time I

Monday, 23 October 2017
8:00 AM - 12:00 PM
Room 307/308

LAKE SEDIMENT RECORDS OF HOLOCENE HYDROCLIMATE VARIABILITY ACROSS THE NORTHERN TROPICAL AMERICAS

Paper number: T102-13
Program: Technical Sessions
Time: 10:55 AM – 11:15 AM

Authors

Nathan Stansell Presenting Author
Northern Illinois University, DeKalb, IL
Byron A. Steinman
University of Minnesota Duluth, Duluth, MN
Matthew Lachniet
University of Nevada Las Vegas, Las Vegas, NV
William Harvey
University of Oxford, Oxford
Jacob Feller
Northern Illinois University, DeKalb, IL
Stephen Perdziola
Northern Illinois University, DeKalb, IL
Peter Mortensen
Northern Illinois University, DeKalb, IL

Abstract

Lake sediment records from the tropical Americas provide a unique perspective of Holocene hydroclimate variability. Here, we present a synthesis of lake-level and stable isotope records along a transect from the tropical Americas with a focus on newly developed datasets from the circum-Caribbean region. There is dissimilar spatio-temporal variability in paleoclimate records across the lowland northern tropics, with some indicating a wet-dry-wet pattern, and others a dry-wet-dry pattern during the early, middle, and late Holocene. On a larger scale, hydroclimate records from the southern outer tropics appear to covary with the northern outer tropics, while lake level records of moisture-balance changes from the inner tropics from both hemispheres are generally synchronous. Thus, the available records indicate a complex, spatially-variable pattern that we argue cannot be explained as a direct response to orbital-driven solar forcing. Instead, hydroclimate variability during the Holocene is likely more of a response to non-linear responses to orbital forcing, such as regional shifts in sea-surface temperatures, ocean-atmospheric processes, and monsoon dynamics. For the last millennium, we focus on high-resolution stable isotope records and evaluate the northern tropical hydroclimate responses to the North Atlantic Oscillation (NAO) and the El Niño Southern Oscillation (ENSO).

Geological Society of America Abstracts with Programs. Vol. 49, No. 6

doi: 10.1130/abs/2017AM-299496

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