TY - JOUR
T1 - A progressively wetter early through middle Holocene climate in the eastern lowlands of Guatemala
AU - Duarte, Edward
AU - Obrist-Farner, Jonathan
AU - Correa-Metrio, Alex
AU - Steinman, Byron A.
N1 - Publisher Copyright:
© 2021 Elsevier B.V.
PY - 2021/5/1
Y1 - 2021/5/1
N2 - Climate records from Central America and the Caribbean region reveal considerable spatiotemporal complexity in precipitation variability, with multiple hypotheses explaining the likely ocean-atmosphere processes influencing precipitation in the region. Here we report on findings from a 760-cm long sediment core from Lake Izabal, eastern Guatemala that affords insight on regional hydroclimate change over the last ∼9,500 years. We utilized a radiocarbon-based age-depth model integrated with lithological, XRF elemental abundances, and principal component analyses to infer changes in erosion/precipitation, lake productivity, and lake water chemistry. Abundance of elements commonly associated with terrigenous sources increase from the early to the latest mid-Holocene, from ca. 9,500 to ca. 4,800 calibrated years before present (cal yr BP), suggesting a progressive increase in erosion/precipitation. This is followed by relatively stable and high erosion/precipitation conditions until ca. 1,200 cal yr BP, with an abrupt decrease in erosion/precipitation ∼1,200 years ago. Comparison of the Izabal record with other paleoclimate records from Central America and the Caribbean region indicates substantial heterogeneity in hydroclimate, even across relatively short distances, likely due to a combination of topographic complexity and the combined influences of Atlantic and Pacific basin ocean-atmosphere dynamics. Our results suggest that the progressive increase in boreal autumn insolation throughout the middle and late Holocene may have driven an increase in Caribbean sea-surface temperatures (SST) during the late wet season, leading to increased moisture availability through enhanced evaporation and greater precipitation amounts associated with zonal convergence and orographic uplift along the eastern coast of Central America. However, other nearby records demonstrate hydroclimate changes that are at least partially at odds with the Izabal record, indicating that the modern SST relationships with atmospheric circulation, including Intertropical Convergence Zone dynamics, and precipitation alone cannot be used as a framework for explaining hydroclimate variability across Central America during the Holocene.
AB - Climate records from Central America and the Caribbean region reveal considerable spatiotemporal complexity in precipitation variability, with multiple hypotheses explaining the likely ocean-atmosphere processes influencing precipitation in the region. Here we report on findings from a 760-cm long sediment core from Lake Izabal, eastern Guatemala that affords insight on regional hydroclimate change over the last ∼9,500 years. We utilized a radiocarbon-based age-depth model integrated with lithological, XRF elemental abundances, and principal component analyses to infer changes in erosion/precipitation, lake productivity, and lake water chemistry. Abundance of elements commonly associated with terrigenous sources increase from the early to the latest mid-Holocene, from ca. 9,500 to ca. 4,800 calibrated years before present (cal yr BP), suggesting a progressive increase in erosion/precipitation. This is followed by relatively stable and high erosion/precipitation conditions until ca. 1,200 cal yr BP, with an abrupt decrease in erosion/precipitation ∼1,200 years ago. Comparison of the Izabal record with other paleoclimate records from Central America and the Caribbean region indicates substantial heterogeneity in hydroclimate, even across relatively short distances, likely due to a combination of topographic complexity and the combined influences of Atlantic and Pacific basin ocean-atmosphere dynamics. Our results suggest that the progressive increase in boreal autumn insolation throughout the middle and late Holocene may have driven an increase in Caribbean sea-surface temperatures (SST) during the late wet season, leading to increased moisture availability through enhanced evaporation and greater precipitation amounts associated with zonal convergence and orographic uplift along the eastern coast of Central America. However, other nearby records demonstrate hydroclimate changes that are at least partially at odds with the Izabal record, indicating that the modern SST relationships with atmospheric circulation, including Intertropical Convergence Zone dynamics, and precipitation alone cannot be used as a framework for explaining hydroclimate variability across Central America during the Holocene.
KW - Lake Izabal
KW - autumn insolation
KW - elemental abundances
KW - precipitation
KW - sea surface temperatures
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U2 - 10.1016/j.epsl.2021.116807
DO - 10.1016/j.epsl.2021.116807
M3 - Article
AN - SCOPUS:85100994189
SN - 0012-821X
VL - 561
JO - Earth and Planetary Science Letters
JF - Earth and Planetary Science Letters
M1 - 116807
ER -