USGS Scientists set out to unlock the mysteries of prehistoric droughts in the Caribbean

Release Date:

Scientists spent the last two weeks collecting sediment cores from Lake Enriquillo, a hypersaline lake in the Western Dominican Republic. The sediment cores will help scientists reconstruct the frequency of Caribbean drought and determine the controls on hydroclimate during the Holocene.

Lake Enriquillo is a large hypersaline lake in the western Dominican Republic near the border with Haiti. A group of scientists from the USGS St. Petersburg Coastal and Marine Science Center and the Florence Bascom Geoscience Center spent the past two weeks collecting sediment cores from the lake, for the purpose of reconstructing the rainfall history in Hispanola.

The team recovered 5 meters of sediment from the depocenter of the lake (making the new cores the longest cores reported from the lake, to date), and were able to target seven different coring sites within the lake. One of the primary objectives of this project is to reconstruct the frequency of Caribbean drought using paleoclimate proxies (e.g., the geochemistry of different sedimentary components in the cores), and to determine the controls on Caribbean hydroclimate during the Holocene. This is important, not only for resource management in the U.S. Caribbean (i.e., Puerto Rico & USVI), but also for understanding long-term variations in global-scale processes that impact precipitation patterns in the continental U.S. (e.g., El Niño South Oscillation and Atlantic Multidecadal Oscillation). The team was also about the collect sediment cores along a shoreward transect, which may enable them to expand the project to reconstruct paleo-shorelines (our knowledge of lake level changes is really limited to the satellite era), and event-driven deposition (tectonic and fluvial events).

Core from Lake Enriquillo, Dominican Republic, showing the laminated sediments

This core from Lake Enriquillo, Dominican Republic, shows the laminated lakebed sediments (Chucho, a local Dominican boat driver, is shown in the background).

(Credit: Dr. Wilson Ramirez, University of Puerto Rico Mayguez. Public domain.)

Jessica Rodysill (Reston) and Hunter Wilcox (SPCMSC) deploying a corer in Lake Enriquillo.

Jessica Rodysill (Reston) and Hunter Wilcox (SPCMSC) deploying a corer in Lake Enriquillo.

(Credit: Julie Richey, USGS. Public domain.)

 

Coring in Lake Enriquillo, Dominican Republic

This is one of three 4–5 meter long sediment cores recovered from the deepest part of Lago Enriquillo (95 feet water depth). This sediment core most likely represents the late Holocene (~5000 years ago to present), and the scientists will use it to construct precipitation changes in Dominican Republic over that time period. 

Pictured: (front) Dr. Wilson Ramirez, University of Puerto Rico Mayguez; (back, left to right) Sarah Kwon (SPCMSC), Dr. Julie Richey (SPCMSC), Dr. Jessica Rodysill (Florence Bascom Geoscience Center-USGS Reston), Hunter Wilcox (SPCMSC) and Jennifer Flannery (SPCMSC).

(Credit: Julie Richey, USGS. Public domain.)

 

 

 

Related Content

Filter Total Items: 1
Date published: February 22, 2018
Status: Active

Climate and Environmental Change in the Gulf of Mexico and Caribbean

This project documents paleoceanographic, climatic, and environmental changes in the Gulf of Mexico and adjacent land areas over the last 10,000 years. The paleoenvironmental data is used to determine rates of change in the past, and to better understand both the natural and anthropogenic factors that contribute to climate variability on inter-annual to millennial timescales.