Paleoceanography and Paleoclimatology Lab
School of Marine and Atmospheric Sciences,
Stony Brook University
Cariaco Basin (current research):
The Cariaco Basin is a small pull-apart basin located on the northern continental
shelf of Venezuela, and is the second-largest anoxic basin in the world after the
Black Sea. The combination of restricted water exchange with the open Caribbean
and intense seasonal productivity results in the water being anoxic below about 250
meters. The anoxia and strong seasonal climatology produce high-deposition rate
varved sediments with an abundance of microfossils that are perfect for performing
ultra-high resolution paleoceanographic reconstructions. Additionally, the Cariaco
Basin provides the rare opportunity to directly calibrate paleoclimate proxies against
instrumental data using down-core sediments.
There are several ongoing projects in the lab that involve material collected
from the Cariaco Basin. First, we are trying to establish baseline tropical climate
variability for the last 2000 years at a temporal resolution of one to two years
per sample. We have calibrated proxies for trade wind intensity and Intertropical
Convergence zone variability using the abundance of the planktic foraminifer Globigerina
bulloides. The G. bulloides abundance record currently extends back to about 400
AD. We are also reconstructing hydrographic conditions using stable oxygen isotopes
and Mg/Ca from foraminiferal calcite from seasonally-representative species. The
second major project in the lab is to reconstruct subcentennial-scale tropical climate
variability for a time when boundary conditions (e.g., sea level, continental ice
volume, carbon dioxide concentrations, etc.) were very different from today, and
rapidly changing. We are specifically looking at a period known as Interstadial-12
(approximately 44,000 years ago), a time when temperatures over Greenland were changing
as much as 6-8° C in as little as a few decades. This project is part of a larger
study being performed in collaboration with scientists at the University of Miami,
University of South Carolina, and University of California - Santa Barbara.
Photos from a recent Cariaco Basin cruise (May 2008). From left to right: Recovery
a box core containing sediments that will be used to calibrate paleoclimate proxies
against the instrumental record of the last 20 years, recovery of the top float/sphere
of a sediment trap, and successful recovery of mud from the box corer!
