Robert C. Thunell

Senior Associate Dean for Natural Sciences
Carolina Distinguished Professor
Department of Earth and Ocean Sciences
Paleoceanography, Paleoclimatology, Deep Sea Sediments

A.B., 1973 Brown University;
M.S., 1975, Ph. D., 1978, University of Rhode Island;
Postdoctoral Fellow, 1978-1979, Woods Hole Oceanographic Institution
 

Research Areas: Reconstructing paleoceanographic and paleoclimatic conditions using deep sea sediments; measuring the production and flux of sediments in the ocean; calibration of paleoclimate proxies.  For laboratory facilities see Marine Sediments Research Lab

Paleoceanographic/ Paleoclimatic Reconstructions: The marine sedimentary record contains perhaps the best long-term archive of global climate change. Using a variety of analytical techniques, including micropaleontology, sediment geochemistry and stable isotope geochemistry, we are trying to reconstruct the paleoceanographic and paleoclimatic conditions that existed in various regions during the Neogene. Our current emphasis is on high resolution (decadal to century-scale) studies of late Pleistocene climate. This type of research is currently being carried out in the Gulf of California, offshore California, the southern Caribbean, the western North Atlantic, and the Indonesian region.

Sediment Production and Fluxes: Through the use of moored sediment traps, we are studying temporal variability in the production and flux of sediments in the ocean. In particular, we are studying seasonal to interannual changes in sediment flux in response to climate forcing and changing upper ocean conditions. Current sediment trapping studies in Santa Barbara Basin and the Gulf of California are designed to study the impact of ENSO on sedimentation in these regions. A third trapping program in Cariaco Basin is examining carbon fluxes in a coastal upwelling regime. Additionally, in all three of these regions sediment laminae are preserved on the sea floor due to anoxic bottom conditions and our sediment trap work is allowing us to model varve formation in these basins.

Climate Proxy Development and Calibration: Reconstructing the history of the oceans is dependent on our ability to reliably extract from the sediment record information on physical, chemical and biological processes. Our sediment trapping work is contributing to the development and calibration of various climate proxies. For example, we are studying the oxygen isotopic composition of multiple species of planktonic foraminifera in order to use this as a tool for reconstructing upper ocean thermal structure in the past.

Recent Publications:

Montes, E., Muller-Karger, F., Thunell, R. and others, 2012. Vertical fluxes of particulate biogenic material through the euphotic and twilight zones in the Cariaco Basin, Venezuela, Deep Sea Research 67, 73-84

Hertzberg, J., Black, D., Peterson, L., Thunell, R., and Haug, G., 2012. Decadal- to centennial-scale tropical Atlantic climate variability across a Dansgaard-Oeschger cycle, Paleoceanography 27, PA3218, doi:10.1029/2011PA002251.

Ren, H., Sigman, D., Thunell, R and Prokopenko, M., 2012. Nitrogen isotopic composition of planktonic foraminifera from the modern ocean and recent sediments, Limnology and Oceanography 57, 1011-1024.

Cronin, T., Rayburn, J., Guilbault, J., Thunell, R. and Franzi, D., 2012. Stable isotope evidence for glacial lake drainage through the St. Lawrence Estuary, eastern Canada, ~ 13.1-12.9 ka, Quaternary International 260, 55-65.

Pichevin, L., Ganeshram, R., Reynolds, B., Prahl, F., Pedersen, T., Thunell, R., and McClymont, E., 2012. Silicic acid biogeochemistry in the Gulf of California: Insights from sedimentary Si isotopes. Paleoceanography 27, PA2201, doi: 10.1029/2011PA002237..

McClymont, E., R. Ganeshram, L. Pichevin, H. Talbot, B. van Dongen, R. Thunell, A. Haywood, J. Singarayer and P. Valdes, 2012. Sea-surface temperature records of Termination 1 in the Gulf of California: challenges for seasonal and inter-annual analogues of tropical Pacific climate change, Paleoceanpgraphy 27, PA2202, doi:10.1029/2011PA002226.

Black, D., Thunell, R., Wejnert, K. and Astor, Y., 2011. Carbon isotope composition of Caribbean Sea surface waters: Response to the uptake of anthropogenic CO2, Geophysical Research Letters 38, L16609, doi: 10.1029/2011GL048538.

Khider, D., Stott, L.D., Emile-Geay, J., Thunell, R., Hammond, D.E., 2011. Assessing El Niño Southern Oscillation variability during the past millennium, Paleoceanography 26, PA3222, doi:10.1029/2011PA002139.

Pusz, A., Thunell, R. and Miller, K., 2011. Deep water temperature, carbonate ion, and ice volume changes across the Eocene-Oligocene climate transition, Paleoceanography 26, PA2205, doi:10.1029/2010PA001950..

Newton, A., Thunell, R. and Stott, L., 2011. Changes in the Indonesian Throughflow during the past 2000 years, Geology 39, 63-66.

Cronin, T., Hayo, K., Thunell, R., Dwyer, G., Saenger, C. and Willard, D., 2010. The Medieval climate anomaly and Little Ice Age in Chesapeake Bay and the North Atlantic Ocean, Palaeogeography, Palaeoclimatology, Palaeoecology 297, 299-310.

Wejnert, K., Pride, C., and Thunell, R., 2010. The oxygen isotope composition of planktonic foraminifera from Guaymas Basin, Gulf of California: Seasonal, annual and interspecies variability, Marine Microplaeontology 74, 29-37.

Martinez, N., Murray, R., Thunell, R., Peterson, L., Muller-Karger, F., Lorenzoni, L., Astor, Y., and Varela, R., 2010. Local and regional chemical signatures of surface sediments of the Cariaco Basin and Orinoco Delta, Venezuela, Geology. 38, 159-162.

Saikku, R., Stott, L. and Thunell, R., 2009. A bipolar signal recorded in the western tropical Pacific: Northern and Southern Hemisphere climate records from the Pacific Warm Pool during the last ice age, Quaternary Science Reviews 28, 2374-2385.

McConnell, M., Thunell, R., Lorenzoni, L., Astor, Y., Wright, J. and Fairbanks, R., 2009. Seasonal variability in the salinity and oxygen isotopic composition of seawater from the Cariaco Basin, Venezuela: Implications for paleosalinity reconstructions, Geochemistry, Geophysics, Geosystems 10, doi:10.1029/2008GC002035

Sekula-Wood, E., Schnetzer, A., Benitez-Nelson, C., …Thunell, R. 2009. Rapid downward transport of the neurotoxin domoic acod on coastal waters, Nature Geoscience, doi:10:1038/NGEO472

Romero, O., Thunell, R., Astor, Y. and Varela, R., 2009. Seasonal and interannual dynamics in diatom production in the Cariaco Basin, Venezuela, Deep-Sea Research 56, 571-581.

Thunell, R., Benitez-Nelson, C., Muller-Karger, F., Lorenzoni, L.,, Fanning, K., Scranton, M., Varela, R. and Astor, Y., 2008. Si cycle in the Cariaco Basin, Venezuela: Seasonal variability in silicate availability and the Si:C:N composition of sinking particles, Global Biogeochemical Cycles, vol. 22, doi:10.1029/2007GB003096.

Black, D., Abahazi, M., Thunell, R., Kaplan, A., Tappa, E. and Peterson, L., 2007. An 8-century tropical Atlantic SST record from the Cariaco Basin: Baseline variability, twentieth-century warming, and Atlantic hurricane frequency, Paleoceanography 22, PA4204, doi:10.1029/2007PA001427.

Stott, L., Timmermann, A. and Thunell, R., 2007. Southern hemisphere and deep-sea warming led deglacial atmospheric CO2 rise and tropical warming, Science 318, 435-438.

Bob Thunell
Dept. of Earth and Ocean Sciences
700 Sumter Street
Univ. of South Carolina
Columbia, SC 29208

Phone: 803 777-7593
FAX: 803 777-4525
Internet: thunell@geol.sc.edu