Investigation of the sedimentary record of Antarctic climate change with a focus on Pliocene of the Weddell Sea. Today the densest ocean water, Antarctic Bottom Water, is formed in the Weddell Sea.  Yet, the sedimentary history of the Weddell Sea basin is poorly studied. Students will measure and sample these cores, and have access to examine all of the Antarctic drilled ocean cores.

What: Investigation of the sedimentary record of Antarctic climate change with a focus on Pliocene of the Weddell Sea. Today the densest ocean water, Antarctic Bottom Water, is formed in the Weddell Sea.  Yet, the sedimentary history of the Weddell Sea basin is poorly studied. Students will measure and sample these cores, and have access to examine all of the Antarctic drilled ocean cores.

When:  June 15-July 12

Where:  We will spend the first two weeks in College Station, TX at the Ocean Drilling Program Core Repository at Texas A&M University.  There we will stay in a hotel and most meals will be eaten out. Working conditions involve spending most of the day in the core repository, describing cores, using the XRF core scanner and high resolution digital scanner.  The last two days will be spent sampling cores for thesis projects. The second two weeks will be spent at Wesleyan University. Their students will begin sample analysis, access research papers and develop their thesis research plan.

 

Figure 1. Location of Expe.113 sites. White letters are the sites that are the focus. Gray circles on left are other ODP sites cored on the Antarctic Peninsula during ODP Leg 178, but overall recovery was <20% (Barker, Camerlenghi, Acton et al., 1999). Map created using GeoMapApp.

Figure 1. Location of Expe.113 sites. White letters are the sites that are the focus. Gray circles on left are other ODP sites cored on the Antarctic Peninsula during ODP Leg 178, but overall recovery was <20% (Barker, Camerlenghi, Acton et al., 1999). Map created using GeoMapApp.

Overview and Goals

Pliocene climate is difficult to explain with our present understanding of climate dynamics. Fedorov et al., (2006) calls it the Pliocene Paradox. It could also be a harbinger of Earth’s future and warmer climate. Geologic records, based on marine phytoplankton, paleosols and boron (Beerling and Royer, 2011), show that Pliocene atmospheric CO2 levels were around 400 ppm.  CO2 measurements on Mauna Loa reached 400 ppm in May of 2013.  Temperatures during the mid-Pliocene (~3.0 m.y. ago) are estimated to have been 2-3 oC warmer than today, with increased warmth concentrated in high latitudes.  In model and data based investigations, researchers have proposed that the differences in climate might be due to changes in ocean circulation (Charles et al., 1996, Jacobs et al., 2011), a permanent El Nino (Wara et al., 2005), a more extreme hydrologic cycle (Chandler et al., 1994), ocean productivity changes (Filippelli and Flores, 2009), and multiple and poorly understood feedbacks within the complex systems (e.g. Fedorov et al., 2006). Despite this effort, there is no consensus.

A large and important area of missing Pliocene data is the Antarctic Weddell Sea.  In over forty years of Ocean Drilling only two months, one expedition, 113, took place in the Weddell Sea.  These sites will be the focus of our study.  In addition to the Expedition 113 sites, all of the Deep Sea Drilling Project (DSDP), Ocean Drilling Program (ODP) and Intergrated Ocean Drilling Program (IODP) Antarctic cores are stored in College Station, Texas.  Although our focus will be the Weddell Sea, we will have access to all of the Antarctic sediment cores recovered during these programs.  Consider this a field trip to the Antarctic Core Repository.

 

Table 1. Maud Rise (689 and 690) and Weddell Sea site information and ODP sites that are part of this investigation (from Barker, Kennett, et al., 1988).

Table 1. Maud Rise (689 and 690) and Weddell Sea site information and ODP sites that are part of this investigation (from Barker, Kennett, et al., 1988).

Potential Student Projects:  Brief titles are listed.  Click on the title to get more information.  Although the focus will be on the Pliocene, if someone would prefer to investigate an older part of the Cenozoic, they are welcome to do so.  There is a rich source of thesis topics available from research on these cores. The major research method is listed below.  The science behind the research is described in detail, often with examples, in Appendix 1.

A. Weigh (<2mm) dry sample and sieve to separate coarse and size fraction.

A1- Coarse fraction (> 63 microns)

    1. Abundance (wt% or lithics/g) of IRD
    2. Composition of IRD
    3. Large diatom identification.

 A2- Fine fraction (< 63 microns)

    1. Variations in % biosilica
    2. XRD mineralogy
    3. Size distribution of < 63 um fraction

B. XRF sediment analysis for major (possibly minor) elemental oxide wt%

C. Diatoms identification for chronostratigraphy & environment.

D. Dropstone petrology

Recommended Courses/Prerequisites

No prerequisites.  The final research project selected by the student will depend upon the students background and interest of the faculty advisor.  For example, a student with a strong mineralogy and statistics background, might want to undertake analyzing the chemistry of the XRF core scanner data, a study with an interest in paleoceanography and statistics might prefer to investigate the % biosilica with the Ba/AL ratio.

 

References

Barker, P.E, Kennett, J.P., et al., 1988. Proc. ODP, Init. Repts., 113: College Station, TX (Ocean Drilling Program). doi:10.2973/odp.proc.ir.113.1988.

Beerling, D. J., and Royer, D. L., 2011, Convergent Cenozoic CO2 history: Nature Geoscience, v. 4, no. 7, p. 418.

Bond G.C., Heinrich, H., Broecker, W., Labeyrie, L., McManus, J., Andrews, J., Huon, S., Jantschik, R., Clasen, S., Simet, C., Tedesco, K., Klas, M., Bonani, G. and Ivy, S., 1992. Evidence for massive discharges of icebergs into the North Atlantic Ocean during the last glacial: Nature 360: 245-249.

Bond, G.C. and Lotti, R. 1995. Iceberg discharges into the North Atlantic on millennial time scales during the last glaciation. Science 267: 1005-1010.

Buurman, P., Pape, J. T., Reijneveld, A., de Jong, F., and van Gelder, E., 2001, Laser-diffraction and pipette-method grain sizing of Dutch sediments: correlations for fine fractions of marine, fluvial, and loess samples: Geologie en Mijnbouw / Netherlands Journal of Geosciences, v. 80, no. 2, p. 49-57.

Chandler, M., Rind, D., and Thompson, R., 1994, Joint investigations of the middle Pliocene climate II: GISS GCM Northern Hemisphere results: Global and Planetary Change, v. 9, no. 3, p. 197-219.

Charles, C. D., LynchStieglitz, J., Ninnemann, U. S., and Fairbanks, R. G., 1996, Climate connections between the hemisphere revealed by deep sea sediment core ice core correlations: Earth and Planetary Science Letters, v. 142, no. 1-2, p. 19-27.

Cook, C. P., van de Flierdt, T., Williams, T., Hemming, S. R., Iwai, M., Kobayashi, M., Jimenez-Espejo, F. J., Escutia, C., Gonzalez, J. J., Khim, B. K., McKay, R. M., Passchier, S., Bohaty, S. M., Riesselman, C. R., Tauxe, L., Sugisaki, S., Galindo, A. L., Patterson, M. O., Sangiorgi, F., Pierce, E. L., Brinkhuis, H., and Scientists, I. E., 2013, Dynamic behaviour of the East Antarctic ice sheet during Pliocene warmth: Nature Geoscience, v. 6, no. 9, p. 765-769.

DeConto, R. M., and Pollard, D., 2003, Rapid Cenozoic glaciation of Antarctica induced by declining atmospheric CO2: Nature, v. 421, no. 6920, p. 245-249.

Fedorov, A. V., Dekens, P. S., McCarthy, M., Ravelo, A. C., deMenocal, P. B., Barreiro, M., Pacanowski, R. C., and Philander, S. G., 2006, The Pliocene paradox (mechanisms for a permanent El Niño): Science (New York, N.Y.), v. 312, no. 5779, p. 1485-1489.

Filippelli, G. M., and Flores, J. A., 2009, From the warm Pliocene to the cold Pleistocene: A tale of two oceans: Geology, v. 37, no. 10, p. 959-960.

Jacobs, S. S., Jenkins, A., Giulivi, C. F., and Dutrieux, P., 2011, Stronger ocean circulation and increased melting under Pine Island Glacier ice shelf: Nature Geoscience, v. 4, no. 8, p. 519-523.

Hauptvogel, D. W., and Passchier, S., 2012, Early–Middle Miocene (17–14 Ma) Antarctic ice dynamics reconstructed from the heavy mineral provenance in the AND-2A drill core, Ross Sea, Antarctica: Global and Planetary Change, v. 82-83, p. 38-50.

Kanfoush, S., 2012, Inverse Relationship of Marine Aerosoland Dust in Antarctic Ice with Fine-Grained Sediment in the South AtlanticOcean: Implications for Sea-IceCoverage and Wind Strength: International Journal of Ocean and Climate Systems, v. 3, p. 15.

Konfirst, M. A., Scherer, R. P., Gerhard, K., and Monien, D., 2012, The influence of siliciclastic input on Chaetoceros abundance in an early Pliocene segment of the ANDRILL AND-1B drill core.: Palaeogeography, Palaeoclimatology, Palaeoecology, v. 346-347, p. 87-94.

Lyle, M., Lyle, A. O., Gorgas, T., Holbourn, A., Westerhold, T., Hathorne, E., Kimoto, K., and Yamamoto, S., 2012, Data report: raw and normalized elemental data along the Site U1338 splice from X-ray fluorescence scanning, in Pälike, H., Lyle, M., Nishi, H., Raffi, I., Gamage, K., Klaus, A., and Scientists, a. t. E., eds., Volume 320/321: College Station, TX, IODP.

Majewska, R., Gambi, M. C., and De Stefano, M., 2013a, Epiphytic diatom communities of Terra Nova Bay (Ross Sea Antarctica): structiral analysis and relations to algal hosts: Antarctic Science, v. 24, p. 501-503.

Majewska, R., Gambi, M. C., Totti, C., Pennesi, C., and De Stefano, M., 2013b, Growth form analysis of epiphytic diatom communities of Terra Nova Bay (Ross Sea, Antarctica): Polar Biology, v. 36, no. 1, p. 73-86.

Monien, D., Kuhn, G., von Eynatten, H., and Talarico, F. M., 2012, Geochemical provenance analysis of fine-grained sediment revealing Late Miocene to recent Paleo-Environmental changes in the Western Ross Sea, Antarctica: Global and Planetary Change, v. 96–97, p. 41-58.

Passchier, S., Bohaty, S., Jiménez‐Espejo, F., Pross, J., Röhl, U., Flierdt, T., Escutia, C., and Brinkhuis, H., 2013, Early Eocene to middle Miocene cooling and aridification of East Antarctica: Geochemistry, Geophysics, Geosystems.

Shaffer, G., Olsen, S.M., and Bjerrum, C.J. 2004. Ocean subsurface warming as a mechanism for coupling Dansgaard-Oeschger climate cycles and ice rafting events. Geophysical Research Letters 31: L24202.

Shipboard Scientific Party, 1988, Site 693, in Barker, P. F., Kennett, J.P., et al., ed., Proc. ODP, Init. Repts., Volume 113: College Station, TX, Ocean Drilling Program, p. 393-448.

Wara, M. W., Ravelo, A. C., and Delaney, M. L., 2005, Permanent El Niño-like conditions during the Pliocene Warm Period: Science, v. 309, no. 5735, p. 758-761.

Weltje, G. J., and Tjallingii, R., 2008, Calibration of XRF core scanners for quantitative geochemical logging of sediment cores: Theory and application: Earth and Planetary Science Letters, v. 274, p. 423-438.

 Appendix 1

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