International Ocean Discovery Program

Expedition 325: Great Barrier Reef Environmental Changes

January – March 2010

The GBREC expedition is designed to establish the course and effects of the last glaciation in reef settings that developed in tectonically inactive areas located far from glaciated regions. Expedition 325 proposes to core at several osshore sites along transects on the Great Barrier Reef. Key objectives are  to reconstruct the deglaciation curve for the period 20Kyrs-10Kyrs before present in order to establish the minimum sea level during the Last Glacial Maximum (LGM) and to assess the validity, timing and validity of meltwater pulses which are thought to have disturbed the general thermohaline oceanic circulation and hence global climate.

The expedition also aims to establish the sea-surface temperature variation which accompanied the transgression. These data will enable the impact of sea-level rise on reef growth, geometry and biological makeup to be assessed. The patterns of short term palaeoclimatic changes are thought to punctuate the transitional period between present-day climatic conditions following the LGM.

Petrophysics Staff Scientist


  • Yokoyama Y., Webster J.M., Cotterill C., Braga J.C., Jovane L., Mills H., Morgan S., Suzuki A. and the IODP Expedition 325 Scientists. 2011. IODP Expedition 325: Great Barrier Reefs Reveals Past Sea-Level, Climate and Environmental Changes Since the Last Ice Age. Scientific Drilling, No. 12, September 2011, 32-145.
  • Harper, B.B., Puga-Bernabéu, Á., Droxler, A.W., Webster, J.M., Gischler, E., Tiwari, M., Lado-Insua, T., Thomas, A.L., Morgan, S. & Jovane, L. 2015. Mixed Carbonate–Siliciclastic Sedimentation Along the Great Barrier Reef Upper Slope: A Challenge To the Reciprocal Sedimentation Model. Journal of Sedimentary Research, 85, 1019-1036.
  • Hinestrosa, G., Webster, J.M., Beaman, R.J. & Anderson, L.M. 2014. Seismic stratigraphy and development of the shelf-edge reefs of the Great Barrier Reef, Australia. Marine Geology, 353, 1-20, doi: 10.1016/j.margeo.2014.03.016.

As Petrophysics Staff Scientist, Louise Anderson is a co-author on the following expedition-related publications:

Preliminary report

  • Expedition 325 Scientists, 2010. Great Barrier Reef environmental changes: the last deglacial sea level rise in the South Pacific: offshore drilling northeast Australia. IODP Prel. Rept., 325. doi:10.2204/

Scientific Drilling Journal

  • Yokohama, Y., Webster, J.M., Cotterill, C., Braga, J.C., Jovane, L., Mills, H., Morgan, S., Suzuki, A., and the IODP Expedition 325 Scientists, 2011. IODP Expedition 325: the Great Barrier Reef reveals past sea-level, climate, and environmental changes since the last Ice Age. Sci. Drill., 12:32–45.

Expedition proceedings

  • Webster, J.M., Yokoyama, Y., Cotterill, C., and the Expedition 325 Scientists, 2011. Proc. IODP, 325: Tokyo (Integrated Ocean Drilling Program Management International, Inc.). doi:10.2204/iodp.proc.325.2011

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