Background to the ANDRILL Southern McMurdo Sound Project, Antarctica

• Main Authors: FLORINDO, F., HARWOOD, D., TALARICO, F. M., LEVY, R. H., SMS SCIENCE TEAM
• Other Authors: Florindo, F., Harwood, D., Talarico, F. M., Levy, R. H., SMS SCIENCE, Team
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2009
• Subjects: Antarc*; Antarctic; Antarctica; East Antarctica; Ice Sheet; McMurdo Sound; ice covered areas
• Online Access: http://hdl.handle.net/11365/8205

During the austral spring of 2007, the Southern McMurdo (SMS) Project recovered a 1138.54 meter long drill core (AND-2A) from a 8.5 m thick floating seaice platform (~8.5 meters thick) over approximately 380 meters of water (77°45.488S; 165°16.613E) (Fig. 1). This demonstrated the ANDRILL Program’s continuing success in recovering high quality marine and glacimarine sedimentary drill core (> 98% core recovery) from high latitude ice-covered areas. A primary goal of the SMS Project, the second drillhole of the McMurdo Sound Portfolio (Harwood et al., 2006), was to recover an Antarctic marine sediment record depositied during the middle Miocene, which has long been held as one of the fundamental time intervals in development of the modern Antarctic ice sheets (e.g., Zachos et al., 2001; Shevenell et al., 2004). Deep-sea stable isotope records suggest the middle Miocene encompassed a change from the warm Mid-Miocene Climatic Optimum (MMCO), approximately 17.5 to 14.5 million years ago (Ma), to the onset of major cooling between approximately 14.5 to 13.5 Ma, which is commonly interpreted as the major cause of the formation of a quasi-permanent ice sheet in East Antarctica (e.g., Haywood et al., 2008, and references contained therein). The AND-2A drill core, Pleistocene to early Miocene in age (e.g., Acton et al., this volume), confirms its potential to establish a robust history of Neogene Antarctic ice sheet variation and climate evolution that can be integrated into continental and global records toward a better understanding of Antarctica’s role in the past, present and future global system. In particular, the recovery of middle Miocene Antarctic stratigraphic sequences will greatly improve the evaluation of global proxy records that invoke a change from a warm climatic optimum to the onset of major Miocene cooling. The uppermost section of AND-2A core, Pliocene to Pleistocene in age, shows a similar importance in providing an original record that will complement and build on coastal and fjord sediment ...