Foraminiferal Assemblages Reveal Multiple Super-Interglacials during the Mid-Pleistocene Transition, Ross Sea, Antarctica

Presenter

Erin Kim

Campus

UMass Amherst

Sponsor

R. Mark Leckie, Department of Earth, Geographic and Climate Sciences, UMass Amherst

Schedule

Session 1, 10:30 AM - 11:15 AM [Schedule by Time][Poster Grid for Time/Location]

Location

Poster Board A8, Campus Center Auditorium, Row 1 (A1-A20) [Poster Location Map]

Abstract

The Mid-Pleistocene Transition (MPT) represents a critical phase in Earth's climatic history during which the dominant periodicity of orbital forcing shifted from a 40,000-year cycle to a 100,000-year cycle. This transition remains a topic of significant scientific interest and has prompted numerous studies to determine the underlying mechanisms. Within the MPT timeframe, Marine Isotope Stage 31 (MIS-31) emerged as a prominent super-interglacial period, exhibiting distinctive climatic and environmental characteristics. We are examining planktic and benthic foraminifera from IODP Site U1523 in the Ross Sea to provide a high-resolution snapshot of the MPT, including the MIS 31 interval from Antarctica. These microfossil assemblages reveal evidence for multiple super-interglacials in the Ross Sea region between MIS 39 and MIS 25 (~1.29-0.96 Ma) based on high abundances of foraminifera through this interval. Notably, previous studies conducted in the Cape Roberts and ANDRILL projects have reported similar patterns to MIS 31. The selected foraminiferal assemblages are dominated by planktic Neogloboquadrina pachyderma and benthics Trifarina earlandi and Globocassidulina subglobosa. These species have proven valuable in paleoclimatic reconstructions due to their sensitivity to environmental changes, including variations in sea surface temperature and current activity, such as the Antarctic Slope Current (ASC). A decrease in abundance and diversity of benthics after MIS-25 may signal increased sedimentation, dilution, and/or dissolution associated with increased production of High Salinity Shelf Water (HSSW).

Keywords

Climate change, Paleoclimatology, Paleoceanography, Biostratigraphy

Research Area

Climate Science

SIMILAR ABSTRACTS (BY KEYWORD)