Sea surface temperature variability during the last glacial-interglacial cycle; assessing the magnitude and pattern of climate change in the North Atlantic

Author(s): Chapman, Mark R.; Shackleton, Nicholas J.; Duplessy, Jean-Claude
Author Affiliation(s): Primary:
University of Cambridge, Godwin Laboratory, Cambridge, United Kingdom
Other:
CNRS/CEA, Gif-sur-Yvette, France
Volume Title: Palaeogeography, Palaeoclimatology, Palaeoecology
Source: Palaeogeography, Palaeoclimatology, Palaeoecology, 157(1-2), p.1-25. Publisher: Elsevier, Amsterdam, Netherlands. ISSN: 0031-0182 CODEN: PPPYAB
Note: In English. 62 refs.; illus., incl. 3 tables, sketch map
Summary: Sea surface temperature and salinity estimates reconstructed using planktonic foraminiferal abundance and δ18O records from core SU90-03 (40°N, 32°W, 2475m water depth) reveal large climatic fluctuations linked to major instabilities in Northern Hemisphere ice sheets over the last 150000 years. Episodes of enhanced ice rafted detritus (IRD) input were accompanied by discrete temperature minima, representing coolings of between 4 and 8°C, and reductions in surface salinity of up to 2.5-3.5 per mil. Several additional cooling episodes of a similar magnitude were documented during intervals of low IRD input that appear to be synchronous, within the limits of dating, with ice rafting events spatially confined to higher latitudes. Accelerator mass spectrometer 14C dates for Heinrich events (H1--14.2 ka, H2--21.4 ka, H3--26.7 ka, H4--34.8 ka, H5--47.2 ka) obtained from core SU90-03 agree well with other published age estimates and suggest a contemporaneous pattern of climate change throughout the North Atlantic during the last glacial period. This interpretation is supported by a comparison of IRD and palaeotemperature records from DSDP site 609 and core SU90-03, which clearly shows that the major climatic fluctuations identified at high latitudes were transmitted toward the subtropics. However, 14C dates suggest that ice rafting episodes may be diachronous to some extent. The northward migration of the polar front after the H1 event at 40°N in the mid-Atlantic occurred at 14 ka, approximately 500 years earlier than along the Portuguese margin, where the southerly advection of polar waters persisted within eastern boundary current system. Abstract Copyright (2000) Elsevier, B.V.
Year of Publication: 2000
Research Program: DSDP Deep Sea Drilling Project
Key Words: 03 Geochronology; 24 Surficial Geology, Quaternary Geology; Absolute age; Accelerator mass spectroscopy; Atlantic Ocean; C-14; Carbon; Cenozoic; Climate change; Cooling; Cores; Dates; Foraminifera; Glacial environment; Globigerina; Globigerina bulloides; Globigerinacea; Globigerinidae; Globigerinoides; Globigerinoides ruber; Globorotalia; Globorotalia inflata; Globorotaliidae; Heinrich events; Ice rafting; Interglacial environment; Invertebrata; Isotope ratios; Isotopes; Last glacial maximum; Marine sediments; Mass spectroscopy; Neogloboquadrina; Neogloboquadrina pachyderma; North Atlantic; O-18/O-16; Oxygen; Paleo-oceanography; Paleocirculation; Paleoclimatology; Paleocurrents; Paleotemperature; Planktonic taxa; Protista; Quaternary; Radioactive isotopes; Rotaliina; Sea-surface temperature; Sediments; Spectroscopy; Stable isotopes; Upper Quaternary
Coordinates: N400000 N400000 W0320000 W0320000
Record ID: 2000027146
Copyright Information: GeoRef, Copyright 2017 American Geosciences Institute. Reference includes data from CAPCAS, Elsevier Scientific Publishers, Amsterdam, Netherlands