Surface and deep-water hydrography on Gardar Drift (Iceland Basin) during the last interglacial period

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doi: 10.1016/j.epsl.2009.08.040
Author(s): Hodell, David A.; Minth, Emily Kay; Curtis, Jason H.; McCave, I. Nicholas; Hall, Ian R.; Channell, James E. T.; Xuan, Chuang
Author Affiliation(s): Primary:
University of Cambridge, Department of Earth Sciences, Cambridge, United Kingdom
University of Florida, United States
Cardiff University, United Kingdom
Volume Title: Earth and Planetary Science Letters
Source: Earth and Planetary Science Letters, 288(1-2), p.10-19. Publisher: Elsevier, Amsterdam, Netherlands. ISSN: 0012-821X CODEN: EPSLA2
Note: In English. 60 refs.; illus., incl. sketch map
Summary: Changes in surface and deep-water hydrography were inferred from variations in stable isotopes and sortable silt mean grain size, respectively, on the southern Gardar Drift in the subpolar North Atlantic. The bathymetric δ13C gradient during the penultimate glaciation was similar to the last glaciation with high- δ13C Glacial North Atlantic Intermediate water above ≈2000 m, and low- δ13C water derived from the Southern Ocean below. During Termination II, low-δ13C water was present throughout the water column with minimum values at intermediate depths (≈1500-2000 m) and below 3000 m. This pattern continued well into the early part of the Last Interglacial (LIG) period. Sortable silt mean size at 3275 m suggests that deep-water circulation on Gardar Drift was relatively weak during the earliest part of the LIG (128 to 124.5 ka) when planktonic δ18O was at a minimum, reflecting warming and/or reduced salinity. We suggest that low-δ13C water and slow current speed on Gardar Drift during the early part of the LIG was related to increased melt water fluxes to the Nordic Seas during peak boreal summer insolation, which decreased the flux and/or density of overflow to the North Atlantic. The resumption of the typical interglacial pattern of strong, well-ventilated Iceland Scotland Overflow Water was delayed until ≈124 ka. These changes may have affected Atlantic Meridional Overturning Circulation. Abstract Copyright (2009) Elsevier, B.V.
Year of Publication: 2009
Research Program: IODP Integrated Ocean Drilling Program
Key Words: 24 Surficial Geology, Quaternary Geology; Atlantic Ocean; Bathymetry; C-13/C-12; Carbon; Cenozoic; Clastic sediments; Density; Expeditions 303/306; Foraminifera; Gardar Drift; Granulometry; IODP Site U1304; Iceland Basin; Iceland Scotland Overflow Water; Insolation; Integrated Ocean Drilling Program; Interglacial environment; Invertebrata; Isotope ratios; Isotopes; Meltwater; Microfossils; North Atlantic; North Atlantic Deep Water; North Atlantic Oscillation; Northeast Atlantic; O-18/O-16; Ocean circulation; Oxygen; Paleo-oceanography; Paleocurrents; Pleistocene; Protista; Quaternary; Salinity; Sedimentation rates; Sediments; Silt; Stable isotopes; Thermohaline circulation
Coordinates: N530300 N530300 W0333200 W0333200
Record ID: 2010038745
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from CAPCAS, Elsevier Scientific Publishers, Amsterdam, Netherlands