Age models of northern North Atlantic sediment cores


Autoria(s): Thornalley, David JR; Elderfield, Henry; McCave, I Nick
Cobertura

MEDIAN LATITUDE: 62.244833 * MEDIAN LONGITUDE: -18.085500 * SOUTH-BOUND LATITUDE: 61.466000 * WEST-BOUND LONGITUDE: -19.533000 * NORTH-BOUND LATITUDE: 62.975500 * EAST-BOUND LONGITUDE: -17.134000

Data(s)

09/04/2010

Resumo

Benthic foraminiferal stable isotope records from four high-resolution sediment cores, forming a depth transect between 1237 m and 2303 m on the South Iceland Rise, have been used to reconstruct intermediate and deep water paleoceanographic changes in the northern North Atlantic during the last 21 ka (spanning Termination I and the Holocene). Typically, a sampling resolution of ~100 years is attained. Deglacial core chronologies are accurately tied to North Greenland Ice Core Project (NGRIP) ice core records through the correlation of tephra layers and changes in the percent abundance of Neogloboquadrina pachyderma (sinistral) with transitions in NGRIP. The evolution from the glacial mode of circulation to the present regime is punctuated by two periods with low benthic d13C and d18O values, which do not lie on glacial or Holocene water mass mixing lines. These periods correlate with the late Younger Dryas/Early Holocene (11.5-12.2 ka) and Heinrich Stadial 1 (14.7-16.8 ka) during which time freshwater input and sea-ice formation led to brine rejection both locally and as an overflow exported from the Nordic seas into the northern North Atlantic, as earlier reported by Meland et al. (2008). The export of brine with low ?13C values from the Nordic seas complicates traditional interpretations of low d13C values during the deglaciation as incursions of southern sourced water, although the spatial extent of this brine is uncertain. The records also reveal that the onset of the Younger Dryas was accompanied by an abrupt and transient (~200-300 year duration) decrease in the ventilation of the northern North Atlantic. During the Holocene, Iceland-Scotland Overflow Water only reached its modern flow strength and/or depth over the South Iceland Rise by 7-8 ka, in parallel with surface ocean reorganizations and a cessation in deglacial meltwater input to the North Atlantic.

Formato

application/zip, 3 datasets

Identificador

https://doi.pangaea.de/10.1594/PANGAEA.831630

doi:10.1594/PANGAEA.831630

Idioma(s)

en

Publicador

PANGAEA

Direitos

CC-BY: Creative Commons Attribution 3.0 Unported

Access constraints: unrestricted

Fonte

Supplement to: Thornalley, David JR; Elderfield, Henry; McCave, I Nick (2010): Intermediate and deep water paleoceanography of the northern North Atlantic over the past 21,000 years. Paleoceanography, 25(1), PA1211, doi:10.1029/2009PA001833

Palavras-Chave #Age, 14C AMS; Age, comment; Age, dated; Age, dated standard deviation; Age dated; Age model; Age std dev; Calendar age before AD 2000; Comm; Depth; DEPTH, sediment/rock; no reservoir applied; SUERC (Scottish Universities Environmental Research Centre) = 14C dates run by the UK NERC radiocarbon facility in Glasgow
Tipo

Dataset