Precise 14 C ages of the Vedde and Saksunarvatn ashes and the Younger Dryas boundaries from western Norway and their comparison with the Greenland Ice Core ( GICC05) chronology

• Published in: Journal of Quaternary Science
• Main Authors: LOHNE, ØYSTEIN S., MANGERUD, JAN, BIRKS, HILARY H.
• Other Authors: Centre for climate dynamics at the Bjerknes Centre, Research Council of Norway, 14C dates from core 46
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2013
• Subjects: Greenland; Greenland ice core; Greenland ice cores; ice core
• Online Access: http://dx.doi.org/10.1002/jqs.2640; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fjqs.2640; https://onlinelibrary.wiley.com/doi/pdf/10.1002/jqs.2640

ABSTRACT The Greenland ice cores with the GICC05 chronology represent a standard for late Quaternary climate events and their ages, whereas many other palaeoclimatic archives are dependent on 14 C dates. It is therefore critical to know if the ice‐core and the calibrated 14 C chronologies are identical, and if not to quantify the offset between them. We present Bayesian age–depth modelling of 118 accelerator mass spectrometry 14 C dates from Kråkenes Lake, calibrated using INTCAL09, that provide high precision ages of 12 066 ± 42 and 10 210 ± 35 cal a BP for the Vedde and Saksunarvatn ashes, respectively. The lower and upper Younger Dryas boundaries have ages of 12 710 ± 52 and 11 546 ± 59 cal a BP, respectively. The four dated levels coincide with correlative levels in GICC05 within the dating uncertainties, but are all consistently younger at Kråkenes. The ages of the tephra chronostratigraphic markers suggest a mean offset of ∼70 years to older ages in the GICC05 compared with the INTCAL09 time scale. Responses to small climate changes ∼30 years before the Younger Dryas boundaries at Kråkenes are suggested to correspond to the defined Greenland Stadial 1 boundaries. This suggested difference in timing (30 years) and time scale offset (70 years) mean that the Greenland Stadial 1 boundaries appear ∼100 years older than the Younger Dryas boundaries.