An improved north–south synchronization of ice core records around the 41 kyr 10Be peak

Using  new  high-resolution 10Be  measurements in  the  NGRIP,  EDML  and  Vostok  ice  cores,  together  with previously  published  data  from  EDC,  we  present  an  improved synchronization between Greenland and Antarctic ice cores during the Laschamp geomagnetic excursion ∼41 kyr ago. We estimate the precision of this synchronization to be ± 20 years, an order of magnitude better than previous work. We discuss the implications of this new synchronization for making improved estimates of the depth difference between ice and enclosed gas of the same age (Ddepth), difference between age of ice and enclosed gas at the same depth (Dage) in the EDC and EDML ice cores, spectral properties of the 10Be profiles and phasing between Dansgaard–Oeschger-10 (in NGRIP) and AIM-10 (in EDML and EDC).

Fig. 1. Beryllium 10 fluxes after synchronization to NGRIP (GICC05) for EDC, EDML and Vostok. For each site the detailed fluxes (histograms calculated using 11 cm accumulation rates for NGRIP, 55 cm for EDC, 50 cm for EDML and 10 cm for Vostok) and results smoothed with a 50-year binomial filter (curve) are shown.
Fig. 2: Phasing between the GS–GIS transition in Greenland (vertical orange line) and the maximum of the AIM 10 in 4 different Antarctic ice cores on the GICC05 age scale.

Authors : G. M. Raisbeck, A. Cauquoin, J. Jouzel, A. Landais, J.-R. Petit et al.

Reference :  Clim. Past, 13, 217–229, 2017, doi:10.5194/cp-13-217-2017

 


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