Publication Date:
2016-09-28
Description:
Due to their outstanding resolution and well-constrained chronologies, Greenland ice-core records
provide a master record of past climatic changes throughout the Last InterglacialeGlacial cycle in the
North Atlantic region. As part of the INTIMATE (INTegration of Ice-core, MArine and TErrestrial records)
project, protocols have been proposed to ensure consistent and robust correlation between different
records of past climate. A key element of these protocols has been the formal definition and ordinal
numbering of the sequence of Greenland Stadials (GS) and Greenland Interstadials (GI) within the most
recent glacial period. The GS and GI periods are the Greenland expressions of the characteristic
DansgaardeOeschger events that represent cold and warm phases of the North Atlantic region,
respectively. We present here a more detailed and extended GS/GI template for the whole of the Last
Glacial period. It is based on a synchronization of the NGRIP, GRIP, and GISP2 ice-core records that allows
the parallel analysis of all three records on a common time scale. The boundaries of the GS and GI periods
are defined based on a combination of stable-oxygen isotope ratios of the ice (d18O, reflecting mainly
local temperature) and calcium ion concentrations (reflecting mainly atmospheric dust loading)
measured in the ice. The data not only resolve the well-known sequence of DansgaardeOeschger events
that were first defined and numbered in the ice-core records more than two decades ago, but also better
resolve a number of short-lived climatic oscillations, some defined here for the first time. Using this
revised scheme, we propose a consistent approach for discriminating and naming all the significant
abrupt climatic events of the Last Glacial period that are represented in the Greenland ice records. The
final product constitutes an extended and better resolved Greenland stratotype sequence, against which
other proxy records can be compared and correlated. It also provides a more secure basis for investigating
the dynamics and fundamental causes of these climatic perturbations.
Type:
Article
,
PeerReviewed
Format:
text
DOI:
10.1016/j.quascirev.2014.09.007
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