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- Björck, S., et al.
(författare)
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An event stratigraphy for the Last Termination in the North Atlantic region based on the Greenland Ice-core record: a proposal by the INTIMATE group.
- 1998
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Ingår i: Journal of Quaternary Science. - 0267-8179 .- 1099-1417. ; 13:4, s. 283-292
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Tidskriftsartikel (refereegranskat)abstract
- It is suggested that the GRIP Greenland ice-core should constitute the stratotype for the Last Termination. Based on the oxygen isotope signal in that core, a new event stratigraphy spanning the time interval from ca. 22.0 to 11.5 k GRIP yr BP (ca. 19.0-10.0 k C-14 yr BP) is proposed for the North Atlantic region. This covers the period from the Last Glacial Maximum, through Termination 1 of the deep-ocean record, to the Pleistocene-Holocene boundary, and encompasses the Last Glacial Late-glacial of the traditional northwest European stratigraphy. The isotopic record for this period is divided into two stadial episodes, Greenland Stadials 1 (GS-1) and 2 (GS-2), and two interstadial events, Greenland Interstadials 1 (GI-1) and 2 (GI-2). In addition, GI-1 and GS-2 are further subdivided into shorter episodes. The event stratigraphy is equally applicable to ice-core, marine and terrestrial records and is considered to be a more appropriate classificatory scheme than the terrestrially based radiocarbon-dated chronostratigraphy that has been used hitherto.
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| 2. |
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| 3. |
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| 4. |
- Witte, H.J.L., et al.
(författare)
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Regression coefficients of thermal gradients in northwestern Europe during the last glacial-Holocene transition using beetle MCR data.
- 1998
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Ingår i: Journal of Quaternary Science. - 0267-8179 .- 1099-1417. ; 13:5, s. 435-445
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Tidskriftsartikel (refereegranskat)abstract
- Palaeotemperature estimates obtained from 74 sites in northern Europe, and collectively spanning approximately the last 45 000 yr (radiocarbon time-scale), have been compiled as a major component of the EPECC project. The data presented here have been obtained using the mutual climatic range (MCR) method based on beetle assemblage data. The sites range across a transect from Ireland in the west to Poland and Finland in the east. Thermal gradients have been derived from the data using multiple linear regression. The regression models were solved for each of a series of 'time windows'. Each interval has a separate time-dependant trend, which was removed by detrending before solving the regression equations. The robustness and confidence intervals of the regression coefficients were estimated using the bootstrap method, with samples being selected from the data set by Monte Carlo simulation. The resulting palaeotemperature gradients were compared with modern temperature gradients over Europe. The data suggest that there were significant changes in the steepness of latitudinal temperature gradients over northern Europe during the past 45000 yr, although most attention in our compilations is focused on the last glacial-Holocene transition, the period for which the most abundant data are available so far. A significant delay in warming at the end of the last glacial stage in the northern part of the study area, by comparison with the southern sector, is also inferred. Reasons for these temporal and geographical variations and their possible palaeoclimatic implications are discussed.
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