ENVIRONMENTAL RESPONSE TO RAPID CLIMATIC OSCILLATIONS ENVIRONMENTAL RESPONSE TO RAPID CLIMATIC OSCILLATIONS

METHODS

Multi-proxy analyses will be carried out on calcareous lake deposits along an west-east transect in NW-Europe. Analyses will comprise oxygen isotopes, pollen, chironomids, while AMS

C dating and tephra are used for correlation.

LOCATIONS

ENVIRONMENTAL RESPONSE TO RAPID CLIMATIC OSCILLATIONS ENVIRONMENTAL RESPONSE TO RAPID CLIMATIC OSCILLATIONS

IN NW

IN NW - - EUROPE DURING GREENLAND INTERSTADIAL 1 EUROPE DURING GREENLAND INTERSTADIAL 1

OXYGEN ISOTOPES

AIM: Correlation of sites with NGRIP

METHOD: High-resolution (~20 yrs) oxygen isotope analyses on bulk carbonates

POLLEN

AIM: Local and regional vegetation reconstruction

METHOD: Pollen analyses on the same stratigraphic levels as oxygen isotopes

CHIRONOMIDS

AIM: Temperature reconstruction

METHOD: Chironomid analyses on the same stratigraphic levels as oxygen

isotopes. Mean July air temperature can be estimated using a transfer-function.

TEPHRA

AIM: Chronology, testing of synchroneity

METHOD: Analyses on

selected samples, in which f.i. Laacher See Tephra

(12.900 yr BP) is expected

LEADS AND LAGS BETWEEN CLIMATE AND ENVIRONMENT LEADS AND LAGS BETWEEN CLIMATE AND ENVIRONMENT

Nelleke van Asch and Wim Z. Hoek

Department of Physical Geography, Faculty of Geosciences, Utrecht University. E-mail: N.vanAsch@geo.uu.nl

REFERENCES

Brooks, S.J. and Birks, H.J.B. (2000), Chironomid-inferred Late-glacial air temperatures at Whitrig Bog, southeast Scotland. Journal of Quaternary Science 15, p. 759-764.

Diefendorf, A.F. et al. (2006), Evidence for high-frequency late Glacial to mid-Holocene (16,800 to 5500 cal yr BP) climate variability from oxygen isotope values of Lough Inchiquin, Ireland. Quaternary research 65, p. 78-86.

Hoek, W.Z. (2001), Vegetation response to the ~14.7 and ~11.5 ka cal. BP climate transitions: is vegetation lagging climate? Global and Planetary change 30, p. 103-115.

Rasmussen, S. O., et al. (2006), A new Greenland ice core chronology for the last glacial termination, J. Geophys. Res., 111, D06102, doi:10.1029/2005JD006079.

-44 -42 -40 -38 -36 14

15 12

13 Age (kyr BP)

δ

O ‰ SMOW

OXYGEN ISOTOPES

NGRIP, Greenland

-9 -8 -7

10 11 12 13 14 15 16 17

GS 1

GI 1d GI 1b

Age (cal kyr BP)

δ

O ‰ VPDB

180 140 100

7.5 9.0 10.5 200

240 220 160 120 80

260

July temperature (°C) 12.0 Arboreal pollen (%)

15 12 11

13

14

0 100

CHIRONOMID INFERRED TEMPERATURE

Whitrig Bog, Scotland

POLLEN

The Netherlands

OXYGEN ISOTOPES

Lough Inchiquin, Ireland

CORRELATION BETWEEN SITES AND PROXIES

Different proxies show changes within Greenland Interstadial 1. However, leads and lags cannot be established due to the lack of a common dating framework.

© EuroGeographics

for the administrative boundaries

Multi-proxy approach → (a)synchroneity of climatic and related environmental changes within sites

E-W transect → difference in timing and amplitude of climatic and environmental changes between sites

Brooks and Birks (2000) Rasmussen et al. (2006) Diefendorf et al. (2006) Hoek (2001)

Depth (cm) Age

(cal kyr BP)

Sampling sites Ireland: ?

Britain: Whitrig Bog

The Netherlands: Empe Germany: ?

AMS ¹⁴ C DATING

AIM: Chronology

METHOD: Dating of

terrestrial macro remains

INTRODUCTION

Rapid climatic oscillations are recorded in the Greenland oxygen isotope records during GI-1 (the Bølling-Allerød or Lateglacial Interstadial). What is the effect on the terrestrial environment?

The Netherlands Organisation for Scientific Research (NWO) funded this 4-years PhD project which will run to 2011.

RESEARCH QUESTIONS

• Did temperature changes during Greenland Interstadial 1 occur synchronous in a west- east transect?

• Can we determine a west-east gradient in the amplitude of temperature changes associated with a decreasing Atlantic influence?

• Did changes in vegetation occur synchronous to temperature changes?