Climatic variability during the last millennium in Western Iceland from lake sediment records
Climatic variability during the last millennium in Western Iceland from lake sediment records
The aim of this research was to create a decadal scale terrestrial quantitative palaeoclimate record for NW Iceland from lake sediments for the last millennium. Geochemical, stable isotope and chironomid reconstructions were obtained from a lake sequence constrained by tephra deposits on the Snæfellsnes peninsula, W Iceland. Obtaining a quantitative record proved problematic, but the qualitative chironomid record showed clear trends associated with past summer temperatures, and the sedimentological records provided evidence for past changes in precipitation, mediated through catchment soil inwash. When the full range of chronological uncertainty is considered, four clear phases of climatic conditions were identified: (1) a relatively warm phase between AD 1020 – 1310; (2) a relatively stable period between AD 1310 and AD 1510, cooler than the preceding period, but still notably warmer that the second half of the millennium; (3) a consistent reduction of temperatures between AD 1560 – 1810, with the coolest period between AD 1680-1810; (4) AD 1840-2000 has temperatures mainly warmer than in the preceding two centuries, with a rising trend and increased variability from c. AD 1900 onwards. The reconstructions show clearly that the first half of the millennium experienced warmer climatic conditions than the second half, with a return to the warmer climate only occurring in the last c. 100 years. Much of the variability of the chironomid record can be linked to changes in the North Atlantic Oscillation (NAO). The reconstructions presented can track low frequency and long-term trends effectively and consistently but high resolution and calibrated quantitative records remain more of a challenge – not just in finding optimal sedimentary deposits, but also in finding the most reliable proxy. It is this that presents the real challenge for Holocene climate reconstruction from this key area of the North Atlantic.
iceland, palaeolimnology, chironomids, little ice age, medieval climate anomaly, north atlantic oscillation
756-771
Holmes, N.
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Langdon, P.G.
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Caseldine, C.J.
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Wastegård, S.
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Leng, M.J.
d3b48578-3020-44f7-a088-827aef7502e7
Croudace, I.W.
24deb068-d096-485e-8a23-a32b7a68afaf
Davies, S.M.
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May 2016
Holmes, N.
104f8a3d-6f08-409b-b187-725493b75a0f
Langdon, P.G.
95b97671-f9fe-4884-aca6-9aa3cd1a6d7f
Caseldine, C.J.
5ee86ca4-a6d2-4c5b-88ae-068b294a54af
Wastegård, S.
5c01a086-db18-4d4c-aa23-8679edd2b86b
Leng, M.J.
d3b48578-3020-44f7-a088-827aef7502e7
Croudace, I.W.
24deb068-d096-485e-8a23-a32b7a68afaf
Davies, S.M.
eeea5fcd-404a-45e3-b4d5-34d1ae68bf89
Holmes, N., Langdon, P.G., Caseldine, C.J., Wastegård, S., Leng, M.J., Croudace, I.W. and Davies, S.M.
(2016)
Climatic variability during the last millennium in Western Iceland from lake sediment records.
The Holocene, 26 (5), .
(doi:10.1177/0959683615618260).
Abstract
The aim of this research was to create a decadal scale terrestrial quantitative palaeoclimate record for NW Iceland from lake sediments for the last millennium. Geochemical, stable isotope and chironomid reconstructions were obtained from a lake sequence constrained by tephra deposits on the Snæfellsnes peninsula, W Iceland. Obtaining a quantitative record proved problematic, but the qualitative chironomid record showed clear trends associated with past summer temperatures, and the sedimentological records provided evidence for past changes in precipitation, mediated through catchment soil inwash. When the full range of chronological uncertainty is considered, four clear phases of climatic conditions were identified: (1) a relatively warm phase between AD 1020 – 1310; (2) a relatively stable period between AD 1310 and AD 1510, cooler than the preceding period, but still notably warmer that the second half of the millennium; (3) a consistent reduction of temperatures between AD 1560 – 1810, with the coolest period between AD 1680-1810; (4) AD 1840-2000 has temperatures mainly warmer than in the preceding two centuries, with a rising trend and increased variability from c. AD 1900 onwards. The reconstructions show clearly that the first half of the millennium experienced warmer climatic conditions than the second half, with a return to the warmer climate only occurring in the last c. 100 years. Much of the variability of the chironomid record can be linked to changes in the North Atlantic Oscillation (NAO). The reconstructions presented can track low frequency and long-term trends effectively and consistently but high resolution and calibrated quantitative records remain more of a challenge – not just in finding optimal sedimentary deposits, but also in finding the most reliable proxy. It is this that presents the real challenge for Holocene climate reconstruction from this key area of the North Atlantic.
Text
Baularvallavatn_revised v1.docx
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More information
Accepted/In Press date: 12 October 2015
e-pub ahead of print date: 6 January 2016
Published date: May 2016
Keywords:
iceland, palaeolimnology, chironomids, little ice age, medieval climate anomaly, north atlantic oscillation
Organisations:
Geochemistry, Geography & Environment
Identifiers
Local EPrints ID: 384385
URI: http://eprints.soton.ac.uk/id/eprint/384385
ISSN: 0959-6836
PURE UUID: e139f006-0652-48d8-8430-e5b9b5d6e4f5
Catalogue record
Date deposited: 25 Nov 2015 11:27
Last modified: 15 Mar 2024 02:57
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Contributors
Author:
N. Holmes
Author:
C.J. Caseldine
Author:
S. Wastegård
Author:
M.J. Leng
Author:
S.M. Davies
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