Palaeoenvironmental reconstructions through compositional data analysis: the CoDaMAT method
We present a modern analog technique (CoDaMAT) based on compositional data analysis (Aitchison, 2003). In order to reconstruct palaeoenvironmental parameters, CoDaMAT adopts the Aitchison distance (Aitchison, 2000; 2003), obtained from relative abundances expressed in log-ratios (logarithm of ratios...
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ftunivnapoliiris:oai:www.iris.unina.it:11588/670392 2024-01-28T10:06:08+01:00 Palaeoenvironmental reconstructions through compositional data analysis: the CoDaMAT method DI DONATO, VALENTINO Martín Fernández, J. A. Cardines, C. Comas Cufí, M. D. Calcaterra, S. Mazzoli, F.M. Petti, B. Carmina & A. Zucc DI DONATO, Valentino Martín Fernández, J. A. Cardines, C. Comas Cufí, M. 2016 http://hdl.handle.net/11588/670392 https://doi.org/10.3301/ROL.2016.79 eng eng Società Geologica Italiana ispartofbook:Geosciences on a changing planet: learning from the past, exploring the future 88° Congresso della Società Geologica Italiana volume:40 issue:1 firstpage:320 lastpage:320 numberofpages:1 journal:RENDICONTI ONLINE DELLA SOCIETÀ GEOLOGICA ITALIANA alleditors:D. Calcaterra, S. Mazzoli, F.M. Petti, B. Carmina & A. Zucc http://hdl.handle.net/11588/670392 doi:10.3301/ROL.2016.79 info:eu-repo/semantics/conferenceObject 2016 ftunivnapoliiris https://doi.org/10.3301/ROL.2016.79 2024-01-02T23:50:32Z We present a modern analog technique (CoDaMAT) based on compositional data analysis (Aitchison, 2003). In order to reconstruct palaeoenvironmental parameters, CoDaMAT adopts the Aitchison distance (Aitchison, 2000; 2003), obtained from relative abundances expressed in log-ratios (logarithm of ratios), as a “natural” measure of similarity between modern and fossil assemblages. The number of modern analogs from which obtain the palaeoestimates was determined through cross-validation techniques taking modern assemblages as the training data set. Atypicality index was considered to detect past no-analog conditions. The average of distances and expected maximum estimate errors were taken into account to evaluate the quality of palaeoestimates. The method has been tested on Mediterranean and Atlantic planktonic foraminiferal assemblages to reconstruct past sea surface temperatures (SST). Due to the peculiar oceanographical asset of the Mediterranean, no-analog conditions may represent an important problem in attempting the reconstruction of glacial SST. Keeping in mind these limitations, we obtained for the Tyrrhenian sea, at 15 ka BP (during the Greenland stadial GS2-a), summer and winter SST estimates respectively 12°C and 6°C lower than present. These are the lowest values reached during the last 34 ka. In the coldest interval of the Greenland stadial GS1 (Younger Dryas), reconstructed summer and winter SST were respectively 11°C and 5°C lower than present. In comparison with previous foraminiferal based reconstructions (de Abreu et al., 2003), the CoDaMAT palaeoestimates of Atlantic ocean surface temperatures for the last 200 ka show a stronger coherence with the alkenones and stable isotope record (Pailler and Bard, 2002). Conference Object Greenland IRIS Università degli Studi di Napoli Federico II Greenland Rendiconti Online della Società Geologica Italiana 40 |
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IRIS Università degli Studi di Napoli Federico II |
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ftunivnapoliiris |
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English |
description |
We present a modern analog technique (CoDaMAT) based on compositional data analysis (Aitchison, 2003). In order to reconstruct palaeoenvironmental parameters, CoDaMAT adopts the Aitchison distance (Aitchison, 2000; 2003), obtained from relative abundances expressed in log-ratios (logarithm of ratios), as a “natural” measure of similarity between modern and fossil assemblages. The number of modern analogs from which obtain the palaeoestimates was determined through cross-validation techniques taking modern assemblages as the training data set. Atypicality index was considered to detect past no-analog conditions. The average of distances and expected maximum estimate errors were taken into account to evaluate the quality of palaeoestimates. The method has been tested on Mediterranean and Atlantic planktonic foraminiferal assemblages to reconstruct past sea surface temperatures (SST). Due to the peculiar oceanographical asset of the Mediterranean, no-analog conditions may represent an important problem in attempting the reconstruction of glacial SST. Keeping in mind these limitations, we obtained for the Tyrrhenian sea, at 15 ka BP (during the Greenland stadial GS2-a), summer and winter SST estimates respectively 12°C and 6°C lower than present. These are the lowest values reached during the last 34 ka. In the coldest interval of the Greenland stadial GS1 (Younger Dryas), reconstructed summer and winter SST were respectively 11°C and 5°C lower than present. In comparison with previous foraminiferal based reconstructions (de Abreu et al., 2003), the CoDaMAT palaeoestimates of Atlantic ocean surface temperatures for the last 200 ka show a stronger coherence with the alkenones and stable isotope record (Pailler and Bard, 2002). |
author2 |
D. Calcaterra, S. Mazzoli, F.M. Petti, B. Carmina & A. Zucc DI DONATO, Valentino Martín Fernández, J. A. Cardines, C. Comas Cufí, M. |
format |
Conference Object |
author |
DI DONATO, VALENTINO Martín Fernández, J. A. Cardines, C. Comas Cufí, M. |
spellingShingle |
DI DONATO, VALENTINO Martín Fernández, J. A. Cardines, C. Comas Cufí, M. Palaeoenvironmental reconstructions through compositional data analysis: the CoDaMAT method |
author_facet |
DI DONATO, VALENTINO Martín Fernández, J. A. Cardines, C. Comas Cufí, M. |
author_sort |
DI DONATO, VALENTINO |
title |
Palaeoenvironmental reconstructions through compositional data analysis: the CoDaMAT method |
title_short |
Palaeoenvironmental reconstructions through compositional data analysis: the CoDaMAT method |
title_full |
Palaeoenvironmental reconstructions through compositional data analysis: the CoDaMAT method |
title_fullStr |
Palaeoenvironmental reconstructions through compositional data analysis: the CoDaMAT method |
title_full_unstemmed |
Palaeoenvironmental reconstructions through compositional data analysis: the CoDaMAT method |
title_sort |
palaeoenvironmental reconstructions through compositional data analysis: the codamat method |
publisher |
Società Geologica Italiana |
publishDate |
2016 |
url |
http://hdl.handle.net/11588/670392 https://doi.org/10.3301/ROL.2016.79 |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
Greenland |
genre_facet |
Greenland |
op_relation |
ispartofbook:Geosciences on a changing planet: learning from the past, exploring the future 88° Congresso della Società Geologica Italiana volume:40 issue:1 firstpage:320 lastpage:320 numberofpages:1 journal:RENDICONTI ONLINE DELLA SOCIETÀ GEOLOGICA ITALIANA alleditors:D. Calcaterra, S. Mazzoli, F.M. Petti, B. Carmina & A. Zucc http://hdl.handle.net/11588/670392 doi:10.3301/ROL.2016.79 |
op_doi |
https://doi.org/10.3301/ROL.2016.79 |
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Rendiconti Online della Società Geologica Italiana |
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