Advances in Geosciences www.adv-geosci.net 1680-7340 1680-7359 6 1st Alexander von Humboldt International Conference 2006 10.5194/adgeo-6-23-2006 http://www.adv-geosci.net/6/23/2006/ http://www.adv-geosci.net/6/23/2006/adgeo-6-23-2006.html http://www.adv-geosci.net/6/23/2006/adgeo-6-23-2006.pdf 23 27 2006-01-09 ENSO and interdecadal climate variability over the last century documented by geochemical records of two coral cores from the South West Pacific T. Ourbak T. Corrège B. Malaizé F. Le Cornec K. Charlier J. P. Peypouquet Département de Géologie et Océanographie (DGO), UMR CNRS 5805 EPOC, Université Bordeaux 1, Avenue des facultés, 33405 Talence cedex, France Institut de Recherche pour le Développement (IRD) UR055 Paleotropique 32, avenue Henri Varagnat 93143 Bondy cedex, France The south west Pacific is affected by climatic phenomena such as ENSO (El Ni&#241;o Southern Oscillation) or the PDO (Pacific Decadal Oscillation). Near-monthly resolution calibrations of Sr/Ca, U/Ca and <span style="font-family: 'Symbol, Times New Roman, Times'; font-size: 16px;">&delta;</span>¹⁸Oc were made on corals taken from New Caledonia and Wallis Island. These geochemical variations could be linked to SST (sea surface temperature) and SSS (sea surface salinity) variations over the last two decades, itselves dependent on ENSO occurrences. On the other hand, near-half-yearly resolution over the last century smoothes seasonal and interannual climate signals, but emphasizes low frequency climate variability.