2:37 PM - 2:52 PM
[MIS19-10] Reconstruction of paleoenvironments in the western Pacific for the last 220 years
Keywords:the western Pacific, coral skeleton, paleoclimate
Here, we present a 224-year SST record with high time resolution (~2 month) derived from Sr/Ca ratios and stable isotopes (δ18O andδ13C) from Philippines (13°N, 124°E), which located on the northern edge of the western pacific warm pool (WPWP).
Coral Sr/Ca was measured by an inductively coupled plasma optical/atomic emission spectrometer (ICP-OES/AES) with a precision was better than 0.6 % which is equivalent to 0.5 ℃. Analyses of δ18O and δ13C were measured by isotope ratio mass spectrometer (IR-MS). Precision was better than 0.05 ‰ for δ13C and 0.10 ‰ for δ18O . In this study, spectral analysis was performed by using the kSpectra.
Reconstructed SST varies from 25 to 32 ℃ and shows that there were multiple cold events during the last 224 years in the western tropical Pacific. A decreasing trend in δ13C for the last 50 years was found which may reflect accelerated increase in the amount of anthropogenic CO2 (Suess effect).The result of δ18O analyses implies western pacific climate was cooler and drier in the early 19th century which is almost consistent with other coral records. In contrast, warmer and wetter conditions persist since 1950s.The spectral analysis of the annual SST and δ18O anomaly for 224 years shows significant peaks at 3-8 years. These frequencies are considered to be related to the ENSO variability.