경산호 porites lutea에 대한 산소, 탄소 동위원소 변화: 지역 고해양과 기후변화에 대한 의의

Abstract

The hard coral Porites lutes was collected near Wenno Island, in tropical Micronesia, and the stable oxygen and carbon isotope composition over the past several decades was analyzed. Soft x-ray radiographs showed clear annual bands. In all, 351 samples were analyzed in a 42.7 cm coral skeleton length; this resolution corresponds to approximately 10~15 samples per year. High-resolution results showed 24 cycles of annual variation with different amplitudes that may represent seasonal variation. Based on the cycles and annual bands, the growth rate of the coral is approximately 1.78 cm/year.The in situ instrument observations of the sea surface temperature (SST) and salinity (SSS) and the stable oxygen isotope values were relatively strongly correlated (R2 = 0.59 for SST and 0.42 for SSS). Based on these relationships, SST and SSS for the past 24 years were reconstructed, and they ranged from 28.25 to 29.9°C and from 33.4 to 43.35, respectively, which closely resemble their present ranges in the study area.Investigation of the annual linear skeleton extension (LSE) and its comparison to the isotope results showed that certain environmental factors affect the aragonite lattice, probably regional oceanographic and climatic factors. Further study including spectral analysis is necessary for accurate interpretation of the difference in the LSE.