Coral-based Holocene sea level of Paraoir, Western Luzon, Philippines

Abstract Shallow-water corals are crucial natural archives for reconstructing deglacial sea-level changes. However, significant discrepancies exist between sea-level records from different places. Here we present recently acquired 230 Th-dated coral ages between 10,256 ± 50 yr BP and 6654 ± 29 yr BP (before 1950 AD) from Paraoir, western Luzon, Philippines to document deglacial sea-level rise of the western Pacific. The results indicate that the Paraoir reef started growing 10.3 kyr BP from about 29 m below present sea level, and reached 8 m below the PSL at 7.2 kyr BP. The Paraoir sea-level records are consistent with those of northwestern Luzon and the western Australia coast; both of which are coral-based records in continental or island arc settings. But sea levels of Luzon are significantly higher than those of Tahiti, a basaltic island on oceanic crust. We propose that the differences in sea level between the Philippine and Tahiti result from spatial variations of glacial isostatic adjustment of the two sites.