Post-Glacial Relative Sea-Level History of Oahua and Kauai

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9317328 Fletcher An acceptable relative sea-level (RSL) history for the post- glacial period in Hawaii has not yet been proposed. Late Holocene RSL is characterized by gradually decreasing hydroisostatic uplift. New field evidence showing emergence documents the hydroisostatic deformation of Kauai, Oahu, Molokai, and probably Maui following the culmination of post-glacial RSL rise. The timing of initial emergence, its height, and it termination all appear to have an island-specific character reflecting the influence of island radius, distance from the volcanic center, and various site- specific factors. Research will focus on obtaining additional field data to constrain these variables and produce a model of hydroisostatic response along the Hawaii Ridge. Pleistocene and early Holocene RSL around Oahu and Kauai will be documented with cores from submerged shorelines. Wave-cut notches and drowned reef complexes indicate former sea-level positions at predictable depths encircling both islands. A small, hand-held pneumatic drill can sample early deposited carbonate dating former RSL. Petrographic and XRD analysis of samples will help define geologic history. Species-specific oxygen isotope contents will be determined from well preserved, dated coral samples. Variations in the oceanic oxygen isotope chemistry during the post-glacial transgression will be documented. The research will produce a detailed RSL history for Kauai and Oahu tied to changes in the stable isotope record of meltwater history.