ISOSTATIC ADJUSTMENT OF NORTHEASTERN KODIAK ISLAND, ALASKA SINCE THE LAST GLACIAL MAXIMUM (LGM)

Late Pleistocene glaciations of the Kodiak Archipelago were marked by the development of regional ice caps that covered most of the archipelago and adjacent continental shelf. Following the last glacial maximum (LGM) circa 23 – 17 ka deglaciation occurred rapidly. Based on radiocarbon limiting age-estimates, on Kodiak Island the ice had retreated from the continental shelf to upland portions of the island by ~13.5 ka. At Narrow Cape on the northeast part of the island retreat of the Kodiak Ice Cap triggered at least 135 meters of isostatic rebound as recorded by a raised marine limit sand. At Narrow Cape between ~13.5 ka and ~7 ka the average rate of glacio-isostatic uplift was ~17.5 m/ky, with initial rates reaching approximately 6 meters per century.