Ancient Sea Level Secrets: Predicting sea level change is key to understanding coastal populations’ vulnerability to future climate shifts. Fortunately, geological records have preserved the natural swings in Earth’s climate, including the oceans’ related variations. Rapid sea-level change of 120-140 m occurred during the last deglaciation and was a dramatic global response to climate shifts and glacial melting. Tropical coral reefs offer one of the best sea level indicators, and are easily dated by radiometric methods to construct relative sea level (RSL). Such records are used in global models to understand ice-melting and sea level impacts. To date, there are only a handful of coral reef records of deglacial sea level change, but they are insufficient to properly inform predictions for the future. As a result, Professor Ken Rubin from the University of Hawaii Manoa, and co-investigators Chip Fletcher and Scott White will set out to explore sea level rise records from the last ice age using currently drowned central Pacific coral reefs. The science team will look at corals in the Hawaiian Islands (Oahu to Lanai) and Line Islands (Palmyra, Kingman), that showcase climatically important glacial melt water pulses. Hawaii and the Line Islands represent excellent sites to explore because they are far-field from meltwater sources, and lie along a geographic gradient of anticipated sea level differences. Using ROV SuBastian and an AUV, the team will be able to take high resolution images and make observations of coral colony morphology, ecology, and age. This will give us better information from which to build maps and predictions of rising seas. Learn more here.