Paleo-se level at Windley Key, Florida

Paleo-sea level = 5.5 meters + 3.0 meters = 8.5 meters above present

On a tectonically stable coast such as the Florida Keys, we can estimate how high sea level was in the past, because fossil coral reefs give us a “high water mark” for a past interglacial period. Here at Windley Key, the top of a coral reef is 5.5 meters above modern sea level and has been dated to ~120,000 years ago (oxygen isotope stage 5), the last interglacial period. The types of corals in this reef require water depths of at least 3 meters. Thus, sea level ~120,000 years ago must have been 5.5 meters above present, plus at least 3 meters more (for habitat depth), indicating at least 8.5 meters above present.