New results from the Gulf of Corinth, Greece, a continental rift zone where the first stage of ocean basin formation is taking place, show how the environmental conditions and sediment input into the rift basin changed as the Earth alternated between non-glaciated to glaciated conditions over the last 500 thousand years. Young rift basins, such as the Gulf of Corinth, are known to be sensitive recorders of past changes in climate and sea level and of the chemical and biological conditions of the waters they contain. Nonetheless, the changes observed in the Gulf of Corinth were more dramatic and complex than anticipated. The volume of sediment filling the rift basin increased dramatically when the Earth was experiencing glaciated conditions compared with periods when the Earth was not glaciated.