The dating of the earliest successful migration of modern humans out of Africa is a matter of dispute.[3] It may have pre- or post-dated the Toba catastrophe, a volcanic super eruption that took place between 69,000 and 77,000 years ago at the site of present-day Lake Toba. According to Michael Petraglia, stone tools discovered below the layers of ash deposits in India at Jwalapuram, Andhra Pradesh point to a pre-Toba dispersal.