Zanclean flood (Wikipedia)
The Zanclean flood or Zanclean deluge is a flood theorized to have refilled the Mediterranean Sea 5.33 million years ago. (…) The Mediterranean Basin flooded mostly during a period estimated to have been between several months and two years. Sea level rise in the basin may have reached rates at times greater than ten metres per day (thirty feet per day). Based on the erosion features preserved until modern times under the Pliocene sediment, Garcia-Castellanos et al. estimate that water rushed down a drop of more than 1 kilometre (0.6 mi) with a maximum discharge of about 100 million cubic metres per second (3.5 billion cubic feet per second), about 1000 times that of the present-day Amazon River. Studies of the underground structures at the Gibraltar Strait show that the flooding channel descended gradually toward the bottom of the basin rather than forming a steep waterfall.