Past sea level has varied by somewhat more than a hundred metres. This is primarily due to the growth and decay of ice sheets (mostly in the northern hemisphere) with water evaporated from the sea. The Mediterranean Basin's gradual growth as the Neotethys basin, begun in the Jurassic, did not suddenly affect ocean levels. While the Mediterranean was forming during the past 100 million years, the average ocean level was generally 200 metres above current levels. However, the largest known example of marine flooding was when the Atlantic breached the Strait of Gibraltar at the end of the Messinian Salinity Crisis about 5.2
Earth and water BC. In the 6th book, Darius sent heralds throughout Hellas bidding them demand "earth and water" for the king (Hdt. 6.48). There were not many city-states that refused. In Book 7, he recounts that when the Persians sent envoys to the Spartans and to the Athenians demanding the traditional symbol of surrender, an offering of soil and water, the Spartans threw them into a well and the Athenians threw them into a gorge, suggesting that upon their arrival at the bottom, they could "Dig it out for yourselves." The demand for "earth and water" symbolized that those surrendering to Persians