Collina-Girard's hypothesis states that during the most recent Glacial Maximum of the Ice Age sea level was 135 m below its current level, narrowing the Gibraltar Strait and creating a small half-enclosed sea measuring 70 km by 20 km between the Mediterranean and Atlantic Ocean. The Spartel Bank formed an archipelago in this small sea with the largest island measuring about 10 to 12 kilometers across. With rising ocean levels the island began to slowly shrink, but then at around 9400 BC (11,400 years ago) there was an accelerated sea level rise of 4 meters per century known as Meltwater pulse 1A, which drowned the top of the main island. The occurrence of a great earthquake and tsunami in this region, similar to the 1755 Lisbon earthquake (magnitude 8.5-9) was proposed by marine geophysicist Marc-Andrè Gutscher as offering a possible explanation for the described catastrophic destruction (reference — Gutscher, M.-A., 2005. Destruction of Atlantis by a great earthquake and tsunami? A geological analysis of the Spartel Bank hypothesis. Geology, v. 33, p. 685-688.) . Collina-Girard proposes that the disappearance of this island was recorded in prehistoric Egyptian tradition for 5,000 years until it was written down by the first Egyptian scribes around 4000-3000 BC, and the story then subsequently inspired Plato to write a fictionalized version interpreted to illustrate his own principles.