Mediterranean Sea 5.33 mya); "see" animation: Africa-Arabia colliding with Eurasia. Accordingly, the Mediterranean basin consists of several stretched tectonic plates in subduction which are the foundation of the Eastern part of the Mediterranean Sea. Various zones of subduction harbour and form the deepest and most majestic oceanic ridges, east of the Ionian Sea and south of the Aegean. The Central Indian Ridge runs East of the Mediterranean Sea South-East across the in-between of Africa and the Arabian Peninsula into the Indian Ocean. During Mesozoic and Cenozoic times, as the northwest corner of Africa converged on Iberia, it lifted the Betic-Rif mountain belts
Mediterranean Sea is estimated that approximately 220,000 merchant vessels of more than 100 tonnes cross the Mediterranean Sea each year—about one third of the world's total merchant shipping. These ships often carry hazardous cargo, which if lost would result in severe damage to the marine environment. The discharge of chemical tank washings and oily wastes also represent a significant source of marine pollution. The Mediterranean Sea constitutes 0.7% of the global water surface and yet receives 17% of global marine oil pollution. It is estimated that every year between and of crude oil are deliberately released into the sea from shipping activities.