The land and sea mentioned here is the most famous one, that is, the Mediterranean between Europe, Asia and Africa. Hebrews and ancient Greeks called it the ocean. The ancient Romans regarded it as the central sea of the Roman Empire. English, French, Spanish, Portuguese and Italian mean "the ocean in the middle of the land". China's ancient book "Answering the Generation Beyond the Ridge" called the Mediterranean Sea a great food sea in the West.
The Mediterranean Sea is 4,000 kilometers long from east to west, and its widest point from north to south is 1800 kilometers, covering an area of about 2.52 million square kilometers. Average water depth 1494m, and maximum water depth is 5530m. The northern coastline is tortuous, with many bays, and the southern coastline is relatively straight.
The Mediterranean seabed topography is characterized by a narrow continental shelf, steep slopes and deep-sea basins divided by ridges. Iberian Peninsula, Apennine Peninsula and Balkan Peninsula, which protrude southward in Europe, divide the northern Mediterranean into Ligurian Sea, Adriatic Sea and Aegean Sea. An underwater ridge between Sicily and the northern end of Tunisia divides the Mediterranean Sea into two parts. There are arvo basin, Algerian basin and tyrrhenian sea basin in the west; There are Ionian basin and Levant basin in the east. The Adriatic Sea is only tens to hundreds of meters deep, the Ionian Basin is 3000 to 4000 meters deep, and the Aegean Sea is dotted with islands.
With regard to the origin of the Mediterranean Sea, seafloor spreading and plate theory believe that it is the residual waters of the Tethys Sea (ancient Mediterranean Sea). In the Middle Ages, the Tethys Sea gradually narrowed. Today's Mediterranean is caused by the complex relative movement between the African plate and the Eurasian plate from Mesozoic to Cenozoic Miocene.
Meteorology is famous for its "Mediterranean climate", which is characterized by hot and dry summer, warm and humid winter, changeable weather in spring and short autumn. Because this climate feature is the most widely distributed and typical in the Mediterranean region, all this type of climate in the world is called "Mediterranean climate". In addition, the prevalence of strong winds is another major climate feature of the Mediterranean.
Because evaporation is greater than precipitation and runoff, the water level in the Mediterranean is lower than that in the Atlantic, and the salinity is higher. The average salinity of the surface layer is about 38‰.
Since ancient times, the Mediterranean Sea has been a channel for exchanges and trade between Europe, Asia and Africa. The Mediterranean route from Suez Canal to the Strait of Gibraltar is one of the busiest waterways in the world. There are Beirut, Port Said, Alexandria, Algiers, Marseille, Barcelona, Genoa, Naples and other ports along the coast. The Mediterranean is rich in algae, as well as economic organisms such as dolphins, lobsters, oysters and crabs, squid, jellyfish and corals. The coast is also a good place to dry salt.