Mediterranean Sea

The Mediterranean Sea is a large body of water between Europe, Asia, and Africa. It is almost surrounded by land, linking to the Atlantic Ocean through the Strait of Gibraltar and to the Black Sea through the Bosporus. It also connects to the Red Sea through the Suez Canal. The Mediterranean covers about 2.5 million square kilometres and includes many smaller seas like the Aegean, Adriatic, Tyrrhenian, and Marmara.

This area has been important for a long time. Many early civilizations, such as those in Egypt, Greece, and the Fertile Crescent, grew here. The sea was a major trade route, helping people share ideas, goods, and cultures. The Roman Empire once ruled all the lands around the Mediterranean.

The Mediterranean has an average depth of about 1,500 metres, with its deepest point over 5,000 metres in the Calypso Deep. It has a mild climate with warm summers and cooler, wetter winters. Many countries, including Spain, France, Italy, Greece, Turkey, Egypt, and Morocco, have coastlines along its shores. The sea also has many islands, the largest being Sicily and Sardinia.

Names and etymology

The Mediterranean Sea has had many names throughout history. The Romans called it Mare Magnum ("Great Sea") or Mare Nostrum ("Our Sea"). The term Mare Mediterrāneum means 'in the middle of land, inland' in Latin.

In Modern Arabic, it is known as al-Baḥr [al-Abyaḍ] al-Mutawassiṭ, 'the [White] Middle Sea'. The Ancient Egyptians called it Wadj-wr/Wadj-Wer/Wadj-Ur, meaning 'great green'. The Ancient Greeks often simply called it ἡ θάλασσα ('the Sea').

Different cultures gave the sea various names based on their geography and history. The Ancient Iranians called it the "Roman Sea", while in Turkish it is known as Akdeniz, meaning 'the White Sea'.

History

Main article: History of the Mediterranean region

Major ancient civilizations lived around the Mediterranean Sea. The sea helped people trade, travel, and get food from fishing. Some of the earliest advanced civilizations were the Egyptians and the Minoans, who traded a lot with each other. Later, the Greek city-states and the Phoenicians also used the sea for trade and settling new areas.

After the Punic Wars, the Roman Republic became very powerful in the Western Mediterranean. The Romans called the sea Mare Nostrum, meaning "Our Sea," because they controlled almost all of it for many years.

During the Middle Ages, new powers like the Byzantine Empire and later the Arabs influenced the area. They brought new foods like sugarcane, rice, and oranges to places such as Spain and Sicily. Trade continued between Europe and Asia, even though there were wars and changes in power.

In more recent times, the Mediterranean has been important for trade and travel. The opening of the Suez Canal in 1869 changed trade routes, making the Mediterranean very busy. In the 20th century, wars affected the sea and its nearby lands.

In recent years, the Mediterranean has seen many people trying to cross from Africa to Europe. Some boats have had trouble, and many people have not made it across the sea. Europe has tried to help those traveling across the sea.

Geography

Main article: List of islands in the Mediterranean Sea

A picture shows the Mediterranean Sea. The Strait of Gibraltar is on the bottom left, between the Iberian Peninsula in Europe and Morocco in Africa.

The Dardanelles strait in Turkey separates parts of Europe and Asia.

The Mediterranean Sea connects to the Atlantic Ocean through the Strait of Gibraltar, which also separates Europe from Africa. It connects to the Sea of Marmara and the Black Sea by the Straits of the Dardanelles and the Bosporus. The Suez Canal links it to the Red Sea.

The coastline of the Mediterranean is very long.

The Mediterranean Sea has 15 smaller seas. It stretches from the Strait of Gibraltar in the west to the Dardanelles and the Suez Canal in the east. It is surrounded by Europe, Africa, and Asia. It has two deep parts.

The basin of the Mediterranean has many rivers. The Nile is the longest. Other important rivers include the Rhône, Ebro, Po, and Maritsa.

Countries with coastlines on the Mediterranean Sea include Spain, France, Italy, Malta, Monaco, Slovenia, Croatia, Bosnia and Herzegovina, Montenegro, Albania, and Greece in Europe; Turkey, Syria, Lebanon, Israel, Palestine, and Cyprus in the Middle East; and Morocco, Algeria, Tunisia, Libya, and Egypt in North Africa.

The International Hydrographic Organization divides the Mediterranean into smaller water bodies, including the Strait of Gibraltar, Alboran Sea, Balearic Sea, Ligurian Sea, Tyrrhenian Sea, Ionian Sea, Adriatic Sea, and Aegean Sea.

The Mediterranean has many islands, with about 250 that people live on.

Much of the Mediterranean coast has mild winters and hot summers. Rarely, tropical storms can form in the sea from September to November.

Seabed

The Mediterranean Sea has many interesting underwater features shaped by the movement of Earth's plates. The African Plate moves under the Eurasian Plate, creating natural divisions in the sea. The Malta Escarpment separates the western and eastern parts, stretching from Sicily to the Maltese islands.

The western Mediterranean includes three main underwater areas. The Alboran Basin lies between Morocco and Spain. The Algerian Basin stretches from Algeria to France and has deep parts. The Tyrrhenian Basin is between Italy and the islands of Sardinia and Corsica.

The eastern Mediterranean also has several underwater basins. The Ionian Basin is south of Italy, Albania, and Greece. The Levantine Basin lies south of Anatolia. The Aegean Sea is north of Crete, bordered by Turkey and Greece. The Adriatic Sea is northwest of the main body, bordered by countries like Italy, Slovenia, and Croatia.

The Malta Escarpment is a long underwater cliff formed by tectonic forces. It features deep valleys and rich marine life.

Oceanography

Evaporation in the Mediterranean Sea is much higher than rainfall or water flowing into it from rivers. This makes the water saltier, especially in the eastern part. The average salt level is about 38 PSU.

The water in the deepest parts of the sea is quite cold, around 13.2 °C. The sea gets most of its water from the Atlantic Ocean through the Strait of Gibraltar. Without this, the sea level would drop each year.

Water moves around the Mediterranean in a pattern. Cool water from the Atlantic flows in and moves eastward along the northern African coast. Some of this water turns north towards Corsica before leaving. In the eastern part, the water warms up and becomes saltier, making it heavier. This heavier water sinks and forms a layer called Levantine Intermediate Waters (LIW). These waters move west along the coasts of Greece and southern Italy. After passing through the Strait of Sicily, they flow along the coasts of Italy, France, and Spain before leaving through the Strait of Gibraltar.

Deep water in the Mediterranean comes from three main places: the Adriatic Sea, the Aegean Sea, and the Gulf of Lion. Strong winter winds cause very cold water to sink, creating new deep water. This mixing of old and new water takes about 100 years.

The Mediterranean is very sensitive to climate change. Since the 1950s, temperatures in the sea have been rising. Climate change may cause less rain and more evaporation, leading to higher salinity. This can affect how water moves and the chemistry of the sea. Warmer temperatures can also impact sea life.

Biogeochemistry

The Mediterranean Sea has many different plants and animals, but not much food for them. This makes it hard for plants and animals to grow well there.

Some parts of the sea have more food than others. Near the coast and where rivers flow into the sea, there is more food for plants to grow. In the winter, strong winds and rain mix the water and bring up more food for tiny plants called phytoplankton. But in the summer, the water gets warm and stays on top, so there is less food. Most plants in the sea grow a little deeper down, not on the surface. The sea also has more of one kind of food than another, which affects which tiny plants and animals can live there.

Geology

See also: Geology and paleoclimatology of the Mediterranean Basin

The geologic history of the Mediterranean Sea is very interesting. It used to be thought that the sea was part of an ancient ocean called the Tethys Ocean, but we now know it is a younger basin called the Neotethys. This younger basin formed when the African Plate and Eurasian Plate moved together during the Late Triassic and Early Jurassic.

Because the Mediterranean is almost surrounded by land and has a dry climate, it loses a lot of water through evaporation. This led to a big event called the Messinian salinity crisis, when the sea became landlocked and almost dried up about six million years ago. There are thick layers of salt on the bottom of the sea from that time.

The sea was filled again about 5.3 million years ago in a huge flood called the Zanclean flood. Water rushed in from the Atlantic Ocean through the Strait of Gibraltar very quickly.

The Mediterranean Sea is not very deep on average, but its deepest point, the Calypso Deep in the Ionian Sea, is over 5,000 meters deep. The coastline of the Mediterranean is very long, stretching for about 46,000 kilometers. There is a shallow area between the island of Sicily and the coast of Tunisia that splits the sea into two parts: the Western Mediterranean and the Eastern Mediterranean.

Messinian salinity crisis

During times when the land moved, the ways that connected the Mediterranean to the Atlantic Ocean gradually closed. This happened several times, and one of these closures led to the Messinian salinity crisis. The sea level dropped a lot, and huge amounts of salt built up.

This crisis started about 5.96 million years ago and lasted for around 630,000 years. It ended when the Atlantic Ocean filled the basin again through the Strait of Gibraltar, in an event called the Zanclean flood.

Desiccation and exchanges of flora and fauna

See also: Pleistocene megafauna and Dwarf elephant

The way the Mediterranean connects to the Atlantic Ocean changed over time. Earlier connections closed, which also caused drops in sea level. These events allowed plants and animals to move between Africa and Europe. Many large animals were able to travel between the continents.

Today, the Mediterranean loses more water through evaporation than it gains from rain and rivers. This makes the water in the Mediterranean saltier than the Atlantic Ocean. The saltier water from the Mediterranean flows under the less salty water from the Atlantic Ocean when they meet at the Strait of Gibraltar.

Paleoclimate

The Mediterranean Sea changes a lot with the Earth's climate because of its special place surrounded by land. Scientists look at layers of mud and dirt in the sea to learn about old climates. These layers tell us if the area was dry or wet long ago, helping us understand the weather from millions of years back. This also helps us know when the Earth's magnetic field changed direction in the past.

Biodiversity

The Mediterranean Sea has many different plants and animals. Its currents keep the water stable, making a good home for sea creatures. Scientists think there are over 17,000 types of marine life in the Mediterranean, especially near the shore.

Most of the sea's plants and animals came from the Atlantic Ocean. Over millions of years, they adapted to the warmer waters of the Mediterranean. The Alboran Sea, where the Mediterranean meets the Atlantic, has species from both areas. One special resident is the Mediterranean monk seal, found in the Aegean Sea in Greece.

While there used to be orcas in the Mediterranean, they are not found there today.

See also: Specially Protected Areas of Mediterranean Importance, List of fishes of the Mediterranean Sea, and List of fishes of the Black Sea

Environmental issues

For thousands of years, people have changed the land around the Mediterranean Sea. This has made the area look very different from long ago. The land has always been changing in many ways.

The weather and plants in this area have changed over time. Some trees were cut down long ago. Big farms changed the land, but then many people left when the Roman Empire ended. Today, many forests are gone, and the weather keeps changing.

In recent years, more people have built homes and towns along the coasts. This has hurt the natural habitats. Many traditional ways of farming have stopped, which also changes the landscape.

The Mediterranean Sea is where the earth’s plates push and pull together. This can cause earthquakes, big waves called tsunamis, and underwater landslides. These can be dangerous for people living near the coast. Climate change is also making storms and flooding worse.

Many new plants and animals have come to the Mediterranean Sea from far away, especially through a man-made waterway called the Suez Canal. These newcomers compete with the native plants and animals.

As the world warms up, the Mediterranean Sea is expected to rise. This could flood some coastal areas and islands. Wetlands and special places for animals could be lost.

The Mediterranean Sea has a lot of pollution. Many things like sewage and oil are poured into the water every year. This hurts the fish and other sea life. One type of sea mammal, the Mediterranean monk seal, is in trouble because of pollution.

Many ships travel through the Mediterranean Sea, carrying lots of oil. Sometimes accidents happen, and oil spills can damage the water and the creatures that live there.

The beaches and coastlines of the Mediterranean are popular places for people to visit. Today, millions of tourists come every year. This brings money but can also hurt the environment. Too many buildings and visitors can damage the beaches, the water, and the homes of animals like sea turtles and seals.

There is not enough fish in the Mediterranean Sea. Many fish populations are very low because people have been catching too many fish. The warm waters of the Mediterranean are getting warmer because of climate change. This has caused many sea animals to die off.