Sea (Meaning and Explanation)

We explain everything about the sea, what types exist and their depth. Also, differences with the ocean and examples of world seas.

Since ancient times, the sea has provided us with transportation and food.

What are the seas?

The surface of our planet is three-quarters covered by water, forming the enormous masses of salt water that we know as oceans, and those smaller ones, known as seas.

That is to say that a sea is a body of salt water of local or regional importance much smaller in perspective than the ocean in which it is inserted. Its dimensions, shape and portion surrounded by dry land can be extremely varied.

Some bodies of salt water, instead of being called seas, are called gulfs, bays, or other names. In principle, this is due to historical considerations, since human populations have always chosen since ancient times to settle next to the sea, given the facilities for transportation, food and mild climate that its coasts usually offer.

For a long time there was talk of “the seven seas” to refer to the different known maritime regions, but in reality Their number amounts to more than fifty endowed with a gigantic diversity in terms of shapes, sizes and ecosystems. Even endorheic lakes, that is, saltwater lakes completely encapsulated in dry land, are often referred to as seas.

The seas have been an object of inspiration for humanity since very early on, motivating artistic works, incredible stories and calling the adventurer to travel. They are often attributed a feminine, if not maternal, presence, given that life began among their waters. They are often assumed to be the setting for underwater kingdoms or mythical submerged civilizations, such as Atlantis.

Difference between sea and ocean

The Oman Sea is part of the enormous Arabian Sea, in the Indian Ocean.

Said in the simplest way possible, the difference between seas and oceans is size. Almost all seas, in fact, are part of some specific ocean, so it could be said that the oceans are a larger or superior maritime unit.

There are, therefore, five oceans in the world: Atlantic, Pacific, Indian, Arctic and Antarctic; but more than fifty seas spread across the globe.

Sea depth

beaufort sea alaska canada polar bear — Life proliferates in the shallowest layers of the sea.

Both the oceans and the seas have an average depth of 4.26 kilometers distributed very unevenly. In some locations the sea may be flatter, while in other regions it extends deep into oceanic trenches and continental trenches.

For example, the Mariana Trench, located in the western Pacific Ocean, has a maximum depth recorded in the Challenger Deep, of 10,994 meters deep.

Types of seas

sea of japan korea — The Sea of Japan is located between that country and China, Korea and Russia.

The seas are classified into three types, depending on their geographical location and characteristics:

Littoral or coastal seas These are very wide gulfs on the ocean coast, which do not have any type of underwater separation from the open ocean, but have wider tides, shallower depth and higher temperatures.
continental seas Their name comes from the fact that they are located within a specific continent, but maintaining communication with the ocean to which they belong through a strait of some type, generally shallow. This means that there are substantial differences between the continental sea and the ocean, especially in terms of salinity and temperature. The tides of this type of sea are so small that they usually go completely unnoticed.
Closed seas They are also called endorheic lakes, as they are lakes of more or less salty water, large in size, located within a continental shelf and with little or no direct water exchange with the oceans. This causes the properties of its waters to always be very particular.

Examples of seas

Much of the Aral Sea today has become a desert.

Below we offer some examples of each type of sea listed above:

Littoral or coastal seas:

The Beaufort Sea. Located in the North Atlantic Ocean, between Alaska and the Canadian Yukon.
The Norwegian Sea. Part of the North Atlantic Ocean, located northwest of Norway and between the North and Greenland Seas.
The sea of Oman. Also called the Gulf of Oman, it is part of the enormous Arabian Sea, in the Indian Ocean, and communicates with the Persian Gulf through the Strait of Hormuz.
The Arabian Sea. The largest on the planet, it is part of the Indian Ocean and is located in the southwestern region of Asia, between Hindustan and the Arabian Peninsula. It has 3,862 square kilometers of surface.
The Coral Sea Located in the western Pacific Ocean, off the coast of Australia, where the Great Barrier Reef is located, the largest coral reef on the planet.

Continental seas:

The North Sea Belonging to the North Atlantic Ocean, it is located between the coasts of Norway and Denmark, Germany, the Netherlands, Belgium, France and the British Isles. It is connected through the English Channel to the rest of the Atlantic, to the Baltic Sea through the Kiel Channel and to the Norwegian Sea through the north.
The Mediterranean Sea Located between southern Western Europe and northern Africa, it gets its name from the fact that the classical cultures that emerged in its surroundings thought it was the center of the Earth. It is connected to the Atlantic Ocean through the Strait of Gibraltar.
The Sea of Japan Which gets its name from being between the coasts of that country and those of its neighbors China, Korea and Russia, and connects with five other regional seas through shallow straits.
The Baltic Sea Located in northern Europe, it is an inland sea of brackish water open to the North Sea and also connected to the Atlantic Ocean through the Kattegat and Skagerrak straits. It has two gulfs: Finland and Bothnia, and is the largest amber deposit in the world.