How many seas are on earth? Nobody can tell you the exact answer. For example, the International Hydrographic Bureau identifies only 54 seas, some scientists believe that there are more than 90 seas on our planet (not counting the Caspian, Dead and Galilee, which are often referred to as lakes). The most common version is that there are still 81 seas. Such a discrepancy arises due to the fact that scientists interpret the very concept of "sea" in different ways.
The most common interpretation: sea - body of water, segregated landmasses or elevations of underwater landforms . From a geological point of view, the seas are young formations. The deepest formed at the break tectonic plates such as the Mediterranean. Smaller ones are formed on the outskirts of the continents when the continental shoals are flooded.
Characteristics of the seas
The seas are actively involved in the creation temperature regime the globe. Sea water is very "lazy" and heats up slowly. Therefore, for example, the water in the Mediterranean Sea becomes warmest not in July, when it is hot, but in September. As the level drops, the water cools down quickly. At the bottom of the deep seas- about 0ºC. While freezing salty water starts at -1.5 ºC; - 1.9 ºC.
Warm and cold currents move huge masses of water - warm or cold. This greatly affects the formation of the climate.
An important role is also played by the ebbs and flows, the frequency of their change and height. The occurrence of ebbs and flows is associated with a change in the phases of the moon.
Known interesting feature water in the sea. When immersed, the sea gradually "eats" the colors. At a depth of 6 m, scarlet colors disappear, at a depth of 45 m - orange, 90 m - yellow, at a depth of more than 100 m only purple and greenish shades remain. Therefore the most colorful undersea world located at shallow depths.
Sea types
There are several classifications that unite the seas according to certain criteria. Consider the most popular.
1. Over the oceans(list of seas by oceans)
2. By degree of isolation
Internal - do not have access to the ocean (isolated), or are connected with them through the straits (semi-isolated). In fact, isolated seas (Aral, Dead) are considered to be lakes. And the straits connecting the semi-isolated seas with the ocean are so narrow that they do not lead to mixing of deep waters. Example - Baltic, Mediterranean.
Marginal - located on the shelf, have an extensive network of underwater currents and free access to the ocean. They are separated from each other by islands or underwater hills.
Interisland - such seas are surrounded by a close group of islands that prevent connection with the ocean. Most of these seas among the islands of the Malay Archipelago are Javanese, Sulawesi.
Intercontinental - seas lying at the junction of continents - Mediterranean, Red.
3. According to the salinity of the waters distinguish slightly saline (Black) and highly saline (Red) seas.
4. By the degree of indentation of the coastline There are seas with a strongly indented and slightly indented coastline. But, for example, the Sargasso Sea has no coastline at all.
The coastlines are characterized by the presence of bays, estuaries, bays, spits, cliffs, peninsulas, beaches, fjords and headlands.
The difference between the sea and the lake, the bay and the ocean
Despite the great similarity of interpretations of the concepts "sea", "lake", "bay" and "ocean", these words are not synonymous.
So, the sea differs from the lake:
Size. The sea is always bigger.
The degree of salinity of the waters. In the sea, water is always mixed with salt, while in lakes it can be fresh, brackish and salty.
Geographic location. Lakes are always located within continents and are surrounded on all sides by land. The seas most often have a connection with the ocean.
It is more difficult to separate seas and oceans. It's all about size here. It is generally accepted that the sea is only a part of the ocean that has unique flora and fauna. The sea may differ from the ocean in the degree of salinity of the water and in relief.
The bay is also an integral part of the ocean, deeply incised into the land. Unlike the sea, it always has a free connection with the ocean. In some cases, the name of the bay was assigned to the water areas, which, according to their hydrological characteristics, are more likely to be seas. For example, Hudson Bay, California, Mexico.
The most salty sea
(The Dead Sea)
If we consider the Dead Sea as a sea, and not a lake, then the palm in terms of the degree of salinity of the waters will belong to this area. The salt concentration here is 340 g/l. Because of the salt, the density of the water is such that it is impossible to drown in the Dead Sea. By the way, this is why there are no fish and plants in the Dead Sea, in such brine only bacteria live.
Of the recognized seas, the Red Sea is considered the most salty. 1 liter of water contains 41 g of salt.
In Russia, the most salty sea is Barents (34-37g/l).
The biggest sea
(Philippine Sea)
The largest sea in the world is the Philippine (5726 thousand sq. km). Located in the western part Pacific Ocean between the Taiwan, Japanese and Philippine islands. This sea is also the deepest in the world. The greatest depth was recorded in the Mariana Trench - 11022 m. The territory of the sea immediately covers 4 climatic zones: from equatorial to subtropical.
The largest sea in Russia is Beringovo (2315 thousand sq. Km.)
Help me please!!!
Answers:
1. I love walking by the sea. They never bother me, because they are always different. The sea itself is not the same. It is changeable in nature. Today it is calm and quiet and, as if there is nothing more affectionate than its light waves. Water reflects warm Sun rays and blinds, not accustomed to bright light, eyes. Warm sand pleasantly warms my feet, and the skin is covered with a golden tan. And tomorrow the sea will stir strong wind and majestic waves are already beating against the shore with the strength of a huge beast. Blue sky becomes gray and stormy. And there is no longer that calm happiness calm sea. However, this also has its own charm. This is the beauty of wildness and power. Even the color sea water often changes - it is almost blue, then dark blue, then greenish. All of its shades are not even listed.
How much beauty lies within sea depths. Small fish swim in flocks among green and yellowish algae. And the sandy bottom is covered with shells, as if precious stones. I love collecting shells. I like to imagine that I am finding lost treasures from sunken ships. And how many such treasures are still fraught with the depths of the sea?
There is nothing better than spending a day at sea. You can have fun and swim with family and friends. And sometimes you just want to walk alone, feel the peace under the sound of the waves.
Question 1. How many oceans are there on Earth? Name and show them on the map of the hemispheres. Which ocean is the largest; the smallest?
It is generally accepted that on the globe four oceans: Pacific, Atlantic, Indian and Arctic. But in 2000, the International Hydrographic Organization decided to separate from the Atlantic, Indian and Pacific the fifth ocean surrounding Antarctica - the Southern (or Antarctic) Ocean. The largest of the oceans is the Pacific. Its area is 178.7 million km2. The smallest, the Arctic Ocean, covers an area of approximately 14.75 million km2.
Question 2. Using the maps of the atlas, determine whether the seas are inland or marginal: a) Red; b) Kara; c) Arabian; d) Baltic; e) Okhotsk. What oceans are these seas part of?
Inland seas: Red, Baltic.
Marginal seas: Kara, Arabian, Okhotsk.
The Red and Arabian Seas are part of indian ocean, Kara and Baltic are parts of the Arctic Ocean, and the Okhotsk is part of the Pacific Ocean.
Question 3: Take an imaginary journey from New York to Tokyo. How many itineraries for such a journey can you name? Through what seas, oceans, canals, bays and straits do these routes pass?
Two main routes through east and west. By plane across the Pacific Ocean. across the atlantic ocean, Gulf of Mexico, Panama Canal, Pacific Ocean, Sea of Japan.
Question 4. What is the difference between: a) the island and the mainland; b) the bay and the sea?
a) The island is surrounded by water on all sides, the mainland too, but the continents have large area, i.e., they differ in size.
b) A bay is a part of the sea that protrudes into the land, and the sea is part of the ocean, the sea can be located without going into the land, that is, they differ in size and location.
Question 5. Using the description plan geographical location seas in the appendices, describe the position of the Bering and Black seas.
Bering Sea - a sea in the north of the Pacific Ocean, separated from it by the Aleutian and Commander Islands; The Bering Strait connects it with the Chukchi Sea and the North Arctic Ocean. The Bering Sea washes the shores of Russia and the United States.
The length of the sea from north to south is 1,600 km, from east to west - 2,400 km.
Black Sea - inland sea of the basin Atlantic Ocean. The Bosphorus connects with the Sea of Marmara, further, through the Dardanelles.
The greatest length of the sea from north to south is 580 km. The greatest depth is 2210 m, the average is 1240 m.
Question 6. What does the salinity of 18%o mean? What is the salinity of sea water if 1 liter of this water contains 11 g of minerals?
Salinity 18 ‰ (ppm - thousandth of a number), i.e., one liter of water contains 18 g of salt.
If in 1l. of this water contains 11g. various substances, then the salinity of the water is 11‰ (ppm).
Question 7. What are the reasons that affect salinity ocean water. Locate the Yellow Sea and the Sea of Japan on the ocean map. Which one will have the lowest salinity? Why?
The salinity of the waters of the World Ocean varies depending on external conditions. For example, major rivers or melting ice desalinates the water, and in conditions of low rainfall and high evaporation, salinity increases.
Yellow Sea - average salinity 11%, in the Sea of Japan - from 33.7 to 34.3%. Salinity is lower in the Yellow Sea. The salinity of the yellow sea is lower because large rivers flow into it, which desalinate it.
The Dead Sea
Dead Sea ("Sea of Salt"; also Asphalt Sea, Sodom Sea) - endorheic salt Lake between Israel and Jordan. The water level in the Dead Sea is 430 m below sea level and is falling at a rate of approximately 1 m per year. The coast of the lake is the lowest piece of land on Earth. The Dead Sea is one of the most saline bodies of water on Earth, salinity is 300-310 ‰, in some years up to 350 ‰. The length of the sea is 67 km, the width is 18 km at its widest point, maximum depth 306 m.
The Jordan Valley, in which the Dead Sea lies, is a unique geological formation. It was through its territory that a fault passed earth's crust and formed two continents - Eurasia and Africa. The territory of the valley is an active part of the Syrian-African mountain fault, which should lead to a complete separation of the continents. True, this will happen in a few million years. Earthquakes often occur here, sometimes very strong.
Modern borders The Dead Sea was formed relatively recently - 20-40 thousand years ago due to the replenishment of the basin basin with the waters of numerous rivers, streams and the Jordan River. The salinity level of its water is constantly growing, since there are no sources near the sea, and the evaporation of water from the surface is very active due to the hot climate of these places. Salt, on the other hand, remains in the sea and its quantity is constantly increasing, since the consumption of water for evaporation exceeds the income from fresh springs.
The sea is slowly dying and soon, indeed, will become Dead. Only in the last 100 years coastline went 40 meters down. Scientists believe that living Dead Sea there are no more than 700-800 years left.
Long dead time the sea was considered completely lifeless. However, the nature of the planet knows many facts of the incredible adaptability of life in the most extreme conditions.
The same can be said about the Dead Sea. In its water, scientists have discovered the smallest living organisms, which are single-celled creatures. In my own way biological structure they are similar to bacteria, but have a different molecular composition. These microbes can live where no one else can survive. In addition to microbes, waters of the Dead the seas took root special fungi. Well, when the season of prolonged rains comes, flagellate algae, related to chlorella, rapidly begin to develop.
Since ancient times people have known about unique properties Dead Sea and its locations. Here is quite unusual. solar radiation, the composition of the sea water, rich in various minerals and healing substances, thermal mineral springs and streams, therapeutic mud and an atmosphere enriched with oxygen. All this gives reason to call the Dead Sea healing place on the planet. Diseases such as psoriasis, eczema, arthritis and many others are treated here. dangerous diseases.
For those who would like to get rid of similar ailments, I give a reference to one of the resources offering treatment in Israel.
