Ocean currents. World ocean All currents on the world map on the contour
NASA specialists have created a new map of the world's ocean currents. Its difference from all previous ones is interactivity - anyone can independently look at all the stable water flows and determine the temperature nature of the flow.
Did you know that ocean water is heterogeneous? It is logical that closer to the surface it is warmer than at depth. However, not everyone knows that the volume of salt in ocean water, with rare exceptions, is inversely proportional to the depth at which this water is located - the deeper, the fresher it is. However, there are exceptions to this rule. For example, in the Arctic and Antarctic, deep waters are also saturated with salt - ice layers that penetrate to great depths contain particles of surface salt evaporation, enriching the entire water layer with them.
The top layer of ocean water is driven by stable air currents. Thus, the map of ocean currents is generally identical to the map of sea winds.
Unique online map
A unique map with which you can examine in detail the currents of all the oceans of the world
The model was developed to demonstrate the mechanism of thermal circulation in the world's waters. However, the map is not absolutely accurate - in order to better demonstrate the difference between surface and deep water flows, in certain areas the depth indicator is somewhat overestimated in relation to the real one.
The animation component of the new map was modeled by NASA scientists at the Goddard Space Flight Center laboratory.
Comparative current contour map
Below is a classic contour map of the world's ocean currents in Russian, which schematically displays all the main cold and warm currents of the world's oceans. The arrows indicate the direction of movement, and the color indicates the temperature characteristics of the water - whether a particular current is warm or cold.
Conventional signs There are contour, linear and non-scale.
- Contour(area) signs lakes are shown, for example;
- Linear signs - rivers, roads, canals.
- Off-scale signs For example, wells and springs are marked on plans, and settlements, volcanoes, and waterfalls are marked on geographic maps.
Rice. 1. Examples of off-scale, linear and areal symbols
Rice. Basic symbols
Rice. Conventional signs of the area
Isolines
There is a separate category of symbols - isolines, i.e. lines connecting points with the same values of the depicted phenomena (Fig. 2). Lines of equal atmospheric pressure are called isobars, lines of equal air temperature - isotherms, lines of equal heights of the earth's surface - isohypses or horizontals.
Rice. 2. Examples of isolines
Mapping methods
To depict geographical phenomena on maps, various ways .By way of habitats show areas of distribution of natural or social phenomena, for example animals, plants, and some minerals. Traffic signs used to show sea currents, winds, and traffic flows. High-quality background show, for example, states on a political map, and quantitative background - division of a territory according to any quantitative indicator (Fig. 3).
Rice. 3. Cartographic methods: a - method of areas; b - traffic signs; c - method of high-quality background; d - quantitative background - dotted signs
To show the average magnitude of a phenomenon in any territory, it is most advisable to use the principle of equal intervals. One way to get the interval is to divide the difference between the largest and smallest indicator by five. For example, if the largest indicator is 100, the smallest is 25, the difference between them is 75, its 1/5 is -15, then the intervals will be: 25-40, 40-55, 55-70, 70-85 and 85-100 . When showing these intervals on a map, a lighter background or sparse shading depicts less intensity of the phenomenon, darker tones and dense shading depict greater intensity. This method of cartographic representation is called cartogram(Fig. 4).
Rice. 4. Examples of cartograms and map diagrams
To the method map diagrams are used to show the total magnitude of a phenomenon in a particular territory, for example, electricity production, the number of school students, fresh water reserves, the degree of arable land, etc. Map diagram called a simplified map that does not have a degree network.
Relief depiction on plans and maps
On maps and plans, the relief is shown using contour lines and elevation marks.
Horizontals, as you already know, these are lines on a plan or map connecting points on the earth’s surface that have the same height above the ocean level (absolute height) or above the level taken as a reference point (relative height).
Rice. 5. Image of the relief with horizontal lines
In order to depict a hill on a plan, you need to define it relative height, which shows how vertically one point on the earth’s surface is higher than another (Fig. 7).
Rice. 6. Image of a hill on a plane
Rice. 7. Determination of relative height
The relative height can be determined using a level. Level(from fr. niveau- level, level) - a device for determining the difference in height between several points. The device, usually mounted on a tripod, is equipped with a telescope adapted for rotation in a horizontal plane and a sensitive level.
Conduct hill leveling - this means taking measurements of its western, southern, eastern and northern slopes from the bottom to the top using a level and driving in pegs in the places where the level was installed (Fig. 8). Thus, four pegs will be driven in at the bottom of the hill, four at a height of 1 m from the ground if the height of the level is 1 m, etc. The last peg is driven in at the top of the hill. After this, the position of all the pegs is plotted on the area plan and a smooth line connects first all points that have a relative height of 1 m, then 2 m, etc.
Rice. 8. Leveling a hill
Please note: if the slope is steep, the horizontal lines on the plan will be located close to each other, but if it is gentle, they will be far from each other.
Small lines drawn perpendicular to the horizontal lines are berg strokes. They show in which direction the slope goes down.
Horizontal lines on the plans depict not only hills, but also depressions. In this case, the berg strokes are turned inward (Fig. 9).
Rice. 9. Depiction of various relief forms by horizontal lines
Steep slopes of cliffs or ravines are indicated on maps by small teeth.
The height of a point above mean ocean level is called absolute height. In Russia, all absolute heights are calculated from the level of the Baltic Sea. Thus, the territory of St. Petersburg is located above the water level in the Baltic Sea by an average of 3 m, the territory of Moscow - by 120 m, and the city of Astrakhan is below this level by 26 m. Elevation marks on geographical maps indicate the absolute height of the points.
On a physical map, the relief is depicted using layer-by-layer coloring, that is, with colors of different intensities. For example, areas with a height from 0 to 200 m are painted green. At the bottom of the map there is a table from which you can see which color corresponds to which height. This table is called height scale.
Parts of the World Ocean.
1. Draw a route for a trip around the world on a contour map of the hemispheres so that it passes through all the oceans. Label the seas, bays, straits through which your route is laid.
2. Find the boundaries of all oceans on the map of the oceans in the atlas. Put them on a contour map. Mark the boundary of the Southern Ocean identified by some scientists.
3. Name an ocean whose borders are all southern
Arctic.
4. Using a map of the hemispheres and a map of the oceans, write a description of one of the oceans.
5. Using a map of the hemispheres, write a description of the Mediterranean Sea.
6. In Figure 12, use numbers to indicate: 1 - coastline, 2 - bays, 3 - straits, 4 - islands, 5 - peninsulas.
7. In Figure 13, indicate:
a) peninsulas: Arabian, Scandinavian, Labrador, Somalia, Hindustan;
b) islands: Greenland, Madagascar, Hawaiian, Great Barrier Reef, New Guinea;
c) bays: Bengal, Mexican, Guinea;
d) Straits: Bering, Gibraltar, Magellan, Drake;
e) seas: Black, Baltic, Barents, Mediterranean, Red, Okhotsk, Japanese, Caribbean.
Some properties of ocean water.
1*. Which sea has more salinity - the Arabian or the Okhotsk? Why?
Arabian. More rivers flow into the Sea of Okhotsk, and there is more precipitation there. Arabian has more evaporation.
2. Using the physical map of Russia, determine:
a) completely frozen seas: Kara, Laptev, East Siberian.
b) partially frozen seas: Baltic, Barentsevo.
c) ice-free seas: Black, Caspian, Japanese.
3. Using the map of the oceans in the atlas, set:
a) seas with the highest surface water temperatures - Japanese, South Chinese, Arabian, Caribbean, Red;
b) seas with the lowest surface temperatures - Greenland, Barents, Kara, Laptev, East Siberian.
Waves in the ocean.
After studying § 26 of the textbook and reading task 3 after it, fill out the table.
Ocean currents.
1. Using the map of the oceans in the atlas, mark five warm and five cold currents in Figure 14. Sign their names.
2*. Why do both warm and cold currents occur at the same latitude?
Because the wind drives away warm surface waters, and colder ones rise in their place.
Study of the World Ocean.
Based on the text of the textbook, make a plan for the story “How they studied and are studying the ocean.”
1. What happens on the surface of the ocean and in coastal waters.
2. Jacques Cousteau
3. Explorers of great depths.
4. Special research vessels.
Sea currents are constant or periodic flows in the thickness of the world's oceans and seas. There are constant, periodic and irregular flows; surface and underwater, warm and cold currents. Depending on the cause of the flow, wind and density currents are distinguished.
The direction of currents is influenced by the force of the Earth's rotation: in the Northern Hemisphere, currents move to the right, in the Southern Hemisphere, to the left.
A current is called warm if its temperature is warmer than the temperature of the surrounding waters; otherwise, the current is called cold.Density currents are caused by pressure differences, which are caused by the uneven distribution of seawater density. Density currents are formed in the deep layers of seas and oceans. A striking example of density currents is the warm Gulf Stream.
Wind currents are formed under the influence of winds, as a result of the frictional forces of water and air, turbulent viscosity, pressure gradient, deflecting force of the Earth's rotation and some other factors. Wind currents are always surface currents: northern and southern trade winds, the current of the western winds, the inter-trade winds of the Pacific and Atlantic.
1) The Gulf Stream is a warm sea current in the Atlantic Ocean. In a broad sense, the Gulf Stream is a system of warm currents in the North Atlantic Ocean from Florida to the Scandinavian Peninsula, Spitsbergen, the Barents Sea and the Arctic Ocean.
Thanks to the Gulf Stream, the countries of Europe adjacent to the Atlantic Ocean have a milder climate than other regions at the same latitude: masses of warm water heat the air above them, which is carried by westerly winds to Europe. Deviations of air temperature from the average latitude values in January reach 15-20 °C in Norway, and more than 11 °C in Murmansk.2) The Peruvian Current is a cold surface current in the Pacific Ocean. It moves from south to north between 4° and 45° south latitude along the western coasts of Peru and Chile.
3) The Canary Current is a cold and, subsequently, moderately warm sea current in the northeastern part of the Atlantic Ocean. Directed from north to south along the Iberian Peninsula and North-West Africa as a branch of the North Atlantic Current.
4) The Labrador Current is a cold sea current in the Atlantic Ocean, flowing between the coast of Canada and Greenland and rushing south from the Baffin Sea to the Newfoundland Bank. There it meets the Gulf Stream.
5) The North Atlantic Current is a powerful warm ocean current that is the northeastern continuation of the Gulf Stream. Starts at the Great Bank of Newfoundland. West of Ireland the current divides into two parts. One branch (the Canary Current) goes south and the other goes north along the coast of northwestern Europe. The current is believed to have a significant influence on the climate in Europe.
6) The Cold California Current emerges from the North Pacific Current, moves along the coast of California from northwest to southeast, and merges in the south with the North Trade Wind Current.
7) Kuroshio, sometimes the Japan Current, is a warm current off the southern and eastern coasts of Japan in the Pacific Ocean.
8) The Kuril Current or Oyashio is a cold current in the northwest Pacific Ocean, which originates in the waters of the Arctic Ocean. In the south, near the Japanese Islands, it merges with Kuroshio. It flows along Kamchatka, the Kuril Islands and the Japanese islands.
9) The North Pacific Current is a warm ocean current in the North Pacific Ocean. It is formed as a result of the merger of the Kuril Current and the Kuroshio Current. Moving from the Japanese islands to the shores of North America.
10) The Brazil Current is a warm current of the Atlantic Ocean off the eastern coast of South America, directed to the southwest.
P.S. To understand where the different currents are, study a set of maps. It will also be useful to read this article
The Atlantic Ocean, or Atlantic, is the second largest (after the Pacific) and the most developed among other water areas. In the east it is limited by the coasts of South and North America, in the west - Africa and Europe, in the north - Greenland, in the south it merges with the Southern Ocean.
Distinctive features of the Atlantic: a small number of islands, complex bottom topography and a highly indented coastline.
Characteristics of the ocean
Area: 91.66 million sq. km, with 16% of the territory falling on seas and bays.
Volume: 329.66 million sq. km
Salinity: 35‰.
Depth: average - 3736 m, greatest - 8742 m (Puerto Rico Trench).
Temperature: in the very south and north - about 0°C, at the equator - 26-28°C.
Currents: conventionally there are 2 gyres - Northern (currents move clockwise) and Southern (counterclockwise). The gyres are separated by the Equatorial Intertrade Current.
Main currents of the Atlantic Ocean
Warm:
Northern trade wind - begins off the west coast of Africa, crosses the ocean from east to west and meets the Gulf Stream near Cuba.
Gulf Stream- the most powerful current in the world, which carries 140 million cubic meters of water per second (for comparison: all the rivers of the world carry only 1 million cubic meters of water per second). It originates near the coast of the Bahamas, where the Florida and Antilles currents meet. Having united, they give rise to the Gulf Stream, which flows into the Atlantic Ocean through the strait between Cuba and the Florida Peninsula. The current then moves north along the US coast. Approximately off the coast of North Carolina, the Gulf Stream turns east and enters the open ocean. After approximately 1,500 km, it meets the cold Labrador Current, which slightly changes the course of the Gulf Stream and carries it to the northeast. Closer to Europe, the current splits into two branches: Azores and North Atlantic.
Only recently it became known that 2 km below the Gulf Stream there is a reverse current flowing from Greenland to the Sargasso Sea. This flow of icy water was called the Anti-Gulf Stream.
North Atlantic- a continuation of the Gulf Stream, which washes the western coast of Europe and brings the warmth of southern latitudes, providing a mild and warm climate.
Antilles- begins east of the island of Puerto Rico, flows north and joins the Gulf Stream near the Bahamas. Speed - 1-1.9 km/h, water temperature 25-28°C.
Interpass countercurrent - current that encircles the globe at the equator. In the Atlantic, it separates the North Trade Wind and South Trade Wind Currents.
South Passat (or South Equatorial) - passes through the southern tropics. The average water temperature is 30°C. When the South Trade Wind Current reaches the coast of South America, it divides into two branches: Caribbean, or Guiana (flows north to the coast of Mexico) and Brazilian— moving south along the coast of Brazil.
Guinean - located in the Gulf of Guinea. It flows from west to east and then turns south. Together with the Angolan and South Equatorial currents, it forms the cyclic current of the Gulf of Guinea.
Cold:
Lomonosov countercurrent - discovered by a Soviet expedition in 1959. It originates off the coast of Brazil and moves north. The 200 km wide stream crosses the equator and flows into the Gulf of Guinea.
Canary- flows from north to south, towards the equator along the coast of Africa. This wide stream (up to 1 thousand km) near Madeira and the Canary Islands meets the Azores and Portuguese currents. Approximately around 15°N latitude. joins the Equatorial Countercurrent.
Labrador - begins in the strait between Canada and Greenland. It flows south to the Newfoundland Bank, where it meets the Gulf Stream. The waters of the current carry cold from the Arctic Ocean, and along with the flow, huge icebergs are carried south. In particular, the iceberg that destroyed the famous Titanic was brought precisely by the Labrador Current.
Benguela- is born near the Cape of Good Hope and moves along the coast of Africa to the north.
Falkland (or Malvinas) branches off from the West Wind Current and flows north along the east coast of South America to the Gulf of La Plata. Temperature: 4-15°C.
Current of the westerly winds encircles the globe in the region of 40-50°S. The flow moves from west to east. In the Atlantic it branches off South Atlantic flow.
Underwater world of the Atlantic Ocean
The underwater world of the Atlantic is poorer in diversity than in the Pacific Ocean. This is due to the fact that the Atlantic Ocean was more exposed to freezing during the Ice Age. But the Atlantic is richer in the number of individuals of each species.
The flora and fauna of the underwater world is clearly distributed among climatic zones.
The flora is represented mainly by algae and flowering plants (Zostera, Poseidonia, Fucus). In northern latitudes, kelp predominates; in temperate latitudes, red algae predominates. Throughout the ocean, phytoplankton actively thrives at depths of up to 100 m.
The fauna is rich in species. Almost all species and classes of marine animals live in the Atlantic. Of the commercial fish, herring, sardine, and flounder are especially valued. There is an active catch of crustaceans and mollusks, and whaling is limited.
The tropical zone of the Atlantic amazes with its abundance. There are a lot of corals and many amazing species of animals: turtles, flying fish, several dozen species of sharks.
The name of the ocean first appears in the works of Herodotus (5th century BC), who calls it the Sea of Atlantis. And in the 1st century AD. The Roman scientist Pliny the Elder writes about a vast expanse of water called Oceanus Atlanticus. But the official name “Atlantic Ocean” was established only in the 17th century.
The history of Atlantic exploration can be divided into 4 stages:
1. From antiquity to the 15th century. The first documents that talk about the ocean date back to the 1st millennium BC. The ancient Phoenicians, Egyptians, Cretans and Greeks knew the coastal zones of the water area well. Maps of those times have been preserved with detailed depth measurements and indications of currents.
2. The time of the Great Geographical Discoveries (XV-XVII centuries). The development of the Atlantic continues, the ocean becomes one of the main trade routes. In 1498, Vasco de Gama, having circumnavigated Africa, paved the way to India. 1493-1501 - Columbus's three voyages to America. The Bermuda anomaly was identified, many currents were discovered, detailed maps of depths, coastal zones, temperatures, and bottom topography were compiled.
Expeditions of Franklin in 1770, I. Kruzenshtern and Yu. Lisyansky of 1804-06.
3. XIX - first half of the XX century - the beginning of scientific oceanographic research. Chemistry, physics, biology, ocean geology are studied. A map of currents has been compiled, and research is being carried out to lay an underwater cable between Europe and America.
4. 1950s - present day. A comprehensive study of all components of oceanography is being carried out. Priorities include: studying the climate of different zones, identifying global atmospheric problems, ecology, mining, ensuring ship traffic, and seafood production.
In the center of the Belize Barrier Reef there is a unique underwater cave - the Great Blue Hole. Its depth is 120 meters, and at the very bottom there is a whole gallery of smaller caves connected by tunnels.
The Atlantic is home to the only sea in the world without shores - the Sargasso. Its boundaries are formed by ocean currents.
Here is one of the most mysterious places on the planet: the Bermuda Triangle. The Atlantic Ocean is also home to another myth (or reality?) - the continent of Atlantis.
