Why does South Africa have a much smaller tropical belt than North Africa? Why does Lake Chad change its shape throughout the year and

The geographic boundaries of the seas are not always land. And the sea itself is sometimes not at all the surface of the water, which we are used to seeing it. The name will not be entirely correct from a geographical point of view, since the “shores” of such seas are limited not by land, but by currents.

... We found ourselves in the region of the Sargasso Sea, a mysterious sea located west of Corvo, one of the Azores. This sea covers an area six times the size of Germany. It is all completely covered with a thick carpet of algae. "Seaweed" in Spanish - "sargassa", hence the name of the sea ...

How so: the sea among the ocean? Miss Kingman asked.

This question has not yet been resolved by the scientists themselves. As they should be aware, the warm current of the Gulf Stream is heading north from the Florida Strait to Spitsbergen. But on the way, this current divides, and one arm returns to the south, reaches the Azores, goes to the western shores of Africa and, finally, having described a semicircle, returns to the Antilles. It turns out a warm ring, in which there is cold, calm water - the Sargasso Sea.

Look at the ocean!

Everyone looked around and were amazed: the surface of the ocean lay motionless in front of them, like a standing pond. Not the slightest wave, movement, splash. The first rays of the sun illuminated this strange, frozen sea, which was like a solid carpet of greenish-pale algae.

Belyaev A., “Island of the Lost Ships”

In fact, there is nothing to add to the words of Alexander Romanovich: in his novel he provided a fairly accurate description of a unique natural formation, which is the Sargasso Sea. “Liquid”, unstable shores, formed by currents, change their shape throughout the year, and the sea area varies within 6-7 million km. Because of the direction of the currents and atmospheric pressure in this section of the Atlantic Ocean, the water is almost stationary, except for the powerful, ascending streams from a 7-kilometer depth, discovered in the 1970s by Soviet oceanographers.

But it is not the absence of “material” shores that attracts researchers here, namely algae and sargassus. Here is the largest cluster of them. It is possible that once the sailors found themselves in a particularly dense area: among experienced sailors, the story quickly becomes overgrown with extraneous details, and as a result, a real legend is obtained. It is possible that Belyaev included one of such legends in his novel: the ship got stuck in a dense Sargasso "mess" and could not get out of there. The crew perished from hunger and thirst, and the ships bound by seaweed were destroyed one by one among the Sargassos. In the "Island of the Lost Ships" this version has found its place (there were many like it): in the center of the Sargasso Sea, the ships captured by its brown-green captivity formed an entire island, on which, by some miracle, the surviving crew members supported their existence ... For the sake of fairness, it should be noted that to this day this version attracts many scientists: at the beginning of the last century, Danish microbiologist E. Winge would describe a case when a ship hit a real Sargasso field - wherever you look, everything around was densely covered with algae, and free water was visible only near the sides of the vessel. During his historic journey, Columbus also encountered the Sargassos: he aptly dubbed this part of the Atlantic "a jar of seaweed."

It is believed that for the first time the name "bank" was given by Portuguese sailors: the underwater part of the algae, due to the presence of air bubbles on it, is very similar to a bunch of one of the grape varieties - "sargasso", hence the second name of the sea, which was very popular in its time - Grape ... The seaweed itself is still called “sea grapes”. A small bush, no more than one and a half meters long, is mostly hidden under the surface of the water, the visible part is only a few leaves that act as a sail. Initially, the roots of the plant cling to the bottom, but, breaking off and following the current or gusts of wind, they get lost in the so-called thalli, which make up the Sargasso Sea. There was another version, according to which floating sargassos are formed "in place", vegetatively; however, over time it was dispelled: being cut off from the bottom, sargassians do not reproduce. One way or another, but within the sea there are up to 11 tons. In the Sargasso Sea, representatives of about 60 species of living creatures and plants coexist calmly with each other. On the scale of the ocean, this is negligible, and even this can soon be lost: not so long ago, among the Sargasso thallus, another "layer" was formed, the fault of which is man. The currents that outline the boundaries of the sea become unwitting accomplices in garbage collection. Everything that enters the Gulf Stream in the west, the Canary Current in the east, the North Atlantic in the north and the North Passat in the south, all the garbage - everything is “concentrated” in the Sargasso Sea. Plastic and other waste has formed a floating layer of debris there.

What's the name of the Great Pacific Garbage Patch? Another option is the Eastern Garbage Continent. Imagine the seventh continent - and out of garbage! It was “predicted” back in 1988, but apart from research, absolutely no action is being taken. This “mainland” is located at about 135 ° -155 ° west longitude and 35 ° -42 ° north latitude. Due to the fact that the center of the North Pacific system of currents is almost stationary, it is there that all the waste that daily falls into this part of the ocean is thrown. About 20% was dropped from ships, the rest from land. According to 2001 data, the mass of plastic waste in this zone slightly exceeded 3.5 million tons, now it is more than 100 million. The area of \u200b\u200bthe "spot" is variable, it varies from 700 thousand to 1.5 million km² and more (from 0, 41% to 0.81% of the total area of \u200b\u200bthe Pacific Ocean). One of the "discoverers" of the water dump said that at first people considered it to be something like an island that you can walk on, but this is not so. The consistency of the “continent” is more like a soup: pieces of plastic and other waste float there at a depth of one to one hundred meters, moreover, presumably about 70% of all accumulated trash sinks to the bottom and lies in the ground. If Belyaev created the "Island of the Lost Ships", then humanity as a whole may well create the Island of Garbage and Waste. This spot cannot be seen from the satellite: most of the anthropogenic emissions are under water, and they can only be distinguished from the board of a ship or while scuba diving, in addition, the smallest particles of plastic are not much larger than small marine life. Ships rarely go here, so everyone pretends that there are no problems as such. In addition, the North Pacific Whirlpool belongs to neutral waters - no one is going to take responsibility for this part of the Ocean. They pay attention to the impending disaster only when the next storm covers the nearest beaches with a thick layer of debris. The concentration of plastic in many places of "garbage" exceeds the concentration of zooplankton seven times! 90% of it is plastic, and only 10% goes to organic waste. I suppose there is no need to talk about what effect this garbage has on the animal world. Birds feed the chicks with plastic, try to get enough of it themselves, turtles also eat it, confusing it with edible. The result is a painful death from poisoning, hunger or strangulation.

Since 2008, research has been organized, samples are taken, laboratories are opened to study the garbage continent. I would be very happy to write that there are regular works on cleaning the ocean and recycling the waste floating there, but, unfortunately, I cannot. So far, the learned world provides only words. A spot in the Sargasso Sea, a “garbage dump” in the Pacific and Indian Oceans, and hundreds and thousands of similar, smaller formations that float in all open waters and ... no one cares about them. Neutral territory.

Lakes Chad is a one of a kind large reservoir located in Central Africa, as well as one of the most significant and famous attractions. The lake is located in the west of the republic, near the lands of Shari. By the way, it is worth noting that these waters are the most ancient sources in Africa today, thanks to which the republic got its current name. Chad is considered one of the most volatile lakes in the entire world. This can be done on the assumption that the lakes are constantly changing their external outlines, then expanding in length, then losing width, then shrinking to unimaginable sizes, then on the contrary - increasing tens of times. The lake has no external drains, the waters are a little salty and not intended for drinking, here people can only have a good beach holiday and take a dip. The maximum depth here is only eleven meters. The territory of the lake today is one of the richest territories of the Chad Republic, because it is here that an unimaginable accumulation of wildlife is collected, which is rarely found in such arid regions. Numerous vegetation grows around the lake, which annually serves as a home and a cozy corner for thousands of various animals and birds. The waters serve the local people today, to a greater extent, as a source of seafood and a territory for fishing. It's no secret that it is here that at least over fifty species of marine life are found.

The Shari River with the Logone tributary carries its bottoms to Lake Chad. Fluctuations in water discharge in the river are very significant. At N'Djamena, near the confluence of the Logone, Shari at the beginning of June has a width of 84 m, while at the flood in November it reaches 600 m.

Shari is considered to be one of the most fishy rivers on earth. The largest fish, called the captain, can reach two meters in length and 80 kg in weight, besides, it is very delicate in taste. According to Nachtigall, the inflow of water through rains and rivers is 100 cubic meters. km, and the loss of water through evaporation is 70 cubic meters. km. Due to the absence of a visible source of water from the lake, while the lake water remains fresh, Nachtigall assumes the existence of an underground channel in the northeast direction to Aegea and Borku. Near the river mouths, the water in the lake is fresh, in the rest it is slightly brackish; the insignificance of mineralization is explained, apparently, by the constant change of water in the lake due to the underground outflow of infiltration waters. In a very rainy season (which happens very rarely), at extraordinarily high levels of the water's edge, a temporary surface runoff of the lake forms in the north-east (along the dry channel of Bahr el-Ghazal). The dark, dirty water of the lake is overgrown in places with dense algae. From July to November, under the influence of rains, the water level gradually rises and the low southwestern coast is widely flooded almost to Cook. Over a considerable area, the lake is very shallow (here you can wade it on horseback); the western part near Ngornu and Maduari is very deep. The maximum depth during the rainy season is 11 meters. The banks are mostly swampy and overgrown with papyrus; to the northeast, the area has the character of a steppe, and only the southern coast is distinguished by rich tropical vegetation.

In the eastern part, the lake is covered with a network of islets (up to 100 in number), of which the groups of Buduma, Karka and Kuri are inhabited (up to 30 thousand people) by people from neighboring tribes (Buduma, Kuri, Kanemba, Kanuri, Bulala and Datsa).

In 2006, a lake with an area of \u200b\u200b23 thousand square kilometers, located on the borders of Nigeria, Niger, Cameroon and the Republic of Chad, decreased 26 times and continues to dry up, which became known thanks to the Earth monitoring carried out by the international system "Disaster Monitoring Constellation". Chad is known to dry up for the seventh time in the last millennium. Scientists - paleontologists have established this from the remains of animals found there.

The region of the upper reaches of the Shari is the most fertile and populated in the country. The population density here reaches 15 people per 1 km 2 (with an average density in the Republic of Chad of 3 people per 1 km 2).

The Republic of Chad is divided into two parts: northern and southern. In the south, there are Negro tribes who speak many languages \u200b\u200band dialects. Some of them profess Christianity, others are faithful to local traditional cults. The population of the south is engaged in agriculture. Fertile soils make it possible to grow here along with food valuable industrial crops for export.

The northern part of Chad is mostly deserts and semi-deserts. There is no fertile land. The population has long been engaged in nomadic cattle breeding.

The water in the lake is darkish due to dense algae. During the rainy season, the maximum depth of Lake Chad can reach up to eleven meters. Most of the shores of the lake are swampy, overgrown with papyrus, only the southern shore of Lake Chad is rich in tropical vegetation. There are small islands in the eastern part of the lake.

It should be noted that natural salt deposits are located in the northeastern part of the Chad coast.

The presented lake is home to unique animals - manatees, crocodiles, and hippos. Also on the territory of this lake, you can see a large number of beautiful marsh and water birds. This lake is home to a wide variety of fish.

The fate of the city of Puchezh is unusual. He had two lives. The first lasted several centuries, the second began in 1952. In connection with the construction of the Gorky hydroelectric power station, Puchezh got into a flood zone, and it was decided to move the city to a new, elevated place. The old city with its churches, merchant buildings, and beautiful embankment disappeared forever. Some of the wooden buildings were moved to the new city, and all the stone ones were destroyed. One church of the Assumption of the Most Holy Theotokos survived, but it also suffered a bitter fate: in the early 1960s, it was dismantled. But the old city lives on in the memory of people, in historical documents. The earliest of the surviving documents mentioning Puchezh is dated 1614, but it contains references to the petitions of the Puchezh headman and kisses from 1604 and 1594, which confirms that in the second half of the 16th century, Puchezh was a significant settlement.

The name of Puchezh was given by the rivers Bolshoy Puchezh (now Pushhavka) and Malyy Puchezh (nowadays Rodinka), at the confluence of which into a small river Pushhavka the Puchezhskaya settlement was located, where residents were engaged in crafts and trade. They were not engaged in arable farming. The earliest information about the Puchezhans and their occupations is in the scribe's book dated 1676. The Puchezhskaya suburb was included in the Order of the Big Palace, i.e. belonged personally to the royal family and paid rent to the royal treasury. There were then 114 residential courtyards in the settlement, in which about 500 people lived. They sold dyes (dyed canvases), leather, salt and soap. Of the crafts, canvas dyeing and blacksmithing were quite significant. In addition to the monetary quitrent, the Puchezhans supplied fish and salt to the royal court.

Near the Puchezhskaya Slobodka, on the other side of the Pushhavka River, there was a men's monastery - Pushhavinskaya Hermitage. It was not large; at different times, from 6 to 20 monks lived in it. In 1717, at the expense of the Metropolitan of Novgorod and Galich Job, a stone church of the Resurrection of Christ was built in the monastery instead of a wooden one. Job donated a lot of valuable utensils and a shroud to the monastery in 1441. In 1918 the shroud was confiscated and is now kept in the funds of the Kremlin museums.

In 1793, by the decree of Empress Catherine II, the Puchezhskaya suburb was transformed into the Puchezh posad. The monastery was closed by that time. Preserved until 1917 a convent - an almshouse at Podgorny parish. In it, in a separate cell at the end of the 18th - beginning of the 19th centuries, the mysterious nun Arcadia lived. In the 2nd half of the 18th - 1st half of the 19th centuries, Puchezh dramatically changed its appearance. The Puchezh merchants began to buy and sell bread and flax, took large caravans of barges to the main grain market of the country - to Rybinsk. ) contracted to transport bread for the Puchezh merchants. Therefore, Puchezh was one of the largest centers for hiring barge haulers. With a population of about 1,000, barge haulers gathered up to 6,000 by the beginning of navigation. By the middle of the 19th century, about 700,000 poods of flax a year were turned over at the Puchezh market. Vyaznikovsky merchant Joseph Senkov built a flax-spinning factory in Puchezh in 1862 with about 1000 workers.

In connection with the reforms in Russia in 1860-1870. Puchezh received elements of self-government. In 1863, a zemstvo was introduced, in 1870 a city council appeared in Puchezh with a city head at its head, and its own coat of arms appeared. According to the data of 1898, the population of the settlement is 2315 people. In the posad there were 6 churches, an elementary school, a higher elementary school, a city public bank, a savings bank. The change of power in 1917 was calmly endured by the Puchezhans; they only held re-elections to the city council, which were won by the Social Revolutionaries. On February 25, 1918, the City Council was established. In 1924, when the population of Puchezh was already 4088 people, a city power plant was built, in 1925 - the first residential buildings for workers, the city of Puchezh received the official status of a city. In 1929, the Puchezhsky district was created, which changed its shape and area many times. In 1947, the fate of Puchezh was decided, and a decision was made to build the Gorky hydroelectric power station.

Now Puchezh with 9 thousand inhabitants does not look like the old one. Multi-storey buildings and new buildings make up the city. Among them - a flax-processing plant, a plant of reinforced concrete structures, a stitching and sewing factories, an enterprise for the repair of agricultural machinery.

Based on materials from the site: http://tourizm.ivanovo.ru
Additional information http://kond-nikolaj.narod.ru/puchezh-histori-01.html

Why does South Africa have a much smaller tropical belt than North Africa? Why does Lake Chad change its shape and area during the year? Why is Antarctica considered the highest continent on Earth?

Answers:

1) North Africa is elongated in a sublatitudinal direction, and South in a submeridional direction, therefore, a feature of Africa's conciguration is the unequal land area to the north and south of the equator. The northern part of the continent is more than twice the width of the southern one: the greatest distances between the extreme eastern and western points of the northern and southern parts of the continent are 7600 and 3100 km, respectively. 2) If it were not for the southern rivers Shari and Komadugu-Yobe, which feed the lake with their waters, it would have disappeared long ago. These tributaries run down from the slopes of the relatively low mountains that separate the catchment of Chad from the basins of the great African rivers Nile and Congo. About 500-600 millimeters of precipitation falls here throughout the year. This amount of moisture is sufficient to feed both rivers and Lake Chad. Competing with the desert, the lake often changes its boundaries, and from this the area of \u200b\u200bthe water surface changes dramatically. 3) Antarctica is covered with an ice shell, the average height of which is 2040 meters (2.8 times the average height of the surface of all other continents). Near the South Pole, the thickness of the ice shell reaches 3800 meters. The total mass of frozen water concentrated in Antarctica is 30 million cubic kilometers. Under its weight, the earth's crust on this continent sagged to 950 meters.

Why does South Africa have a much smaller tropical belt than North Africa? Why does Lake Chad change its shape throughout the year and

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