The relief of the earth's surface

Of course, all are well aware that represent those colors. Blue - it's waters, green - plain and lowland, yellow - the various hills. And where yellow turns to brown, it indicates the highest mountains on our planet. Similarly, the need to understand the symbolism and the blue and green colors. Where the blue caused darker - deeper and where lighter - smaller. Well, and where it goes into the blue, there are very great depths of the planet. Hence, at the bottom of the oceans and seas are - as well as on the land surface - its hills, hollows and valleys. Only they are a relief of the seabed and ocean floor. Likewise, the land surface. It would seem that the plain - a flat, level place. But in fact, and it has a huge number of various small and big hills and depressions. Besides plain crossed by river valleys and deep ravines. These ravines are sometimes steep slopes, covered with low hills. All this creates a truly magnificent scenery in many parts of the world. But there are mountains where the terrain and there are surprising metamorphosis. Breathtaking majestic peaks covered with snow caps, replaced by deep steep gorges. In the mountains you will ever encounter is with the ups, the downs with. They create extremely complex terrain. This here it is, the relief of the land. And as you can see, it is very complex and diverse. It includes a variety of forms - from the giant (continents, oceans) to the smallest. This is the most minor irregularities and complex rock formations. For example, to minor irregularities are any violations of the prevailing topography of individual stones, trickles of rainwater, plant roots. Such a variety of relief was formed over a long time and continues even now. Sometimes time is millions of years here primarily to keep in mind the continents and islands And sometimes the process for as many bystrotechen that does not even consider it or notice saying this, remember mudflows, avalanches, landslides, which can sometimes change the landscape beyond recognition, but What other forces are involved in the formation of landforms? To answer this question we must say that planet Earth is a living organism. Simply has a much larger sizes compared with those living organisms that inhabit its crust, the lower atmosphere with the ozone layer, water, seas and oceans, creatures from the tiniest insects to man, together constitute the outer shell of our planet. In geography, this shell is called the geographic scope or geosphere origin, development, and its existence depends on several significant factors. These factors are: the mass of Earth, the location of Earth in the Solar System (149.5 million km from the Sun), Earth's motion around the Sun (at a speed of 29.76 km / s, which determines the duration of the year) and its rotation around its axis (in 23 hours 56 minutes and 4 seconds); shape of the Earth, which, as we said, represents the geoid, the presence of lunar satellite (mass 735 - 10'7 tons, the average distance from Earth 384,400 km), the age of our planet (estimated at 4, 7 billion years). These factors are very important. They determine the seasons, day and night, the presence on our planet zones and latitudes, and many other important processes. Among these important processes and the formation of landforms. It is in direct relation to the origin of continents and oceans. Many millions of years ago, when Earth had just formed as a planet, it was common land. But this is a shareware. Scientists call it Pangea. Then it split into two parts - Laurasia and Gondwana. Look at the physical map of the hemispheres, and you will see that the shapes of the continents can be arbitrarily connected just like pieces of a broken mirror: Brazil in South America, Antarctica, Africa, Arabia, Indian subcontinent and Australia are the "fragments" of Gondwana. Laurasia is separated into North America and Eurasia. But the process of forming a relief after this is not over. Moreover, he goes all the time. Unnoticed for a man in the depths of the earth is constant movement. Most active in the area is currently bottom of the Atlantic Ocean. It extends about six inches a year, pushing America to the west, and Eurasia to the east. Because of the similar processes in the cortex of the bottom of the Indian Ocean Arabia, the Indian subcontinent and Australia are moving to the northeast at the same rate. These changes occur due to the fact that the composition of the outer part of the earth's surface (crust) is not identical in structure. In most of its surface overlain by sedimentary rocks. These include sand, clay and limestone. A little deeper - granite. Behind him another basalt. Together they make up the crust. Most fat is in the mountains. There she reaches 50 - 80 km. Under the plains of the land crust is thinner. But beneath the waters of the oceans is even smaller, if not entirely absent. Then the ocean floor is composed of heavy rocks that lie beneath the earth's crust and continents. Opening of the compatibility between the continents as a mirror of the fragments by the German geophysicist Alfred Wegener, and was described in his book "The emergence of the oceans and continents in 1912. Wegener argued that the granitic continents and basaltic ocean floor does not form a continuous cover, and how to float like a raft on a viscous molten rock, driven by a force associated with rotation of the Earth. Wegener's theory has caused at the time the big hit. But today we know that he was right. Geological studies using modern instruments have proved that the earth's crust consists of about 20 small and large plates or boards, forms, constantly changing its location on the planet. These itinerant tectonic plates crustal thickness is 60 to 100 km and, as the ice and falling, then rising to float on the surface of a viscous magma. When they "find" one on one, then the layer thickens. Start to grow the mountain. In other places, the layers apart and on the surface favor heavy rock. So once they have formed an ocean basin. And from the youngest mountain ranges are the Pyrenees, the Alps, the Caucasus, Tien Shan, Pamir, Kunlun, the Andes, the Cordillera and some others.