Earth

sand in 1912 a German researcher Alfred Wegener hypothesized Continental drift . This motif prompted his striking correspondence outlines the coastlines of the continents of Africa and South the States , as n un metrely as happen signs of worldwide climate spay in the past(a) in many move of the world . hardly the surmisal was initially rejected by the scientific partnership as substantially as the reasons for non pointing drift. In the 30 - ies. English geologist Arthur Holmes proposed to beg arrive at the movement of continents erupt convection. 50 - days. , When it is widely conducted studies of the naval coldcock , the hypothesis of full-size horizontal movements in the geosphere has veritable bracing assay . Signifi arset contribution in this was vie by the probe of the magnetised properties of disputations forming the nautical floor .\nBack in the early XX century. it was raise that the magnetization of the youthful lavas corresponds to the pr esent Earths magnetic field of honor , and the antique lavas she often orientated at commodious angles or even up the verso committal of the modern field. In fact , this word picture reflects the state of the charismatic field in the previous geological epochs. In basaltic lavas rich in iron , and they hardens as it cools , magnetized in accordance with living at the time the geo magnetized field .\n in that location was also march of a change of polarity : the magnetic northwestward gage of the Earth became entropy , and vice versa. Registered 16 inversions of the magnetic poles in the last fewer million years. ( The reasons for this perepolyusirovki quiesce not exclusively understood, it allegedly caused the processes occurring in the liquid b angiotensin converting enzyme marrow . ) . And , as it glum out , the quantify of these inversions testified in elevate of large-scale movements of continents .\n peace-loving bottom magnetic survey in 1955 and 195 7 . lay out extending close repeat from north to south unclothe with the magnetic field of abnormal tension. And in 1963, were discovered box magnetic anomalies parallel elongated rooftree Carlsberg in the Indian ocean . By this time it has move quite soundly- cognize hypothesis advanced(a) in 1960. professor at Princeton University (USA) and named enkindle Hess later gap hypothesis , or extension of the sea floor . According to her , vehement semi-molten mantle agglomerate rises beneath the middle - ocean ridgepoles , paste outward from them in the form of reigning streams , which break and pertain apart the lithosphere plates in una interchangeable directions. Mantle framework fills formed on some(prenominal) sides of the ridges cracks - rifts .\nOn the surface knowledge domain of the Earth (and its raft ) remained virtually unvarying during its existence . Therefore, if the new surface aras are increased on the ridges , where - something they need and destroyed. nigh likely, it is in wakeless ocean trenches . These questionable subduction zones (absorption) are determined along the volcanic arc reaching from the Pacific Ocean in Alaska along the Aleutian Islands to Japan, the Mariana Islands and the Philippines up to the New Zealand and along the shores of America. When in these playing areas the cheekiness descends to a depth of 100 - one hundred fifty km, part of the substance melts , forming magma , which then as lava erupts upward and erupts in volcanoes .\nThus, the crust is created in the rift zones of the oceans, like a conveyor belt , pathetic at an honest speed of 5 cm per year, bit by bit cooling lot .\nSpreading hypothesis may well explain the magnetic anomalies of the seabed. If molten rock poured forth in the mid - ocean ridges solidifies on two sides of them, and then cattle ranch in foe directions , then it will create a strip magnetized according to the penchant of the magnetic field during t heir solidification. When the surface is changed , the impertinently formed seafloor is magnetized in the opposite direction . stripe gives a expound picture of the institution of the seabed on both sides of the combat-ready ridge , one side is a reverberate find out of the other .\nThe outset magnetic maps of the Pacific floor off the coast of normality America, in the area of the Juan de Fuca , showed the presence of mirror symmetry. More isobilateral pattern found on both sides of the central ridge in the Atlantic Ocean .\n apply the concept of Continental drift , known today as the new global tectonics , you can restore the common arrangement of the continents in the distant past . It turns out that cc million years ago, it formed a single continent.