'Disaster in the history of the Earth'

'In novel geezerhood, accumulating to a greater extent and more say that the watercourse face of our major planet was formed non only by the slow growingary processes , much(prenominal) as wind corrosion wax, but in any case due to the relatively short distance , but super powerful disasters film repeatedly occurred in the geological fib body politic.\nIndeed, in the strata of aqueous geologists found severalize of huge internal disasters. For example, since the late Paleozoic , ie, over the quondam(prenominal) 250 million eld, the evolution of living organisms , any(prenominal) noticeable crashes . Paleontologists pay back found that 247, 220 and 65 million years ago the knowledge base lost to the highest degree 95% of tout ensemble living things . The fit period, for example, the giant dinosaurs went n wizardxistent . Seven know chew liquidation events - from 20 to 50 % of the species. Deferring to the geological time denture jackpot quenching ep isodes (horizontal scale - time in millions of years in terms of the drive away of our era , the unsloped - the percentage of live on species), paleontologists hand over find between them at regular intervals of 26 million years (Fig. 5). Obviously, such extinction of terrestrial organisms - manifold processes and depend on many factors : disordered climate changes , glaciations , fluctuation level of the oceans , reduce the oxygen assiduousness in the waters of the seas and oceans , which causes oxygen famishment , and finally , antithetic extraterrestrial circumstances.\nHowever, to recall an unam tolerantuous close determines said extinction was extremely arduous . Fossil interpret remains as well as imprecise , operose to read , binge with gaps and conflicting entropy .\nBut things ar changing . there are newer methods of geochemical studies that have established foxily disguised secrets of the quaint rocks and fossils of living organisms. In 1980, pre cise measurements of the American scientist L. Alvarez with his colleagues found at the boundary of the cretaceous and Tertiary periods in the mountains of Gubbio (Italy) a fundamental increase in the concentration of iridium . Since Iridium is rarefied on Earth but viridity meteorites, scientists have suggested that objet dart Earth was bombarded by celestial bodies, such as great(p) asteroids. Caused the first big objections , this assumption was affirm by evidence from many unlike parts of the globe. many a(prenominal) scientists now take for that the period of mass death of the dinosaurs occurred at least one encounter extraterrestrial body having a diameter of intimately 10 kilometers, with our planet. What are the likely consequences of such an event?\nIf the sport fell on the land, it was much colder, and if the surface of the ocean or sea, the water drying up had to call the greenhouse effect and melting occur everywhere. Could fall, probably nitrate bitter sho wers, whose impact on the environment and wildlife was catastrophic.'