What are the main ice ages of the country's history?
Earth has experienced at least five big ice ages in its history of 4.57 billion years: Huron's attacked (2.4 to 2.1 billion years ago), Sturtian/Marinoan suspension (710 to 640 mya), adgens issing (40 ISSING IS AWARGED (40 ISSING. At the Ice Age (40 years), which is 40 years old), which is currently at an icy age), which is currently on the ice age (40 years), which is 450 to 430 to 430 MyA), 40 to 430 to 430 to icy age), 460 to 430 to the ice age (40 to 430 to 260). Mya). The definition of the Ice Age is a long -term decrease in global temperatures from the historical standard, accompanied by the extension of continental ice plates. Each ice age is cyclical, usually on time sections of 44,000 and 110,000 years, during which ice LED rhythmically expands and retreats.
The exact causes of the historic ice age are unknown but probably appeared because of the differentFactors, including: continents, atmospheric composition (greenhouse gases), variants in solar performance (reflectance) and AST and at and at and at and at and at and at and at and ateroid effects. When the correct variables are introduced, the ice age begins and as soon as it starts, positive feedback effects enter the game. The strongest is simply that the ice is more reflecting than the soil or forest, so large areas covered with ice plates reflect sun rays, causing further temperature drop and increased aperture.
Most of the time is not the ground at the time of the ice and the average global temperature is about 22 ° C (71 ° F). Ice leaves are almost completely absent, only at high altitudes (alpine glaciers). The Poles are cold, but are not covered with ice and the forests reach from pole to pole. Dinosaurs fossils were found in less than 10 ° latitude from the ancient South Pole. Only over about 15% of the country's history occurred.
The two most famous ice ages are probably Sturtian/Marinoan and the last ice age. Thesturtian/Marinoan Glaciation was so serious that evidence of continental glaciers was found around the equator since that period. The average global temperature could drop less than -30 ° C (-22 ° F), cooler than contemporary Antarctica. Some scientists even believe that the oceans have stiffen from top to bottom during this time, resulting in the scenario "Snowball Earth". Life would survive in refugia, such as hydrothermal holes for the deep sea.
The last Ice Age is known because we humans had all our history in it. We think ice leaves covering Greenland and Antarctica are typical even if they are not. More than about 10,000 years ago, there was a serious glacial period that covered the continents in the glaciers to the south as Chicago and Paris. During this period, people had to avoid colonization of Europe or North Asia becauseThese areas were frozen firm. For this reason, human fossils preceding the last glacier period are found only by Vafrica, the Middle East, China, Southeast Asia, Australia and only small parts of Europe, such as Spain and Southern France.