Упр.2 Юнит 2.15 ГДЗ Starlight Баранова 11 класс
2 Read the text and decide if the statements are T (true) or F (false). 1 The mantle is the hottest layer of the planet.
Решение #
Приведем выдержку из задания из учебника Баранова, Дули, Копылова 11 класс, Просвещение:
2 Read the text and decide if the statements are T (true) or F (false).
1 The mantle is the hottest layer of the planet.
2 All the Earthtasks crust Is 45km thick.
3 Earthquakes occur when the plates move apart
4 People do not feel the majority of earthquakes.
5 Some earthquakes are good for the planet.
Standings on solid ground?
Our planet is made up of four main layers. The centre is called the core and is the hottest part of the planet. It is divided into two layers, the liner core and the outer core. Around the core is a layer of liquid rock known as the mantle. The final layer is a thin layer of solid rock known as the crust. It is thin compared to the other parts, but in reality, that still means it is between 10 and 45 kilometres thick! It is not one uniform surface but is broken up into many smaller independent pieces called plates, like a cracked eggshell or a jigsaw.
Powerful aments in the mantle cause the plates to move around constantly. The plates usually move at rate of 1 – 10 cm a year, but this tiny movement has incredible effects where the plates meet. The towering Himalayan mountains were formed by two plates pushing into each other and the fiery volcanoes of Iceland are the result of two plates moving apart. Earthquakes, however, tend to occur at the third kind of boundary – where plates slip alongside each other. This is because two plates never slide past each other smoothly. The rocks catch on each other so that the plates are still pushing. Pressure gradually builds up until the rocks can no longer stand the pressure and they suddenly give way. This movement travels to the surface in waves that shake the ground.
Most earthquakes are so tiny that we don’t even feel them. Small earthquakes are useful because they release the dangerous pressure between the plates. Every few years, however, enough pressure builds up to produce a large earthquake, often with catastrophic results for human life and buildings in the affected area. Afterwards the plates start moving once more until they get stuck again, and so the whole process starts over. Such earthquakes are nature’s reminder that we don’t stand on solid ground.