2. THE EARTH’S STRUCTURE -The Earth has three layers:
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CORE: - it’s the inner part of the Earth - It’s divides into two parts: a) inner core :- it’s extremely hot - It’s solid due to the pressure. b) outer core: - it’s extremely hot - it’s made up of liquid rocks
2. MANTLE: - It’s the intermediate layer of the Earth. - It surrounds the core - Is temperature is very high and can melt the materials and form MAGMA. - Magma is a hot liquid that can emerged to the surface, then is called LAVA - When magama is pushed up to the surface, it can cause volcanic eruptions. 3. CRUST: - It’s a solid and outer part of the Earth. - It’s the layer whee we live. - There are two parts: a) Continental crust: - under the continents - 30 – 70 kilometres deep. b) Oceanic crust: - under the oceans - 10 kilometres deep
2. THE EARTH ‘S STRUCTURE -
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CONTINENTAL DRIFT AND TECTONIC PLATES CONTINENTAL DRIFT: - It’s a theory that explains how Pangea broke up into different continents that move apart. - According to this theory, modern continents are like pieces of a puzzle that once fit together. TECTONIC PLATES: - The Earth ‘s crust is made up of tectonic`plates. - There are eight major plates and several minor ones. - These plates move continually - Plates have 2 movements: - slide against each other - move apart - Boundaries between tectonic plates are unstable zones. - When pressure increase under the Earth’s surface can cause: 1. Volcanic eruptions 2. Earthquakes