字幕列表 影片播放 列印英文字幕 Smart Learning for All Topic: Earthquakes. What causes earthquakes? I, me and myself. You show off. An earthquake is violent shaking of the earth's crust. The earth's crust is a hard outer covering made up of many pieces called tectonic plates. These plates are always moving. However, the motion is very slow. In a year, they move only 2 to 5 cm. My hair grows faster than their movements. Absolutely. Mostly when these tectonic plates move, they brush against each other without causing great damage. However, sometimes they get stuck and cannot easily slide against each other. But the plates still keep pushing, thus creating pressure. Eventually, the pressure builds up so much that one of the plates suddenly moves above the other. They may crash into each other, causing the crust to shake violently, thus creating an earthquake. For more educational videos please visit http://www.SmartLearningforAll.com Also, don't forget to subscribe to our YouTube channel.