地震(英语课件).ppt

Guide Some knowledge about earthquakes. The damage of earthquakes. The parts of seismic in the world. What is the earthquake? The types of earthquakes. Tectonic earthquake (构造地震) Volcanic earthquake (火山地震) Collapse earthquake（塌陷地震） ?Induced earthquake（诱发地震） Artificial earthquake （人工地震） 制作人员 组长：房小玮 组员：侯正平 关振江 陈晨 陈武阳 赵剑 * Earthquake is the rapid vibration(震动) of the Earth‘s surface. It’s just like wind, rain, lightning, landslide. It’s a natural phenomenon（自然现象）that often occurs on the earth. It originats(发源) from the ground floor of a point, which is named focus(震源). ? The earthquake that is caused by the rupture（破裂）since underground rock dislocation（岩层错动） of the depth (深处) is known as tectonic earthquake. Such earthquake occurs most often, Because of the biggest damage, the earthquake accounts for（占据） about 90 percent of the world over. The earthquake that is caused by the volcano(火山活动)is known as the volcanic earthquake. Volcanic activity may occurs before the volcanic earthquakes, such earthquake around the world accounts for only about 7 percent of the world over. The earthquake that is caused by collapse of the top of underground caves or mines is known as the collapse earthquake. Such relatively small-scale（相对较小的） earthquakes often occur in the limestone caves（溶洞） over the region（地区） or large-scale（大规模） underground mining of the mining area. the earthquake that is caused by the water or oil field activities such as water flooding is known as the Induced earthquake. Such earthquake is only in certain oil reservoir areas or regions. Underground nuclear explosions（核爆炸）, explosives blasting（炸药爆破） and other human-induced ground vibration（振动) is known as the artificial earthquake. Artificial earthquake is caused by human activities such as industrial（工业的） blasting. The vibration that is caused by nuclear explosions in deep water or other parts on the earth sometimes induces earthquake. When a earthquake occurs, th