地震时如何产生的,写一篇英文作文
地震时如何产生的,写一篇英文作文
原文:地震是指岩石圈在内力作用下脱然发生破裂,地球内能以地震波的形式强烈释放出来,从而引起一定范围内地面震动的现象.
发生地震的原因很多,根据地震的成因,可以把地震分为以下几种:
1.构造地震
由于地下深处岩层错动、破裂所造成的地震称为构造地震.这类地震发生的次数最多,破坏力也最大,约占全世界地震的90%以上.
2.火山地震
由于火山作用,如岩浆活动等引起的地震称为火山地震.只有在火山活动区才可能发生火山地震,这类地震只占全世界地震的7%左右.
3.塌陷地震
由于地下岩洞或矿井顶部塌陷而引起的地震称为塌陷地震.这类地震的规模比较小,次数也很少,即使有,也往往发生在溶洞密布的石灰岩地区或大规模地下开采的矿区.
4.诱发地震
由于水库蓄水、油田注水等活动而引发的地震称为诱发地震.这类地震仅仅在某些特定的水库库区或油田地区发生.
5.人工地震
地下核爆炸、炸药爆破等人为引起的地面振动称为人工地震. 人工地震是由人为活动引起的地震.如工业爆破、地下核爆炸造成的振动;在深井中进行高压注水以及大水库蓄水后增加了地壳的压力,有时也会诱发地震.
地震发生时,最基本的现象是地面的连续振动,主要是明显的晃动.在震区的人在感到大的晃动之前,有时首先感到上下跳动.这是因为地震波从地下向地面传来,纵波首先到达的缘故.横波接着产生大振幅的水平方向的晃动,是造成地震灾害的主要原因.
地震对自然界景观产生很大影响,最主要的后果是地面出现断层和地裂缝.大地震的地表断层常绵延几十至几百千米,往往具有较明显的垂直错距和水平错距,能反映出震源处的构造变动特征.但并不是所有的地表断裂都直接与震源的运动相联系,它们也可能是由于地震波造成的次生影响.特别是地表沉积层较厚的地区,坡地边缘、河岸和道路两旁常出现地裂缝,这往往是由于地形因素,在一侧没有依托的条件下晃动使表土松垮和崩裂.地震的晃动使表土下沉,浅层的地下水受挤压会沿地裂缝上升至地表,形成喷沙冒水现象.大地震能使局部地形改观,或隆起,或沉降.使城乡道路坼裂、铁轨扭曲、桥梁折断.在现代化城市中,由于地下管道破裂和电缆被切断造成停水、停电和通讯受阻.煤气、有毒气体和放射性物质泄漏可导致火灾和毒物、放射性污染等次生灾害.在山区,地震还能引起山崩和滑坡,常造成掩埋村镇的惨剧.崩塌的山石堵塞江河,在上游形成地震湖.
英语翻译:
Earthquake refers to the lithosphere in internal force descend from natural fracture, the earth in the form of seismic waves can strongly released, resulting in a certain range ground vibration phenomenon.
The earthquake many reasons, according to the genesis of earthquakes, can put divided into the following several earthquake:
1. Structural earthquake
Due to the deep underground strata rupture, by the collapse of the earthquake as structural earthquake. This kind of earthquake the most times, damaging the largest, accounts for about more than 90 percent of the world earthquake.
Volcanic earthquake 2.
Due to volcanic action, like the magma activity caused earthquake known as the volcano earthquake. Only in volcanic area can occur volcanic earthquake, this kind of earthquake accounts for only 7% of the world earthquake.
Earthquake collapse 3.
Due to the underground caves or mines top subsidence caused by the earthquake known as the collapse of earthquake. This kind of earthquake relatively small size, number are also few, although have, also often occur in cave cloudy limestone region or large-scale underground mining of mining area.
Induce earthquake 4.
Because of the initial impoundment of the reservoir and activities such as injection water caused by earthquake known as the induced earthquake. This kind of earthquake only in certain reservoir or oilfield area happen.
Artificial earthquake 5.
Underground nuclear explosion, explosives are caused by artificial ground vibration called artificial earthquake. Artificial earthquake is caused by human activities of earthquake. Such as industrial, underground nuclear explosion caused by blasting vibration, In deep water in high pressure and large reservoir impounding increased crustal stress, sometimes also can induce earthquake.
When an earthquake occurs, the most basic phenomenon is the ground of continuous vibration, mainly is obvious shaking. In the quake area people feel great shaking before, sometimes first feel about beats. This is because seismic waves from underground to ground came that p-wave first reach's sake. S-wave then produce the large amplitude of the horizontal wobble, is the main cause of the earthquake disaster.
The earthquake on nature landscape impact, the main consequence is ground faulting and ground fissure. Earthquake ground fault often to several hundred kilometers stretching dozens, often have the obvious vertical and horizontal distance from the fault fault, can reflect source in the tectonic change characteristics. But not all surface rupture directly with focal the movements of link, they can also be caused by seismic waves cause secondary influence. Especially surface sediments thicker areas, sloping edge, rivers and both sides the path, which often appear ground fissures are often the result of terrain factors, on the side without relying on shaking that under the condition of surface baggy and split. Earthquake jolts make elongate-shaped sinking, shallow groundwater suffers extruding will rise to the surface along the ground fissures, forming sandblasting take water phenomenon. Large earthquakes can make local terrain change, or uplift, or settlement. Make urban and rural road bran, rails distortion, bridge broken. In modern city, as underground pipes burst and cable was cut off water, power and communications caused by. Gas, toxic gases and radiation can cause fire and poisons, radioactive pollution and so on secondary disasters. In the mountains, the earthquake can cause landslides and landslides, often cause bury towns tragedy. Collapse of rocks blocked rivers, formed in upstream quake lake.