The seismic wave origin, called the source. Source on the ground of the vertical projection, called the epicenter. The depth of the epicenter to the source called focal depth. Usually focal depth of less than 70 km of the quake is shallow, deep in the 70-300 km is in the earthquake, the depth is GREater than 300 kilometers of deep earthquakes. Devastating earthquake is generally shallow earthquake. Such as the Tangshan earthquake in 1976 the focal depth of 12 km.
引起地球表层振动的原因很多，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、气体爆炸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。
地震波发源的地方，叫作震源。震源在地面上的垂直投影，叫作震中。震中到震源的深度叫作震源深度。通常将震源深度小于70公里的叫浅源地震，深度在70-300公里的叫中源地震，深度大于300公里的叫深源地震。破坏性地震一般是浅源地震。如1976年的唐山地震的震源深度为12公里。
地震避难自救中英文大全
Chun-when the nearest escape, post-earthquake rapid evacuation to a safe place contingency protection is a better way. The so-called nearest escape, according to local conditions and in accordance with the different situations of different countermeasures.
School personnel shock absorbers
In the schools, the earthquake is most in need of school leaders and teachers of calm and resolute. Medium and long-term earthquake prediction is the region, usually to combine teaching and learning activities to students about the earthquake and defense, shock absorbers knowledge. Zhen former students to make good arrangements for the transfer, withdrawal routes and venues; post-earthquake calmly directing the orderly withdrawal of students. In relatively strong, secure housing, can escape the desk, next to the podium, teaching students to the building of the small hall, a pipeline support room, and never allows students to span or jumping from buildings.
Earthquake, shock absorbers in the streets
When the earthquake occurred, high-rise buildings of glass and concrete building lateral fragments, and advertising signs, tinplate board, Nihong Deng-, may fall wounding, walking in the street, will be the best side of the bag or Top soft goods in the head, no item can also be in the head with their hands for as much as possible for self-defense preparations to be calm, should quickly leave the poles and the wall, toward a broader regional escape.
Shop workers shock absorbers
Shop workers can hide in cars, machine tools and equipment under the higher, not to panic span, the special status of workers should be the first closure of inflammable, explosive, toxic gas valves, reduce the time high-temperature, high pressure pipeline temperature and pressure to close operations设备. Most staff can work from the scene, where security protection under the premise of a small number of staff to remain at the scene surveillance danger at any time, the timely processing of the accidents may occur, to prevent the occurrence of secondary disasters.
When the earthquake emergency vehicles travelling on the shock absorber
(1) drivers should slow down as soon as possible, and gradually brake gate;
(2) passengers (especially on trains) Application hands firmly seize the handle, or pillars, such as seats and pay attention to preventing baggage fell from the shelves wounding, facing the direction of traffic, to the seats before the arm靠在Upholstery, Huzhu face, tend to channel the body, two-handed Huzhu head; Beichao directions of traffic of people, two-handed Huzhu after brain and abdominal carrying nursing knee, tightening the body, for defensive posture.
