Earthquake waves

Advance warning systems and the use of evacuation from areas of danger save lives and should be included in community disaster response plans whenever appropriate. Warnings can now be made months in advance, in the case of El Nino, to seconds in advance of the arrival of earthquake waves at some distance from the earthquake. Computers are being programmed to respond to warnings automatically, shutting down... 

We have learned a great deal about the interior of the earth by studying the earthquake waves which pass through it. 

Earthquake waves tell us that the core is liquid, although this liquid core itself may contain a solid inner core."... 

The transportation of earthquake waves is faster in rocks than in soils. In blasting engineering, there are loose blasting and throwing blasting. 

According to the earthquake record monitored by Chengdu station (CD2) of Chinese National Earthquake Bereau, the Wenchuan earthquake lasted for about 160 seconds and strong part are nearly 20 s. In this paper, earthquake wave of the front 20 seconds is used. Seismosignal software is used to make the filtration with range of 0.1-10 Hz and then do the linear baseline calibration. The velocity time history should be first transferred to velocity-stress time history and then set in the bottom viscous boundary. Stress time history is shown in Figure 7. 

Figure 6. Accelerated velocity curve of earthquake wave.

Geologists and geophysicists have learned enough about earthquakes to be able to identify ways in which the damage they cause can be minimized by appropriate human behavior. In general, there are two main approaches to mitigating the effects of earthquakes Build the structure to withstand a quake, and make the structure invisible to the earthquake waves, but if that cannot be done, dampen the waves as quickly as possible. 

From the answers, we tried to examine if the main problems of seismic under-evaluation may be related to the matter of the communication or to pitfalls in the communication process. Some concepts such as the probabilistic nature of the seismic hazard analyses, stationary earthquake rates, random uncertainties in the earthquake waves propagation are definitely out of the common experience, and they have to be simplified in the messages for the public ... 

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