Precise Measurement Of Seismic Velocity And Velocity Variation By Correlated Detection

Earthquake is one of the grisly natural disasters that human have to face. Although People have been hoping to mitigate the earthquake disaster by earthquake forecast for million years, earthquake forecast is still an international science puzzle. One of the most important physical keys to forecast earthquake is that the deep stress varies with time. Theoretically, we can obtain the deep stress variation with time by seismic velocity variation. Because the stress variation is very weak in the interior earth, the capability to detect the seismic velocity and the precision to measure the seismic velocity must be high. The measurement methods in existence can't achieve to the precision. There is a seismic science problem all along, which is to enhance the observe precision greatly. How can we solve the problem? Theory and methods in information field give us some revelations. Correlated detection is a new technique which is developed in information science in the 19th century. The technique is applied maturely in information field. Importing the correlated detection into seismic detection, that making the seismic velocity measurement precisely and becoming possible.On the basis of theory about correlated detection and influencing factors, we designed a suit of observation system and method which involves the active seismic sources, observe instruments, survey disposal, seismic source excitation, data process, resultant interpretation and so on. And this progresses in various range and time scale experiments to verify the feasible research. We measured the seismic velocity precisely in the middle scale experiment, proved the capability of correlated detection to enhance the detection and the feasibility of precision to measure the seismic velocity, and acquired the promising results. And then, we enlarged the experiment scale and obtain favorable outcome. The Kunming experiment made the dynamic monitor about seismic velocity variation come true.We get the following conclusions:1) The observation system and method that we have established contain active seismic source's repeated excitation, record about the seismic data by high sensitivity...