Abstract:In the Tianshan region, the high pressure artesian water, high pressure oil-gas deposits and exposure of terrestrial heat anomalus area which are consistent with the distribution of the TianShan earthquake zone indicate that the dynamic condition of pore water pressure with high anomaly is likely to be an important machanism for triggering shallow focus earthquake. Based on many events, it can be considered that underground fluid has two kinds of anomalies before moderate and strong earthquakes in the TianShan earthquake zone. The first is the tendency anomaly during accumulated stage of stress-strain energy:The second is the abrupt anomaly of impending earthquake during pre-reteased stage of stress-strain energy. These two anomalies are entirely different in shape and time-space distribution, and show two quite different, physical and chemical processes during earthquake pregnant process. The seismic precursor components of fluid have own characteristics in different active zones. During the seismicity of the TianShan earthquake zone, the water level, petroleum amount, radon, conductance, and its gaseous components such as H2S, CH4 and CO2 always appear anomalous.
We predicted the Bogeda earthquake (Ms=5.3)on June 1.1983 by means of these two anomalies characteristics of the fluid components. This prediction was based on the synthetic observation and study of synthetics with many terms and components, it's perhaps important way to raise the research level of earthquake prediction for underground fluid.
