The research on the space-time coherence of Xianshuihe fault zone in the process of seismogeny

In this paper, a kind of data analysis method is used to research the space time coherence of Xianshuihe fault zone in the process of seimogeny. It is proved that, the space time coherence of Xianshuihe fault zone, in the process of seismogeny, really exists. The greater the earthquake magnitude of a fault section, the greater is its influence on the 'neighboring' sections. To a strike fault zone which bears compressive stress, the fault sections are 'series connected'. That is to say, once an earthquake happens on a fault section, the time of seismogeny in the neighboring fault sections will be shortened, therefore, this earthquake has 'an effect of hastening the occurrence of earthquakes in neighboring fault sections'. It is an inevitable rule for the Xianshuihe fault zone that the earthquake quiescent period and the earthquake active period occur alternatively. To the Xianshuihe fault zone, the slip predictable model does not tally with the actual situation, while the improved time predictable model tallies with the fact quite well. The data analysis method used here, which is used to examine the earthquake prediction models, is put forward on the basis of historical earthquake records. This kind of method and the relative conclusions have important reference value on the establishment of earthquake prediction models.

Temporal gravity changes before the 2008 Yutian Ms7.3 earthquake

Based on the data of the repeated gravity observation network in Chinese mainland since 1998, we analyzed the temporal changes of regional gravity field before the 2008 Yutian Ms7.3 earthquake. The result shows some mid-to-long term （two to ten years） changes during the earthquake＇ s preparation. Notable fea- tures are a gravity increase lasting several years and a relatively large-scaled gradient zone of gravity change, the former indicating a continuous energy accumulation and the latter a possible location of seismic rupture. These gravity changes showed a trend of increase-accelerated increase-decelerated increase, similar to that of the Tangshan Ms7.8 earthquake in 1976. The maximum accumulated gravity change related to the earthquake reached 200 × 10 -8 ms -2.

Research of pattern dynamics parameters of crustal deformation field in seismogenic process

There are fractal character and fractal dimensions with time in crustal deformation field of seismogeny process.The occurrence of strong earthquake is after the process of the dimension lowering, entrolpy decreasing and ordering,the fractal dimension, entropy value and order degree are all resumed normal datum after the occurrence of strong earthquake, it reflects the evolution of crustal deformation field is the process from the homogeneous deformation - heterogeneous deformation - disturbance - homogeneous deformation. We regarded the fractal dimension, information entropy and order degree as pattern dynamics parameters of crustal deformation field to use, and the deformation localize process is quantitatively described by the parameters.

The crustal fluid evolution and the causes of earthquakes(Ⅲ)

This paper is the third one of a series of three papers on the fluid evolution of the crust upper mantle and the causes of earthquakes. Based on the last two papers, a model of the crustal resistivity structure and the deep seated fluid evolution is presented, and also a seismogeny theory is set up, which is called the potential kinetic energy transformation model. In this model, the crustal deep seated fluid evolution is considered to take the most important effect on the seismogenic process. Taking the Tangshan M 7.8 earthquake of 1976 as an example, the earthquakes occurred in a pull apart rifting basin are analyzed, and finally the crust outgassing in the seismogenic processes is discussed, referring to the here presented theory of seismogeny.

Study on the effect of underground hot water on fracturing and earthquake activities

Utilizing the geological exploring information of Houhaoyao area and digital seismic network's data of Huailai area, the author studied the role of underground fluids (hot water) in the fracturing activities and in the processes of seismogeny. The results show that the shear stress between two blocks of the fault is decreased rapidly and the vertical fault throw is obviously increased at the fracture segments where there is underground hot water action. With the vertical fault throw increasing, the shear stress transfers to two ends of the fault at the place where there is no underground hot water action, and the earthquake probably develops at these two ends of the fault.

Research on the Dynamic Evolution of Deformation Field and the Acquisition of Seismogenic Information Before Lijiang Earthquake With Ms7.0

By using the integral dynamic adjustment of the "segmentation rate," this paper processes the leveling repetition measurement data of the Dianxi(western Yunnan)area since the 1980s,makes the fitting of the velocity surface for vertical deformation with multi-surface function,and splits information of the vertical deformation field.The dynamic evolution of the deformation field and vertical deformation information norm-shear deformation,extension deformation,volumetric deformation,and quasi acceleration,which are the distribution characteristics of variation,are studied by using the information split before the Lijiang earthquake with MS7.0(February 3,1996)in the north of the Dianxi(western Yunnan)leveling network.The results indicate that in Dianxi(western Yunnan)area,the acute vertical differential movement of the large-scale deformation velocity high gradient belt and high information norm distribution in the Lijiang,Yongsheng,and its adjacent areas in the middle stage of the 1980s is the reflection