Study On Wave Velocity Ratio In Inner Monglia

This paper studies the geological structure and seismic activity characteristics inInner Mongolia autonomous region, on the basis of obtained the eastern InnerMongolia region, central and western regions’ mainly the tectonic units and the mainactive faults and earthquake distribution, and seismic activity in the Inner Mongoliaautonomous region, in recent years, combined with work experience, Inner Mongoliaautonomous region earthquake the study area can be divided into one total area, threepoints area, total area of the Inner Mongolia region, its main scope is37°-53°N,97°,127°E; Three for the eastern, central and western areas, respectively, the east:41.5°-51°N,114.5°-124.6°E; Middle:38.5°-43.5°N,108°,116°E; West:37°-43°N,99°,110°E.This study used the multi-station method for the calculation of wave velocityratio. In order to make data can more fully reflect the research area of the wavevelocity ratio information, collected analog and digital observation report between1976and2012. evaluated the earthquake monitoring ability in Inner Mongolia regionsince1976, combined previous research results, the maximum possible to eliminatethe factors that affect the wave velocity ratio, then selected the ML2.0earthquakeswith magnitudes above, and at least four stations clearly recorded observations ofwave velocity ratio calculation,finally obtained average wave velocity ratio in InnerMongolia between1976-2012. Overall, the average velocity ratio of the eastern regionis lower than the region’s other two regional average velocity ratio, central andwestern region is higher than the ratio of the average velocity ratio of Inner MongoliaThese can be used as the average velocity ratio corresponding normal velocity ratiowithin the region background values for future changes in velocity ratio as abenchmark reference.In Inner Mongolia region and the three sub-regional spatial contours of velocityratio changes during the study found that the velocity ratio in Inner Mongolia thereare three high value area, and the more concentrated obvious. Geographically, fromeast to west, high value, mainly in NaiManQi-in fuxin area; Solid Yang-baotou area;WuYuan-low-amphibolite area. Low and wave velocity ratio of the area ofwulanchabu city geographically distributed mainly in northern, SiZiWangQi, andLinda lingle, qingshui river. Wave velocity ratio on spatial distribution of wholepresents the two high value zone of eastern, western, with low in central area.Within the region on three typical seismic studies, we found that the overallvelocity ratio before the earthquake showing a "drop-low-Recovery-earthquake"process. Abnormal duration of6months-10months, Appears low, if the speed backup to normal, will generally be in the1-2month period around4.5earthquakeoccurred.Change range of abnormal low, generally between3%5%, the variationbetween0.04-0.06. Also found that an earthquake occurred in the high values ofvelocity ratio contour around, usually away from the contour of the high velocity ratiovalue area, often occurs in low velocity ratio contour area.Occurs more easily in themountains and plains of the border region, such as alluvial plain areas. Analysis of thephysical mechanisms velocity ratio Inner Mongolia region, we found that acombination of previous proposed model can well explain the Inner Mongolia regionis characterized by abnormal changes in velocity ratio.