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摘要
To meet the demand of scientific assessment on earthquake monitoring capability of China Seismic Network (CSN) after the completion of the "Tenth Five-Year Plan" project and to further optimize the station-layout and improve the monitoring capability in the border and sea areas in China, this study investigated the seismic observation data of CSN with total 1001 stations during the period from 2008-10-01 to 2015-09-17. The distribution of seismic detection probability (P-E) and the minimum magnitude of completeness (M-p) were analyzed by using the method of "Probability-based magnitude of completeness" (PMC). In addition to mapping the seismic monitoring capability for entire CSN, we developed a new method named "seismic monitoring capability scale", and defined the seismic detection capability scale D-score to analyze the statistical characters and spatial distribution of the seismic detection capabilities for each national and regional stations, which was based on the amplitude contour curves. Additionally, the method of setting the "best objective function" of seismic detection capability was used to simulate the seismic monitoring capability improvement of CSN obtained by improving the conditions of observation. The result indicated that the seismic monitoring capability was significantly higher in the North China and southeast coastal areas of China. By contrast, the minimum magnitude completeness M-p in west China especially in the southern part of Qinghai-Tibet Plateau is M(L)4.5 and in offshore area is M(L)3.5. Considering the operational efficiency in terms of single seismic station, the results also revealed that the operation level of seismic network and the extent of seismic data analysis can impact the actual seismic detection capability significantly. It also can be found that the seismic detection capability was higher in Xinjiang and other sparse station areas, whereas lower in Guizhou area with middle station density. The D-score scoring results of the national stations are higher than the regional station systematically. The D-score of western frontier regions and southeast offshore areas such as Xinjiang and Fujian are significantly higher than that of the eastern region with dense stations. The simulation results showed that, under the existing station layout condition, through optimizing and improving the observation quality of seismic station, enhancing the operation and maintenance level, the monitoring capability of network and the detection capability of single station could be significantly enhanced in regions such as the western Inner Mongolia, the western Sichuan, the northern border region of Gansu-Qinghai, the Ordos block, most areas of Guizhou, the offshore area of China, the northern Korean Peninsula and the northern Indochina Peninsula.
- 出版日期2017-7
- 单位中国地震局
