针对中国地震台网“十五”项目建成后的地震监测能力科学评估的需求,为进一步优化台网布局、提升边疆海域等重点地区监测能力,本研究利用“基于概率的完整性震级”(PMC)方法,对中国地震台网1001个台站以及2008-10-01 2015-09-17期间实际产出的地震观测资料进行了研究,分析了指定震级档下的检测概率PE和最小完整性震级Mp的分布.除台网整体监测能力分布外,为直观地用单分值表述逐个台站的地震检测能力,本文发展了基于等振幅曲线的“地震检测能力评分表”,给出了国家台和区域台每个台站的地震检测能力评分统计特征和空间分布特征.此外,研究中还采用设定“最佳”地震监测能力目标函数的方式,模拟了通过改进观测条件可获得的地震台网监测能力提升的理论结果.研究结果表明,我国华北和东南沿海等东部地区地震监测能力较高,西部尤其是青藏高原南部地区MP仅约为4.5,近海海域MP仅约为3.5;从单个地震台站的运行效益角度,台网运行水平和地震观测资料的分析程度对台站的实际的地震检测能力影响显著,新疆等部分台站稀疏地区地震检测能力较高,而中等台站密度的贵州等部分区域相对较低;国家台的地震检测能力评分Dscore系统优于区域台,新疆等西部边疆地区,以及福建等东南沿海地区的Dsence明显高于台站密集的东部地区;模拟结果显示,在现有台站布局条件下,通过台站优化改造和提升运维管理水平,可显著提升对内蒙古西部、四川西部、甘肃青海的北部交界地区、鄂尔多斯地块内部、贵州大部分地区,以及我国近海海域、朝鲜半岛北部和中南半岛北部地区的地震监测能力.%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 (PE) and the minimum magnitude of completeness (My) 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 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 Mp in west China especially in the southern part of Qinghai-Tibet Plateau is ML4.5 and in offshore area is ML3.5.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 scoring results of the national stations are higher than the regional station systematically.The D 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.
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