汶川8.0级地震仪器烈度与宏观烈度对比分析

Comparative Analysis between Instrumental and Macroseismic Intensity during the Wenchuan M8.0 Earthquake

摘要:

利用2008年汶川M8.0地震获得的强震动记录数据，根据《仪器地震烈度计算暂行规程》计算得到各台站处的仪器地震烈度值，分析仪器地震烈度与宏观地震烈度的对应关系，研究该仪器烈度计算方法的适用性。结果表明，利用该算法所得的仪器烈度值与宏观烈度完全吻合的比率为47.5%，偏差±1度以内的比率为89.1%，说明二者对应情况较为理想，仪器烈度可在一定程度上客观反映实际的震害情况；在各宏观烈度区内仪器烈度值虽然具有一定的离散性，但其均值与宏观烈度区值的偏差相对较小，均控制在±0.3度以内。另外，文中还绘制了汶川地震仪器烈度分布图，虽然与宏观烈度在整体分布上具有一定的对应关系，但受多种因素的影响，仪器烈度分布与宏观烈度分布不可能完全一致。仪器烈度与宏观烈度的概念和属性有所差异，发挥的作用也不尽相同，不应混淆和相互替代。

Abstract:

Using the strong motion records of the Wenchuan M8.0 earthquake in 2008, the instrumental intensity at each station is calculated in accordance with the algorithm from the provisional regulation; moreover, the corresponding relationship between instrumental and macroseismic intensity is analyzed to discuss the applicability of the calculation method of instrumental intensity. Results show that stations with the same intensity value account for 47.5%, and stations with deviations of less than 1 degree account for 89.1%. These results indicate that instrumental and macroseismic intensity have an ideal corresponding relationship, and instrumental intensity can objectively reflect the actual earthquake damage. The instrumental intensity values in each macroseismic intensity area have certain discreteness, but the deviations between the mean instrumental and macroseismic intensity values are relatively small, which can be controlled within ±0.3 degree. Additionally, the distribution map of the instrumental intensity of the Wenchuan earthquake is drawn. Although a certain correspondence exists between instrumental and macroseismic intensity in the overall layout, they cannot be completely consistent due to the influence of some factors. The concept, properties, and functions of instrumental and macroseismic intensity vary and thus should not be used interchangeably.