ESTIMATION OF CRUSTAL STRUCTURE IN CENTRAL AND WEST JAPAN FROM WAVE-FORM MODELING OF REGIONAL PL WAVES

被引：7

作者：

FUJITA, M ^{[1
]}

NISHIMURA, K ^{[1
]}

机构：

[1] KYOTO UNIV,FAC SCI,DEPT GEOPHYS,SAKYO KU,KYOTO,KYOTO 606,JAPAN

来源：

PURE AND APPLIED GEOPHYSICS | 1993年 / 140卷 / 04期

关键词：

PL WAVE; WAVE-FORM MODELING; S VELOCITY; UPPER CRUSTAL STRUCTURE; INVERSE METHOD; REGIONAL DIFFERENCE;

D O I：

10.1007/BF00876577

中图分类号：

P3 [地球物理学]; P59 [地球化学];

学科分类号：

0708 ; 070902 ;

摘要：

An inverse method of modeling the regional PL waveform with the predominant period of about 20s was developed to estimate the average S-velocity structure of the upper crust. Applicability of the waveform modeling was confirmed by the results of the numerical experiments: the PL waveform is most sensitive to the S velocity in the upper crust, whereas it is not affected significantly by errors involved in the focal mechanism solution and focal depth determination when the PL wave is well developed. The method was applied to the observed seismograms recorded in central Japan from the earthquakes with epicentral distances 300-500 km. As a result, distinct regional differences were found in the upper crustal S velocity; in particular, between the southern Shikoku district, west Japan, and the southern Chubu district, central Japan, and between the mountainous and the coastal areas in the southern Chubu district. These differences are in agreement with the general features of P-velocity structures obtained by explosion experiments and by analyses of natural earthquakes. Our method is effective to the extent that the crustal structure along the propagation path can be assumed a horizontally layered structure; it is not applicable when the sensitivity of the PL waveform to the error in the focal mechanism solution is exceptionally high.

引用

页码：569 / 592

页数：24

共 19 条

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