温度变化引起跨断层位移测量结果的年周期变化

ANNUAL PERIODIC VARIATIONS CAUSED BY THE CHANGE OF TEMPERATURE IN GEODETIC DISPLACEMENT MEASUREMENTS ACROSS FAULTS

  • 摘要: 本文首先给出了北京地区若干跨断层位移测量结果的年周期变化.而后,用二维非线性有限元方法,模拟了温度变化引起的跨断层位移测量结果的年周期变化.计算得到的应变量与野外观测大体一致.结果表明,在地壳介质不均一条件下,地表温度变化足以引起已观测到的种种复杂现象,诸如:存在两类基线,一类是当地表温度升高时增长;另一类是当地表温度升高时缩短.同时,存在两类水准变化,一类是断层热胀系数大的一盘,当地表温度上升时抬升;另一类则相反等等.一般说来,地壳介质是不均一的,因而温度对跨断层位移测量的干扰是不容忽视的.

     

    Abstract: This paper gives first the annual periodic variations in the geodetic data obtained from several observation stations for fault displacements in the Beijing region. Then, a two-dimensional non-linear finite element scheme is used to simulate the annual periodic variations caused by the change of temperature in the data of the displacement measurements across faults. The strains obtained from computation agree roughly with field measurements. The results indicate that for inhomogenous crustal medium, change of ground temperature can cause sufficiently a variety of complex observed phenomena. For examples, there are two kinds of baselines, one lengthens while the other shortens as the ground temperature rises; there are two kinds of leveling variations, the side of fault of large coefficient of thermal expanson rises as the ground temperature increases or conversely; and so on. However crustal media, in general, are inhomogenous, therefore temperature influence on displacement measurements across faults, should not be ignored.

     

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