[1]ZHANG Yongqi,HAN Meitao,ZHANG Enhui,et al.Multi-scale Wavelet Decomposition and Interpretation of Gravity Anomalies in the Weihe Basin and Its Adjacent Areas[J].Journal of Seismological Research,2022,45(01):75-87.[doi:10.20015/j.cnki.ISSN1000-0666.2022.0009
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Multi-scale Wavelet Decomposition and Interpretation of Gravity Anomalies in the Weihe Basin and Its Adjacent Areas
Journal of Seismological Research[ISSN 1000-0666/CN 53-1062/P] Volume:
45
Number of periods:
2022 01
Page number:
75-87
Column:
Public date:
2022-01-20
- Title:
- Multi-scale Wavelet Decomposition and Interpretation of Gravity Anomalies in the Weihe Basin and Its Adjacent Areas
- Keywords:
- the Weihe Basin and its adjacent areas; Bouguer gravity anomaly; multi-scale wavelet decomposition; the Moho depth
- CLC:
- P315.726
- DOI:
- 10.20015/j.cnki.ISSN1000-0666.2022.0009
- Abstract:
- Based on the EGM2008 gravity field model,we obtain the Bouguer gravity anomalies in the Weihe Basin and its adjacent areas.And using the wavelet multi-scale decomposition method we decompose the Bouguer gravity anomalies to 4-order wavelet approximation and details.Based on the average,radial,ogarithmic power spectrum,we calculate the average depth of the field source corresponding to 1st,2nd,3rd,and 4th order wavelet approximation and details.Then we analyze the obtaine gravity field on the baiss of the regional geological and seismic data,and get the following conclusions:① The Bouguer gravity anomalies in first-order tectonic units,the Ordos block,the Weihe basin,and the Qinling orogenic belt,are obviously different,and the Bouguer gravity anomalies within each tectonic unit are horizontally different.The trend,scale,and distribution of the Bouguer gravity anomalies correspond with the secondary structural regions and the major faults in the research areas.② The 1st to 4th-order details of the Bouguer gravity anomaly in the Weihe basin and its adjacent areas correspond to the field source information at depths between 4 km and 23 km.The details of the Bouguer gravity anomaly at different orders reveal the following crustal structure features:The crustal structure in the east and west of the southern margin of the Ordos block is obviously different; The boundaries of sags and uplifts in the Weihe Basin are clear and the fault's boundaries are consistent with the gravity anomaly boundaries; The continuity of gravity anomalies in the Qinling orogenic belt is poor,and the variation characteristics of gravity anomalies in the east region are obviously different with those in the west.③ The distribution of the Bouguer gravity anomalies in the Weihe Basin and its adjacent areas has a clear mirror-image relation with the Moho depth.The earthquakes in the Weihe Basin and its adjacent areas mainly occur in the Liupanshan-Longxian-Baoji fault zone,at the intersection of the Weihe fault and the Weinan Yuanqian fault,and at the intersection of the Hancheng fault and the Shuangquan-Linyi fault.In addition,the gravity anomalies in the Weihe basin and its adjacent areas are mainly affected by the residual density of the middle and upper crust,which may be the reason why the shallow-focus earthquakes are prone to occur in this area.
- References:
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Last Update:
2022-01-20