NUMERICAL INTERPRETATION OF SELF-POTENSIAL METHODE FOR INVESTIGATING FAULT
The geophysics research to observe the subsurface anomaly in Parongpong, West Bandung Regency, and West Java had been done. The research was conducted to analyze and interpret the location of fault by using self-potential method of fix-geometry model. Self-potential (SP) method is frequently used to...
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| Format: | Theses |
| Language: | Indonesia |
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| Online Access: | https://digilib.itb.ac.id/gdl/view/27292 |
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| Institution: | Institut Teknologi Bandung |
| Language: | Indonesia |
| Summary: | The geophysics research to observe the subsurface anomaly in Parongpong, West Bandung Regency, and West Java had been done. The research was conducted to analyze and interpret the location of fault by using self-potential method of fix-geometry model. Self-potential (SP) method is frequently used to identify subsurface structures based on electrical properties. Fix-geometry model is a kind of method which is used to observe SP anomaly along “x” axis which is occurred because of polarization of causative bodies such as sphere, cylinder, and sheet. The fault is a land fracture. Therefore in fix-geometry model, it is considered to represent the shape of the sheet. The estimation of the model parameters influenced by SP anomaly measured in the top of the fault structure was conducted by using Particle swarm optimization (PSO) of inversion process. The inversion scheme was first tested on a synthetic model, where a close agreement between the test parameters and the calculated parameters was achieved. The result of the inversion using synthetic data shows the correspondence between the calculation data and the observation data with the value of the objective function 3.6x10-4. Finally the scheme was carried out to invert the real observed SP anomalies. The results show that the presence of the fault was detected beneath the surface for the first line having electric dipole moment K = -180,10 mV, the fault center xo = 1374,08 meter, the half-fault a = 49.97meter, the polarization angle with respect to the horizontal plane ? = 60o, and the center depth z = 100.02 meter. However the fault was detected in second line having electric dipole moment K = -75,60 mV the fault center xo = 1074,8 meter, the half-fault a = 25 meter, the polarization angle with respect to the horizontal plane ? = 30o, and the center depth z = 132 meter. <p align="justify"> |
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