Minimum Norm Inversion of Magnetic Anomalies with Application to Aeromagnetic Data in the Tanna Area, Central Japan.
Minimum Norm Inversion of Magnetic Anomalies with Application to Aeromagnetic Data in the Tanna Area, Central Japan.
复制标题
磁异常最小范数反演及其在日本中部塔纳地区航磁数据中的应用。
DOI：
10.5636/jgg.47.295
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发表时间：
1995
期刊：
影响因子：
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通讯作者：
T. Nakatsuka
中科院分区：
文献类型：
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作者：
T. Nakatsuka
本文提出了一种改进的磁化强度成图方法，它考虑了观测区周围震源体的副作用，可以从地下结构的角度解释磁异常。该问题通常是欠定的，可以用共轭梯度法迭代求解。渐近迭代给出了最小欧几里德范数解，以适用于地下建模。该方案进行了测试，对合成数据，以评估其性能，并应用于实际的航磁数据。通过对多摩地区航磁异常的分析，得出了磁化强度分布模式，该模式与活动断裂有较好的相关性。低磁化强度出现在Tanna断层南部的西部和北部的东部，以及在Ukihashi中部和西部断层之间的狭窄地带。它们与高破裂带有很好的对应关系，并将塔纳断层周围的四分之一模式解释为走滑断层所带来的挤压应力场的影响。
An improved method of magnetization intensity mapping is proposed to interpret magnetic anomalies in terms of subsurface structure, where the side effect of source bodies surrounding the observational area is taken into account. The problem, which usually becomes underdetermined, can be solved iteratively by the conjugate gradient method. The asymptotic iteration gives the minimum Euclidean norm solution, to be suitable for subsurface modeling. This scheme was tested against synthetic data to evaluate its performance and applied to actual aeromagnetic data. From the analysis of aeromagnetic anomalies in the Tama area, a model of the distribution of magnetization intensity was derived, which revealed good correlation with active faults. Lower magnetization intensities appeared to the west of the southernpart and to the east of the northernpart of the Tanna fault, and in a narrow zone between the Ukihashi central and west faults. They were well correlated to highly fractured zones, and the quadrant pattern around the Tanna fault was interpreted as the effect of the compressional stress field brought about by strike-slip faulting.