| 講演要旨(和文) | | 一般にPS変換波はS波断面の構築では最も実用的であり,イメージングや物性解析等への利用が広がりつつある.近年、三成分MEMS加速度センサーの小型化,消費電力及び自己ノイズの低減等の技術革新に伴って,反射法地震探査における取得の効率的な三成分データ取得が実現可能な段階に到達している.また,長大展開による深部構造探査も広く実施されている.こういった背景の中,深部構造探査において多成分記録の取得やP-S変換波の利用価値が高まっている.今回、MEMS加速度センサーを用いた稠密長大展開による三成分反射法地震探査データを取得し、P-S変換波を利用した地殻構造探査を試みた。北上低地帯横断測線において適用した結果,P-S変換波によって堆積層中の地層境界および断層周辺の形態を捉えることができた.それらはP-P反射断面と整合的であり,今後の長大測線深部構造探査におけるP-S変換波利用の有効性を示す結果を得た. |
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| | 講演要旨(英文) | | The multi-component seismic data give us much information for the subsurface imaging and the analysis of rock properties, and the use of the P-S converted waves is now practical to obtain subsurface image constructed by shear waves instead of the S-S reflections. In these years, the technical innovation on MEMS-based accelerometers achieved efficient acquisitions of the multi-component data. In addition, the seismic exploration aiming the deep earth structures has been usually conducted. On these facts, the use of the P-S converted waves will increase in the deep reflection survey with the multi-component data. In this study, we applied P-S imaging to the three-component data acquired with the MEMS-based accelerometers on a 20km-long survey line in the Kitakami lowland, northeast Japan. The obtained P-S section clearly shows the structure from the sedimentary layers to the basement and the form of west dipping listric faults. The result from P-S processing is compatible with that from the conventional P-P processing. Our result represents the usefulness of the P-S converted waves in the deep seismic profiling. |
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