2022 Fiscal Year Research-status Report
High resolution seismic refraction imaging of plate boundary structures by full waveform inversion off western Kii Peninsula, Nankai Trough
| Project/Area Number |
22K20392
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| Research Institution | Japan Agency for Marine-Earth Science and Technology |
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Principal Investigator |
Qin Yanfang 国立研究開発法人海洋研究開発機構, 海域地震火山部門(地震発生帯研究センター), 研究員 (20962343)
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| Project Period (FY) |
2022-08-31 – 2024-03-31
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| Keywords | seismic inversion / full waveform |
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| Outline of Annual Research Achievements |
As planned, I have obtained the starting model for full waveform inversion based on the first arrival travel time tomography. There are several things need to be prepared for application of the waveform inversion. First of all, the seismic data need to be preprocessed. Low signal to noise ratio of the original data bring in difficulties to the inversion and may cause artifacts. So I denoised the data properly. Another issue is the source wavelet for data modeling, which is a key for the inversion. I have tested several method to build up the source wavelet, and did the forward modeling by use each of them, respectively. After comparison, I chose the best one which can predict the first arrivals properly. After that, I need to design a strategy and run the inversion tests.
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| Current Status of Research Progress |
Current Status of Research Progress
2: Research has progressed on the whole more than it was originally planned.
Reason
Although there are many difficulties during the data process, I had got rid of the problems one by one and progress as planned. Now the rest part of work will focus on the inversion parameters testing.
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| Strategy for Future Research Activity |
For the inversion parameters tests, first of all, I need to judge which set of parameters could give a proper result. To check these, forward modeling and inversion need to do iteratively, and this would be the most complex and time consuming step, and chanlleging. It is the key step and decide the final interpretation. A lots of references need to be read and understand carefully. I wish I can progress smoothly.
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| Causes of Carryover |
JPGU 2023 conference participation; AGU 2023 conference participation; visiting of the international collaborators; purchase some hardwares.
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