CEEMD-小波降噪与高频GNSS/强震数据融合的震源机制解精度提升

Enhancing the precision of focal mechanism through CEEMD-wavelet denoising and high-rate GNSS/strong-motion data fusion

  • 摘要: 为了克服高频GNSS数据在震源机制解反演中的噪声敏感性问题,本文提出了一种基于相关系数的互补集合经验模态分解(complementary ensemble empirical mode decomposition,CEEMD)-小波降噪与多源融合反演框架,实现对高频GNSS定位精度的提升,进而提高震源机制解反演精度. 以2018年美国阿拉斯加安克雷奇Mw7.0地震为案例,原始高频GNSS、降噪高频GNSS、强震仪及融合数据的波形拟合优度(VR)分别为67.2%、76.0%、80.1%、95.1%,降噪处理使拟合精度提升约10%,多源数据融合后精度提升达28%. 通过对比震源机制解参数与全球质心矩张量(Global Centroid-Moment-Tensor,GCMT)和美国地质勘探局(United States Geological Survey,USGS)标准解的偏差分析,证实了融合数据反演结果的一致性. 该联合反演框架不仅显著提升了高频GNSS数据的信噪比和震源机制解的可靠性,还为区域应力场分析提供了多源数据融合技术路径,对地震预警系统优化和断层运动状态研究具有重要实践价值.

     

    Abstract: We aim to overcome the problem of noise sensitivity of high-frequency GNSS data in source mechanism solution inversion. We proposes a Correlation-based Complete Ensemble Empirical Mode Decomposition (CEEMD)-Wavelet denoising and multi-source fusion inversion framework, aiming to enhance high-frequency GNSS positioning accuracy and thereby improve the precision of source mechanism inversion. Taking the 2018 Anchorage, Alaska, America Mw 7.0 earthquake as a case study, the variance reduction (VR) values for raw high-frequency GNSS, denoised high-frequency GNSS, strong-motion seismograph, and fused data reached 67.2%, 76.0%, 80.1%, and 95.1% respectively. The denoising process improved waveform fitting accuracy by approximately 10%, while multi-source data fusion achieved a 28% enhancement. Comparative analysis of source parameters (strike/dip/slip angles, magnitude, depth) with GCMT and USGS reference solutions confirmed the consistency of fusion-based inversion results. This integrated framework not only significantly enhances the signal-to-noise ratio of high-frequency GNSS data and the reliability of source mechanism solutions, but also provides a multi-source data fusion methodology for regional stress field analysis. It demonstrates substantial practical value for optimizing earthquake early warning systems and investigating fault motion dynamics.

     

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