Scholarlink

<p>This study systematically analyzed the spatiotemporal evolution characteristics of geomagnetic anomalies before and after the 2013 Sichuan Lushan M7.0 earthquake and the Gansu Minxian M6.6 earthquake by constructing a geomagnetic diurnal variation model based on Taylor polynomial fitting, combined with midnight mean values of the geomagnetic F component from China’s geomagnetic observatory network. The results reveal distinct differences in anomaly patterns, namely per-sistent positive anomalies were observed in the epicentral region of the Lushan earthquake, while significant negative anomalies characterized the Minxian earthquake zone. This differential response reveals the modulating effect of the electrical structure of the seismogenic medium on space electromagnetic disturbances, namely positive anomalies may correspond to the stage of stable stress accumulation in intact rock, while the expansion of negative anomalies may reflect an amplification of electromagnetic disturbances induced by fracture expansion. Further analysis demonstrates that both anomalies exhibit a three-stage evolutionary pattern, namely pre-seismic accumulation, co-seismic release, and post-seismic adjustment. The phase transitions in these anomalies are closely correlated with regional tectonic stress accumulation and destabilization processes. These findings not only provide new evidence for the physical interpretation of seismomagnetic precursors but also establish a theoretical foundation for developing earthquake prediction methods based on the dynamic evolution of geomagnetic anomalies.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Characteristics of geomagnetic anomalous evolution before and after two major earthquakes: a Taylor polynomial model analysis

  • 期刊论文

  • 发表日期：

    2025年11月24日

查看全文
  • Lei Zhang,
  • Jian-Guo Zhang,
  • Xuan-Ye Shen,
  • Hao Lian,
  • Ji-chao Duan

摘要

This study systematically analyzed the spatiotemporal evolution characteristics of geomagnetic anomalies before and after the 2013 Sichuan Lushan M7.0 earthquake and the Gansu Minxian M6.6 earthquake by constructing a geomagnetic diurnal variation model based on Taylor polynomial fitting, combined with midnight mean values of the geomagnetic F component from China’s geomagnetic observatory network. The results reveal distinct differences in anomaly patterns, namely per-sistent positive anomalies were observed in the epicentral region of the Lushan earthquake, while significant negative anomalies characterized the Minxian earthquake zone. This differential response reveals the modulating effect of the electrical structure of the seismogenic medium on space electromagnetic disturbances, namely positive anomalies may correspond to the stage of stable stress accumulation in intact rock, while the expansion of negative anomalies may reflect an amplification of electromagnetic disturbances induced by fracture expansion. Further analysis demonstrates that both anomalies exhibit a three-stage evolutionary pattern, namely pre-seismic accumulation, co-seismic release, and post-seismic adjustment. The phase transitions in these anomalies are closely correlated with regional tectonic stress accumulation and destabilization processes. These findings not only provide new evidence for the physical interpretation of seismomagnetic precursors but also establish a theoretical foundation for developing earthquake prediction methods based on the dynamic evolution of geomagnetic anomalies.