青藏高原强震活动诱发因素研究

Study on inducing factors of strong earthquakes in Qinghai-Tibet Plateau

印度板块-欧亚板块碰撞导致的构造应力累积是引发青藏高原地震的动力机制,但地震是开放系统的产物,通过对青藏高原强震发震时间与太阳黑子活动周期、白赤交角变化周期、高原冰川消融时间呼应关系的分析,探讨了青藏高原近期的强震活动幕和特大地震活动趋势。研究结果表明,强震的发震时间大多处于太阳黑子数量由峰值到谷值的转化阶段和白赤交角由极大值至极小值的相位时段;冰川消融对地壳表层负载平衡的破坏作用导致青藏高原最近5次8.0级以上强震中除1950年察隅地震之外其余的4次特大地震均发生于春夏之交和秋冬之交的冰雪冻融过渡时期。结合青藏高原地震的天文背景、地文因素及地震的空间位置迁移规律,预测2025-2032年青藏高原巴颜喀喇断块可能迎来一次地震活动丛集期,2025年前后在该次级断块偏西区域可能发生8.0级左右的特大地震。

The tectonic stress accumulation caused by collision of Indian plate and Eurasian plate is the dynamic mechanism of earthquakes in the Qinghai-Tibet Plateau, but the earthquakes system is an open system, the occurring time of strong earthquakes in the Qinghai-Tibet Plateau has correlation with sunspot activity period, obliquity change period of the lunar orbit and glacial ablation time. The correlation was studied and the strong seismic activity trend was explored. The results show that the earthquakes occur in the conversion stage from peak value to valley point of sunspots and phase stage of the obliquity from the maximum to minimum, the 4 most earthquakes of the 5 great earthquakes occurred in the freeze-thaw transition periods of late spring and early summer and late autumn and early winter because of the destructive effect of glacial ablation on the isostasy. Based on combining the astronomical background and physiographic factor and the migration regularity of spatial position of earthquakes, the phases of earthquake clustering would probably appear at Bayan Har fault block in the years 2025 - 2032, an earthquake with about Ms8.0 maybe take place at western region of the sub-block in 2025.