临震天体引潮力和地面长波辐射OLR异常

Preliminary study on the tidal force and Outgoing Longwave Radiation change

摘要:

利用天体引潮力周期变化模型和地面长波辐射(OLR)数据资料，分析2010～2011年云南、西藏地区的4次M5.0以上地震震前OLR异常，探讨了诱发地震的外部因素，即天体引潮力周期与红外异常发展的关联特征。结果显示:以临近发震时刻所在周期引潮力值最低点日期为OLR 参照背景，获取的地震前后NOAA长波辐射OLR日增量分布图像显示:震中附近热异常明显，异常受构造控制，且其分布与断裂关系密切;异常演化经历起始-加强-高峰-衰减-再增强-发震-平静的过程，符合岩石因应力增加而破裂的规律。一方面表明地应力的临界状态演化过程可通过OLR 辐射变化来反映。另一方面表明引潮力可以改变构造内部地应力的状态。

Abstract:

Based on the cycle process of the tidal force of celestial body and the Outgoing Longwave Radiation (OLR) data，we analyzed the relationship between the tide force and infrared abnormal changes before and after 4 earthquakes that occurred at the regions of Yunnan and Tibet of China． The images of the daily increment of OLR by choosing the minimum of the tidal force period approaching the earthquake as reference background，and subtracted it from the surface OLR with day by day，same time and same scope，showed that the infrared anomalies were obvious near the epicenter，the anomaly expansion were controlled by the fault structure，and the anomaly distribution is closely related with fracture; the process of anomaly evolution was as follow: Initial infrared rise—enhancement—reaching peak—attenuation—re-enhancement— earthquake occurred—return to baseline． It was consistent with the regulation of rock broken procession under stress load． It implied that the evolution process of the critical condition of crustal stress can be reflected through changing of OLR radiation and the tidal force plays as an inducement role for changing the accumulate-unbalance of the structure internal crustal stress．