利用减组合滤波方法对2008—2013年云南省内7次M≥5.5地震前3个月10个台站的水管倾斜观测资料进行处理,消除潮汐改正成分和零漂,探寻短临同步异常变化。结果 表明,减组合滤波方法提取的高频成分,在震前存在同步异常,可尝试用于短临跟踪工作中; 利用“Nakai拟合模型”求解得到潮汐响应率和线性漂移速率在短临阶段均未表现出易识别的异常,其反映的信息尚需进一步挖掘。
Using the reducing combination filtering method,we processed the water tube tilt observation data recorded by 10 stations in Yunnan within 3 months before 7 times of M≥5.5 earthquakes since 2008,and eliminated the tidal correction and zero drift to look for the synchronous abnormal changes in the short-term and imminent stages.The results showed that after extracting the high frequency component by reducing combination filtering method,we found that the synchronous abnormal changes were widespread before earthquakes,which could be applied in short-term tracking.The tidal response rate and linear drift rate which were solved by Nakai fitting model did not show the easy identified anomalies in short-term and imminent stages,which reflecting information needs to be further explored.
