基于速率累加法提取地磁谐波振幅比异常指标  

Anomaly Indicators Extracted of Geomagnetism Harmonic Amplitude Ratio Based on Rate Accumulation Algorithm

作　　者：李霞 冯丽丽[1,2] 赵玉红 刘磊[1,2] 苟智栋 LI Xia;FENG Lili;ZHAO Yuhong;LIU Lei;GOU Zhidong(Geodynamics Field Observation and Research Station of Qinghai-Tibet Plateau,CEA,242 Tsaidam Road,Xi’ning 810017,China;Qinghai Earthquake Agency,242 Tsaidam Road,Xi’ning 810017,China)

机构地区：[1]中国地震局青海格尔木青藏高原内部地球动力学野外科学观测研究站,西宁市810017 [2]青海省地震局,西宁市810017

出　　处：《大地测量与地球动力学》2022年第3期303-311,共9页Journal of Geodesy and Geodynamics

基　　金：中国地震局地震科技星火计划(XH21037Y);中国地震局震情跟踪定向工作任务(2021010413);中国地震局青海格尔木青藏高原内部地球动力学野外科学观测研究站专项。

摘　　要：利用谐波振幅比方法分析青海地区磁通门秒采样观测资料,通过速率累加法分析连续数据的逐日变化速率,再根据需要对分析时段进行累加计算,识别数据资料的异常变化。进一步分析异常变化与强震的关系,梳理总结青海地区磁通门秒数据谐波振幅比的特征规律,完成从定性到定量的异常认识。结果表明,地磁谐波振幅比计算结果通过速率累加处理后的曲线持续上升为正常,持续下降和水平波动为异常;当异常持续时间大于1 a,同时异常曲线数量超过1/2时,台站周围发生5级以上地震的概率较高,曲线周期范围主要集中在20~170 s内;震级与震中距成正比,即震级越高,震中距越大。We use the harmonic amplitude ratio method to analyze the fluxgate second sampling observation data in Qinghai area.On this basis,we apply the rate accumulation method to analyze the daily change rate of continuous data.Then,according to the need to identify the abnormal changes of data,we carry out the accumulation calculation of the analysis period.We further analyze the relationship between the abnormal change and strong earthquake,and summarize the characteristics of harmonic amplitude ratio of fluxgate second value in Qinghai region so as to complete the process from qualitative to quantitative recognition of anomalies.The results shows that the curves of the geomagnetism harmonic amplitude ratio after rate accumulation processing are continuously rising to normal,while the curves are continuously decreasing and the horizontal fluctuation are abnormal.When the duration of the anomaly is more than 1 a and the number of anomalous curves is more than half,the probability of M≥5 earthquakes around the station is high,and the curve period mainly ranges from 20 to 170 s.The magnitude is proportional to the epicenter distance,that is,the higher the earthquake magnitude,the greater the epicenter distance.

关 键 词：地磁谐波振幅比 速率累加法 异常判据与指标 

分 类 号：P315[天文地球—地震学] P318[天文地球—固体地球物理学]