以门源M6.9地震为契机的祁连带中东段地震热红外异常区域特征研究

Characteristics of thermal infrared anomalies in the middle-eastern segment of Qilian seismic belt guided by Menyuan M6.9 earthquake

以中国静止气象卫星亮温资料为数据基础,使用小波变换和功率谱估计法研究2022年1月8日门源M6.9地震前的热辐射异常,并对祁连带中东段以往震例的热辐射异常作回溯性研究。门源6.9级地震的热辐射异常发展过程可分为3个阶段:初始演化阶段、增强持续阶段、减弱消失阶段。面积最大时强辐射区的面积约为8万km^(2),地震发生在其西北部。相对功率谱峰值为平均值的17倍,地震发生在峰值后82天。大面积、高强度的热辐射状态持续时间长是此次异常的显著特点。祁连带中东段的几次地震前均出现过热辐射异常,其特征可为该区震情判定不断积累经验,以期形成可作为判定指标的区域震例库。

Based on the brightness temperature data obtained from Chinese geostationary meteorological satellite,this paper studied the thermal radiation anomalies before the Menyuan M6.9 earthquake on January 8,2022 by using the wavelet transform and the relative change of power spectrum,and made a retrospective study on the thermal radiation anomalies of previous earthquakes in the middle-eastern Qilian seismic belt.The development process of thermal radiation anomaly of the Menyuan M6.9 earthquake can be divided into three stages:initial evolution stage,strengthening and persisting stage,weakening and disappearing stage.The largest area of intense radiation was about 80000 km^(2),and the earthquake occurred in the northwest of the region.The peak value of the relative power spectrum was 17 times the average value,and the M6.9 earthquake occurred 82 days after the peak value.The significant feature of the anomaly is the large area and long duration of high intensity thermal radiation.The characteristics of thermal radiation anomalies before several earthquakes in the middle-eastern Qilian seismic belt can accumulate experience for the judgment of earthquake situation in this area.