Abstract

In present study soil radon (Rn-222) emanation, geomagnetic total field intensity (B_total), and total electron content (TEC) in ionosphere prior to M_w 5.5, Kokrajhar, Assam earthquake of September 12, 2018 were investigated using multiparametric geophysical observations at Ouguri Hills, Tezpur, Assam. Prominent anomalies were observed in the soil Rn-222 emanation, B_total and TEC time series prior to the event and are discussed. It was observed that soil Rn-222 persisted anomalies 50 days prior to the earthquake event. The correlation coefficient between soil Rn-222 with soil temperature and soil pressure was estimated to be feeble, 0.2 and –0.4 during the investigation period. Similar anomalies were observed 26 days prior to the earthquake event in B_total. The ionospheric TEC also persisted anomalies 17 days prior to the event. The amount of anomalous values observed for soil Rn-222, B_total, and ionospheric TEC ranged between –15.61 to 25.02 KBq/m³, –83.33 to 10.50 nT and –13.06 to 7.09 TECU below LB and above UB respectively. An increase of 1.92 nT and a decrease of –36.77 nT of daily rate change was observed during the anomaly period compared to the normal days. The study revealed possibility of precursor detection through multi parametric approach from ground to ionosphere level.

中文翻译：

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基于卫星和地面观测数据的阿萨姆邦（印度东部喜马拉雅山）地震前兆检测的多参数方法

摘要

在本研究的土壤氡（RN-222）流溢，地磁总场强（乙_总），并在电离层至M电子总含量（TEC）之前_瓦特5.5，科克拉贾尔，9月12日的阿萨姆地震，2018，使用多参数地球物理研究阿萨姆邦Tezpur的Ouguri Hills观测。在土壤RN-222散发，观察到显着的异常乙_总以及活动之前的TEC时间序列，并进行了讨论。据观察，土壤Rn-222在地震发生前50天持续异常。在研究期间，土壤Rn-222与土壤温度和土壤压力之间的相关系数估计很小，分别为0.2和–0.4。类似异常中未观察到地震活动开始前26天乙_总。事件发生前17天，电离层TEC也持续存在异常。土壤Rn-222，B _total和电离层TEC的异常值数量在–15.61至25.02 KBq / m ^3之间，–83.33至10.50 nT和–13.06至7.09 TECU分别位于LB以下和UB以上。与正常天相比，异常期间每日速率变化增加1.92 nT，减少–36.77 nT。该研究揭示了通过多参数方法从地面到电离层水平进行前体探测的可能性。