Abstract

The Detection of Electromagnetic Emissions Transmitted from Earthquake Regions (DEMETER) microsatellite-monitored data (IAP and ISL) were employed in investigating pre- (30 days) and post- (10 days) perturbations in ionospheric parameters associated with the M6.8 Eastern Honshu (Japan) earthquake (EQ) of July 23, 2008. The results constrained by synchronously monitoring geomagnetic indices data: Kernnifzer digit and disturbance storm time (Dst), revealed strong seismic event-induced disturbances three weeks to 5 days before the seismic event. The geomagnetic indices data were used in filtering normal geomagnetic disturbances from the seismic counterparts, thereby constraining the interpretations. The total ion density measured in per cubic centimeter (cm⁻³) recorded variations of 7.90, 4.51, and 5.92 on days-20, -19, and -16, respectively, from the earthquake day during the night time half orbit observations. Contemporaneously, perturbations of 8.81 were observed for electron temperature measured in Kelvin (K) five days afore the earthquake. The geomagnetically quiet state of the ionosphere during the pre-seismic days suggests that the observed disturbances are seismogenic. More researches should be encouraged in this area to deepen their applications in earthquake monitoring and prediction.

Research Highlights

• Use of DEMETER data for earthquake prediction.

• Ionospheric plasma parameters used in detecting seismo-genic induced perturbations.

• Quiet atmospheric geomagnetic perturbations before the earthquake is seismogenically induced.

• Seismo-genic anomalies are promising for short-term earthquake prediction.

中文翻译：

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2008 年 7 月 23 日日本本州东部 M6.8 地震之前的电子温度和离子密度扰动

摘要

从地震区传输的电磁辐射检测 (DEMETER) 微卫星监测数据（IAP 和 ISL）被用于调查与M 6.8 Eastern Honshu相关的电离层参数的前（30 天）和后（10 天）扰动（日本) 2008 年 7 月 23 日发生的地震 (EQ)。受同步监测地磁指数数据限制的结果：Kernnifzer 数字和扰动风暴时间 (Dst)，揭示了在地震事件发生前三周至 5 天的强烈地震事件引起的扰动。地磁指数数据用于过滤来自地震对应物的正常地磁扰动，从而限制解释。以每立方厘米 (cm ^-3) 在夜间半轨道观测期间分别记录了地震日在第 20、-19 和 -16 天的 7.90、4.51 和 5.92 的变化。同时，在地震前五天以开尔文 (K) 为单位测量的电子温度观测到 8.81 的扰动。地震前几天电离层的地磁安静状态表明观察到的扰动是地震发生的。应鼓励在这方面进行更多的研究，以深化其在地震监测和预测中的应用。

研究亮点

• 使用 DEMETER 数据进行地震预测。

• 用于检测地震诱发扰动的电离层等离子体参数。

• 地震前安静的大气地磁扰动是由地震诱发的。

• 地震成因异常对于短期地震预测很有希望。