Temporal and spatial analyses on seismo-electric anomalies associated with the 27 February 2010 <i>M</i> = 8.8 Chile earthquake observed by DEMETER satellite

Abstract

Abstract. This paper studies seismo-electromagnetic anomalies observed by the French satellite DEMETER (Detection of Electro-Magnetic Emissions Transmitted from Earthquake Regions) during the 27 February 2010 M = 8.8 Chile earthquake. The nighttime electron density (N e ), electron temperature (T e ), ion density (N i ), ion temperature (T i ) and whistler counts (C w ) are investigated. A statistical analysis of the box-and-whisker method is applied to see if data of two or more groups under study are significantly different. A cross-examination of temporal variations before and after shows that N e and N i (C w ) increases (decreases) appear 10-20 days before the earthquake. A comparison of data over the epicenter and those over its reference area can be employed to discriminate the earthquake-related anomalies from global effects. Results prove that anomalous enhancements of N e , N i , and T i occur specifically around the epicenter area. The intersection of the temporal and spatial results confirms that N e and N i are useful and sensitive detecting anomalous related to the 2010 M = 8.8 Chile earthquake.

An improved coupling model for the lithosphere‐atmosphere‐ionosphere system

“…The related electromagnetic perturbations can be traced back along the magnetic field line to the region of earthquake activities [ Pulinets and Legen ' ka , ; Pulinets and Boyarchuk , ; Liu et al ., ]. These precursor phenomena include the presence of electron density fluctuations in the ionosphere above the seismic regions [ Liu et al ., ; Kakinami et al ., ; Heki , ], the change of ionic composition and temperature of plasma in the ionosphere [ He et al ., ; Oyama et al ., ; Ho et al ., ], and oscillation of the height profile of the ionospheric F region [ Afraimovich et al ., ; Astafyeva and Heki , ; Cahyadi and Heki , ].…”

Ion density and temperature variations at altitude of 500 km during moderate seismic activity

“…Enhancement in ionospheric temperatures due to seismic activity has been reported (Sharma et al, 2013;Ho et al, 2013;Sarkar et al, 2012). However, Oyama et al, (2008) used Hinotori satellite data and observed decrease in Te during pre and post seismic events.…”

“…The statistical analyses of ionospheric temperatures (Te and Ti) are comparatively less rich (Shen et al, 2015). increases as an effect of seismic activity (for example Oyama et al, 2016;Ho et al, 2013;Sarkar et al, 2012). However, these studies were conducted using DEMETER and DMSP satellite having an average altitude of 700 and 800 km respectively.…”

Recent progress in ionospheric earthquake precursor study in China: A brief review

“…After considering ionospheric variation during earlier days before the earthquake, Píša et al (2011) observed an anomalous increase of the O + ion density from DEMETER data over the epicenter area 10-20 d before the earthquake. Ho et al (2013a) further performed a cross-examination of temporal variations of electron density before and after the earthquake. The results demonstrate that the electron density increases appear 10-20 d before the earthquake.…”