<p><strong>Abstract.</strong> 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 <i>M</i> = 8.8 Chile earthquake. The nighttime electron density (<i>N</i>_e), electron temperature (<i>T</i>_e), ion density (<i>N</i>_i), ion temperature (<i>T</i>_i) and whistler counts (<i>C</i>_w) are investigated. A

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... 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 <i>N</i>_e and <i>N</i>_i (<i>C</i>_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 <i>N</i>_e, <i>N</i>_i, and <i>T</i>_i occur specifically around the epicenter area. The intersection of the temporal and spatial results confirms that <i>N</i>_e and <i>N</i>_i are useful and sensitive detecting anomalous related to the 2010 <i>M</i> = 8.8 Chile earthquake.</p>