Maximum electron concentration and total electron content of the ionosphere over Concepción, Chile, prior to the 27 February 2010 earthquake

Analysis of Ionospheric Vertical Total Electron Content before the 2014 Mw8.2 Chile Earthquake

“…Although there are many papers reporting the identification of ionospheric anomalies before earthquakes, it remains controversial whether these anomalies are actually related to forthcoming earthquakes [12][13][14][15][16]. There was no statistically significant correlation between TEC anomalies and earthquakes in Southern California from 2003 to 2004 [13].…”

“…Masci suggested that the statistical analysis of Kon et al was not reliable because it was influenced by global geomagnetic events [14,17]. Ovalle et al concluded that the observed NmF2 and TEC anomalies could not be unambiguously related to the 2010 M8.8 Chile earthquake [15]. To validate the relationship between ionospheric anomalies and earthquakes in response to the controversy, several studies have been undertaken to be expected to obtain more credible results.…”

Ionospheric characteristics prior to the greatest earthquake in recorded history

“…The analysis can be considered as a follow up to the one reported by Foppiano et al (2008), which discussed only the critical frequency of the F-region, but using the methodology of Ovalle et al (2013). The main purpose is again to show whether ionospheric precursors proposed on various statistical studies are consistent with the ones that could be derived for these great Chilean May 1960 earthquakes.…”

“…For a consolidated review of this type of statistical analyses see Pulinets and Boyarchuk (2004). Later references are given by Ovalle et al (2013) who discuss total electron concentration (TEC) and maximum electron concentration (NmF2) anomalies for the Chilean 27 February 2010 earthquake. Obviously, a key point in determining anomalies is whether it is possible to screen tropospheric/stratospheric variability that reaches the ionosphere (Forbes et al, 2000;Mendillo et al, 2002;Lȃstovička, 2006) from the observed ionospheric variability so as to identify likely precursor ionospheric signatures.…”

Ant Colony Optimization detects anomalous aerosol variations associated with the Chile earthquake of 27 February 2010

“…Zhang et al (2011) compared the temporal and spatial distributions of electron density and temperature with that of electric field, which proved the existence of irregularities above Chile epicenter 2 and 3 days before and 1 and 2 days after the event. Ovalle et al (2013) analyze the observations of the maximum electron concentration (NmF2) over Concepció n (36.8°S; 73.0°W) and of the Total Electron Content (TEC) for an area covering the rupture zone corresponding to the very large Chile earthquake of 27 February 2010.…”