Special case of ionospheric day-to-day variability associated with earthquake preparation

On the reported ionospheric precursor of the 1999 Hector Mine, California earthquake

“…[8] It is important to recognize that we are able to reproduce the main TEC time series results of Pulinets et al [2007] over the limited duration of time that they considered (the month of October). Figure 1b shows the 10-min DTEC time series (red curve) for stations in the southwest US, along with the 1-day running average DTEC (black curve), centered on the time of the Hector Mine earthquake.…”

“…Karakelian et al [2002] found no association between ultra low-frequency (ULF, 0.01 -10 Hz) electromagnetic fields and aftershock activity. Dautermann et al [2007] found no statistically significant correlation, temporally or spatially, between TEC perturbations and 79 earthquakes in Southern California during 2004-2005. [4] Despite these contradictory results, the work of Pulinets et al [2007] remains influential in the subject of earthquake prediction. It and other similar reports have, for example, motivated (1) the development of physical theories to explain precursory processes [Freund et al, 2009;Pulinets, 2009], (2) the study of other earthquakes for similar precursory signals [Liu et al, 2009;Pulinets and Tsybulya, 2010;Pulinets et al, 2011;Heki, 2011], and (3) coordinated ground and space-based measurements for possible earthquake precursors [Bhattacharya et al, 2009;Pulinets, 2009].…”

“…It and other similar reports have, for example, motivated (1) the development of physical theories to explain precursory processes [Freund et al, 2009;Pulinets, 2009], (2) the study of other earthquakes for similar precursory signals [Liu et al, 2009;Pulinets and Tsybulya, 2010;Pulinets et al, 2011;Heki, 2011], and (3) coordinated ground and space-based measurements for possible earthquake precursors [Bhattacharya et al, 2009;Pulinets, 2009]. In recognition of the importance of earthquake prediction, we choose to examine the results of Pulinets et al [2007]. Our approach is similar to that used by Thomas et al [2009aThomas et al [ , 2009b and Masci [2010Masci [ , 2011aMasci [ , 2011b in their examinations of reported electromagnetic earthquake precursors.…”

“…Using Global Positioning System (GPS) data, Pulinets et al [2007] and Pulinets [2007] reported anomalous changes in ionospheric total electron content (TEC) starting about one week prior to the earthquake. They reported that the identified anomaly is distinct from normal TEC variation driven by solar-terrestrial interaction and TEC signals that are known to follow after an earthquake [e.g., Calais and Minster, 1995;Otsuka et al, 2006].…”

“…[1] Using Global Positioning System (GPS) data from sites near the 16 Oct. 1999 Hector Mine, California earthquake, Pulinets et al (2007) identified anomalous changes in the ionospheric total electron content (TEC) starting one week prior to the earthquake. Pulinets (2007) suggested that precursory phenomena of this type could be useful for predicting earthquakes.…”