Brief communication "Further comments on the ionospheric precursor of the 1999 Hector Mine earthquake"

Abstract

Abstract. Pulinets et al. (2007) document anomalous changes in the ionospheric total electron content (TEC) starting one week before the 16 October 1999 Hector Mine earthquake. The authors maintain that this TEC anomalous change is a precursor of the subsequent earthquake. In a previous paper, Afraimovich et al. (2004) excluded that TEC variations, which occurred before the Hector Mine earthquake, were induced by the preparation process of the seismic event. Thomas et al. (2012) reach similar conclusions by performing new analyses of the same TEC data which were investigated by Pulinets et al. (2007). They show that the TEC changes documented by Pulinets et al. (2007) are not anomalous but normal variations on global scale, and, therefore, these changes are not related to the localised seismic activity of the Hector Mine area. This paper confirms the results of Afraimovich et al. (2004) and Thomas et al. (2012). Through the use of geomagnetic indices time series it is shown that the presumed precursor of Pulinets et al. (2007) was a normal TEC variation induced by solar-terrestrial interaction.

Comment on “Temporal and spatial precursors in ionospheric total electron content of the 16 October 1999 Mw 7.1 Hector Mine earthquake” by Su et al. (2013)

“…They concluded that the TEC changes were part of global‐scale variations driven by solar‐terrestrial interaction, and, therefore, not related to the localized seismic activity of the Hector Mine region. In a recent report, Masci [] confirmed the findings of Afraimovich et al . [] and Thomas et al .…”

“…[] and criticized their results. However, the authors did not reference the study of Masci [] that confirmed the conclusion of Thomas et al . [].…”

“…By comparing the regional variability index of Pulinets et al . [] with geomagnetic Kp and Dst indices, Masci [] demonstrated that the reported Hector Mine earthquake precursor were normal variations controlled by geomagnetic activity [see Masci , , Figure 1].…”

Reply to comment by F. Masci and J. N. Thomas on “Temporal and spatial precursors in ionospheric total electron content of the 16 October 1999 Mw7.1 Hector Mine earthquake”

“…Comment 1: “The authors [ Su et al ., ] did not reference the study of Masci [] that confirmed the conclusion of Thomas et al . [].…”

Review Article: On the relation between the seismic activity and the Hurst exponent of the geomagnetic field at the time of the 2000 Izu swarm

“…Among these methods are magnetic polarization ratio (see Thomas et al, 2009b;Masci, 2011aMasci, , 2012a, fractal characteristics of the geomagnetic field components (see Masci, 2010Masci, , 2013aMasci and Thomas, 2013), and eigenvalues of the principal component analysis (see Masci, 2011b). Reports of ionospheric earthquake-related disturbances were also investigated (see Masci, 2012dMasci, , 2013bThomas et al, 2012). Bearing in mind these findings, the reliability of earthquake precursory signals must be carefully investigated by means of independent data.…”