Main phenomenological features of ionospheric precursors of strong earthquakes

Пулинец, С. А.; Legen’ka, A. D.; Gaivoronskaya, T. V.; Depuev, V.

doi:10.1016/j.jastp.2003.07.011

Cited by 251 publications

(168 citation statements)

References 14 publications

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“…2; it should be pointed out that the day 5 and day 6 values correspond to the ionospheric disturbances over Lhasa station, about 1000 km from the epicenter, not shown) over Chongqing station, near the epicenter, were observed under quiet geomagnetic conditions, while there was an unobvious disturbance in f oF2 over Urumuqi station. The localization is possibly one of the most important signatures related to seismic activity, in contrast to global-scale disturbances triggered by geomagnetic storms (Pulinets et al, 2003;Zhao et al, 2008). This distinct feature was also observed in TEC extracted from global ionospheric maps (GIMs) before the moderate M = 4.7 2010 Chongqing earthquake (with a very shallow depth of 7 km, www.ann-geophys.net/33/687/2015/ Ann.…”

Section: Annmentioning

confidence: 82%

“…Statistical analysis has shown that the earthquake-induced ionospheric anomalies versus LT are most frequent in the afternoon LT sector, approximately 12:00-18:00 LT (Pulinets et al, 1998b;Liu et al, 2006;Sharma et al, 2010). Pulinets et al (2003) showed that the ionospheric deviations in f oF2 were positive or negative depending on the position of the ionosonde in relation to the anomaly formed in the ionosphere. However, Le et al (2011) found that the occurrence rate of abnormal increase was much higher than that of abnormal decrease.…”

Section: Local Time Variation In the Ionosphere Related To Earthquakesmentioning

confidence: 99%

“…Figure 2 shows the days of ionospheric anomalies prior to the main shocks, i.e., a higher occurrence during the several days before earthquakes, which is consistent with the conclusions drawn by many authors (Pulients, 2003;Liu et al, 2004Liu et al, , 2006Le et al, 2011;etc). However, by analyzing 11 earthquakes in 2003-2005, Dabas (2007 claimed that the ionospheric anomalies occurred 2 to 25 days prior to the earthquakes. Figure 3 illustrates the occurrence of ionospheric abnormal increase in f oF2 versus LT, from which one can see that though the positive disturbances were sometimes present at nighttime, the disturbances predominately occurred during the afternoon period.…”

Section: Local Time Variation In the Ionosphere Related To Earthquakesmentioning

confidence: 99%

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Is there any difference in local time variation in ionospheric F2-layer disturbances between earthquake-induced and Q-disturbance events?

Wang

et al. 2015

Ann. Geophys.

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Abstract. Ionospheric anomalies before earthquakes have become the subject of one of the most intensive studies in the area of ionospheric variation. The ionosphere has a large class of disturbances under quiet geomagnetic conditions, i.e., quiet time disturbances (Q disturbances). Hence, the characteristics of seismo-ionospheric anomalies obtained by statistical analysis should be compared with those of Qdisturbance events. Using the data of f oF2 (F2-layer critical frequency) during the whole interval of 1978-2008 ( ∼ 3 solar cycles), the local time (LT) variation in Q disturbances is investigated. The results showed that a well-pronounced nighttime peak took place for positive disturbances induced by Q-disturbance events, while positive disturbances related to earthquakes predominately occurred in the daytime, especially in the afternoon LT sector. This remarkable difference in local time variation in f oF2 between the earthquaketriggered and Q-disturbance events is of great significance for the identification of ionospheric precursors.

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Section: Annmentioning

confidence: 82%

Section: Local Time Variation In the Ionosphere Related To Earthquakesmentioning

confidence: 99%

Section: Local Time Variation In the Ionosphere Related To Earthquakesmentioning

confidence: 99%

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Is there any difference in local time variation in ionospheric F2-layer disturbances between earthquake-induced and Q-disturbance events?

Wang

et al. 2015

Ann. Geophys.

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“…TEC is the total number of electrons along the vertical path between the satellite and the ground in 1 m 2 cross section column; TEC is measured in TEC units (1 TECU = 10 16 el/m 2 ) (Mannucci et al 1993;Langley 1996). Many researchers have reported that large seismic activities can be revealed through the unexpected variation in GPS-based TEC of ionosphere (Zaslavski et al 1998;Liu et al 2001;Pulinets et al 2003;Zakharenkova et al 2007;Zakharenkova et al 2008;Namgaladze et al 2009;Karia & Pathak 2011;He et al 2012). The GPS TEC of the ionosphere is mainly controlled by the intensities of solar electromagnetic radiation.…”

Section: Introductionmentioning

confidence: 99%

Removal of solar radiation effect based on nonlinear data processing technique for Seismo-Ionospheric Anomaly before few earthquakes

Yadav

Karia

Pathak

2015

Geomatics, Natural Hazards and Risk

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The study of ionospheric precursorsof earthquakehas gained interest among many researchers, specially the precursor obtained in terms of anomalous variation in total electron content (TEC). If earthquake occurs during a period of moderate to high solar activity, the TEC derived using global positioning system (GPS) measurements requires the elimination of solar effect so as to identify the precursory signature. This paperincludes multi-resolution time series technique to remove the nonlinear effect from solar radiation on GPS-based TEC. The technique is based on wavelet transform applicable to RINEX TEC data. This technique is used to remove nonlinear background solar effect from TEC prior to four different earthquakes (M > 6.0). Further in order to evaluate the extracted TEC, we obtain the correlation between the decomposed TEC A6 and measured solar index (F10.7) and extreme ultraviolet (EUV). A good correlation is obtained between decomposed TEC A6 and EUV for all the cases. This suggests that this technique is useful in removal of background solar effect for identifying earthquake precursor in TEC.

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“…The main phenomenological features of ionospheric precursors of strong earthquakes are summarized by Pulinets et al (2003). Various experimental and mathematical models clearly indicate lithosphere-ionosphere coupling within or far from the area of the earthquake preparation zone (Karia and Pathak 2010).…”

Section: Introductionmentioning

confidence: 99%

Changes in total electron content associated with earthquakes (M > 5) observed from GPS station, Varanasi, India

Priyadarshi

Kumar

Singh

2011

Geomatics, Natural Hazards and Risk

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The total electron content (TEC) derived from the global positioning system (GPS) at Varanasi (latitude 25.38 N, longitude 82.998 E), India has been measured during 2007 and 2010. We have chosen nine earthquakes (M 4 5) that occurred within 2000 km of Varanasi during 2007 and 2010 to study the changes in TEC associated with these earthquakes. A monthly median (MM) of the TEC and associated inter quartile range (IQR), upper bound (UB) and lower bound (LB) are utilized as a reference for identifying abnormal signals during all nine earthquakes. The results show anomalous reductions and enhancements in the TEC. These pre-earthquake ionospheric anomalies appear within 5 days prior to earthquakes. A possible mechanism responsible for ionospheric anomalies associated with earthquakes is discussed.

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Main phenomenological features of ionospheric precursors of strong earthquakes

Cited by 251 publications

References 14 publications

Is there any difference in local time variation in ionospheric F2-layer disturbances between earthquake-induced and Q-disturbance events?

Is there any difference in local time variation in ionospheric F2-layer disturbances between earthquake-induced and Q-disturbance events?

Removal of solar radiation effect based on nonlinear data processing technique for Seismo-Ionospheric Anomaly before few earthquakes

Changes in total electron content associated with earthquakes (M > 5) observed from GPS station, Varanasi, India

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