Ionospheric response to earthquakes of different magnitudes: Larger quakes perturb the ionosphere stronger and longer

Abstract

[1] Recently, it has been shown that the ionosphere is capable of showing images of seismic fault shortly after an earthquake. This gives rise to the idea of retrieval of seismic information from ionospheric observations. As the first step toward such inversion, here we study distinctive features of ionospheric response to shallow earthquakes, both submarine and inland, of moment magnitudes Mw7.2-9.1. Using GPS measurements of the ionospheric total electron content, we show that: (1) the amplitude of coseismic total electron content variations in the near-field is larger after more powerful earthquakes, and (2) stronger earthquakes (M > 7.9) are in general characterized by a longer negative phase in coseismic perturbations. Citation: Astafyeva, E., S. Shalimov, E. Olshanskaya, and P. Lognonné (2013), Ionospheric response to earthquakes of different magnitudes: Larger quakes perturb the ionosphere stronger and longer, Geophys.

Coseismic ionospheric disturbance of the large strike-slip earthquakes in North Sumatra in 2012: Mw dependence of the disturbance amplitudes

“…A1). It has the magnitude close to the threshold suggested by Perevalova et al (2014) (Astafyeva et al 2013). Other examples are newly analysed in this study.…”

“…A larger earthquake causes larger crustal deformation and a larger CID (Astafyeva et al 2013). If we know the relationship between them, we could infer earthquake magnitudes from CID amplitudes immediately after acoustic waves arrived at the F region, as early as ∼7-8 min after the earthquake .…”

“…The 2012 North Sumatra earthquake was the largest strike-slip earthquakes ever recorded, and it is a good opportunity to discuss this point. Astafyeva et al (2013) also compiled 11 earthquakes with clear CID observations, and investigated the correlation between M w and CID amplitudes. The three distinct differences of our study from Astafyeva et al (2013) is that (1) we discuss all the three mechanism earthquake while they discussed only thrust (low-angle reverse) earthquakes, (2) number of earthquakes discussed is nearly twofold and (3) we discuss CID amplitude relative to background vertical TEC while they discussed amplitudes of absolute TEC changes.…”

On a reported effect in ionospheric TEC around the time of the 6 April 2009 L'Aquila earthquake

“…The amplitude and duration of a CID mainly depend on the earthquake magnitude (Astafyeva et al, 2013;Cahyadi and Heki, 2015). In contrast, although there are several published papers that report ionospheric changes preceding large earthquakes (see e.g.…”

“…All this makes it difficult to identify possible earthquake-related effects in the ionosphere (see e.g. Afraimovich and Astafyeva, 2008;Astafyeva and Heki, 2011) and may lead researchers to a misinterpretation of the obtained results (see e.g. Masci, 2012a.…”