![]() We coupled the VADASE and VARION algorithms-the former being able to estimate surface waveforms and co seismic displacements 41, 42, and the latter is able to compute sTEC perturbations in real-time 29, 30. We introduce here the dual GNSS real-time contribution using the same data-stream from permanent stations for both ground shaking and TEC estimation, to explore the potential improvement of tsunami genesis estimation. 42 to estimate seismic waveforms and coseismic displacements. Also in this case, the real-time approach, named VADASE (Variometric Approach for Displacements Analysis Stand-Alond Engine), was proposed by Colosimo et al. Ground motion measured by GNSS receivers has been used to estimate the magnitude 37, moment tensor 38 as well as finite source 39, in particular for tsunamigenic events and to improve the tsunami genesis estimation 40. A great effort in the last decade has been done in order to explore the contribution of GNSS data in the future tsunami warning systems in order to improve their reliability of the responses. The ground motion measured by GNSS is benefiting of its relevant feature not to be affected by the saturation problem, which can impact seismometers located near the epicenters of strong earthquakes. ![]() ![]() On the other hand, it has been known and tested that earthquakes induced ground shaking and coseismic displacements that can be effectively recorded using GNSS as well 31, 32, 33, 34, 35, 36. They introduced the ionospheric tsunami power index (ITPI) empirically related to the maximum volume of displaced water (in km 3) during the tsunami genesis to discriminate tsunamigenic earthquakes. Authors highlighted the potential use of GNSS-sTEC observations for tsunami genesis estimation at 8 min after the rupture to support conventional tsunami warning systems. 16 clearly shows the empirical relationship between the TEC perturbations and the maximum volume of the displaced water during the tsunami genesis (source extent times the max uplift at the source). In particular, at the epicentral area, the uplift at the surface-produced by the seismic rupture-induces, by dynamic coupling with the atmosphere, an acoustic-gravity wave (AGW \(_\) to be detectable by GNSS-sTEC observations. Natural hazards such as earthquakes and the subsequent tsunamis generate atmospheric acoustic-gravity waves that propagate upward to the ionosphere where they may be detectable by ionospheric sounding techniques 1. The GNSS data stream by TVA of both the ground and ionospheric measurement opens today new perspectives to real-time warning systems for tsunami genesis estimation. ![]() The high spatial resolution of ionospheric TEC measurement seems to match with the extent of the seismic source. Nominally, we also highlight a stronger kinetic energy released in the north of the epicenter and visible in both, the ground motion and the TEC perturbation detect at 30 s and around 9.5 min after the rupture respectively. ![]() We apply the TVA to the Mw 8.3 Illapel earthquake, that occurred in Chile on September 16, 2015, and we demonstrate the coherence of the earthquake ground shaking and the TEC perturbation by using the same GNSS data stream in a real-time scenario. Our TVA couples together the Variometric Approach for Displacement Analysis Stand-alone Engine (VADASE) with the Variometric Approach for Real-Time Ionosphere Observation (VARION) algorithms. The aim of this work is to combine these two observations in one real-time method based on the Total Variometric Approach (TVA) to include the GNSS real-time data stream in future warning systems and tsunami genesis estimation observing both, ground motion and TEC. Global Navigation Satellite System (GNSS) is used in seismology to study the ground displacements as well as to monitor the ionospheric total electron content (TEC) perturbations following seismic events. ![]()
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