Combining Swarm Langmuir probe observations, LEO-POD-based and ground-based GNSS receivers and ionosondes for prompt detection of ionospheric earthquake and tsunami signatures: case study of 2015 Chile-Illapel event

The study investigates ionospheric electric field responses to the earthquake (EQ) of magnitude 8.3, and related seismic activity tsunami triggered by mainshock in Chile-Illapel region, at 22:54 UTC, evening September 16, 2015. work is a wider review available ground satellite data techniques detect seismically induced traveling disturbances (TID) irregularities smaller scale. used experiment includes several types observations from low-Earth orbit (LEO) satellites. number applied here also extended spectral analysis LEO along-track composed GNSS data. timeframe analyses focused on 16 17, 2015 but adjacent days, where an enhanced has been recorded. Several examples TIDs are shown, as detected combined more than one source applying different methods, including analysis. These occur before mainshock, just after, or time following this large EQ, can be found close neighborhood far away epicenter. objective was demonstrate increasing techniques, which limited when alone, their combination provide many advantages disturbed ionosphere. reaching all regions globe with local dense ground-based HF sounders looks promising, especially view nearby availability CubeSat constellations equipped instruments for ionosphere sounding. An important conclusion coming need processing requirement validation separate A general key finding refers complementarities field, critically case analyzing ionosphere, if not every sounding direction successfully find it.