Comparison between two important events occurred in the Tonga-Kermadec subduction zone: June 15, 2019 M7.2 Kermadec Islands earthquake and January 15, 2022 Hunga Tonga-Hunga Ha`apai eruption.

One of the most active areas for the subduction continuous processes is the Tonga-Kermadec zone. Recently, two important geophysical events took place there: in 2019, an M7.2 earthquake with the epicentre in Kermadec Islands (New Zealand) and, in 2022, an unprecedented eruption of Hunga Tonga-Hunga Ha`apai (HTHH) volcano. We focused on the analysis of any effect before, during, and after each event with a multi-parametric and multi-layer approach to study the geodynamic of the entire area based on the Lithosphere-Atmosphere-Ionosphere Coupling (LAIC) models. In detail, we conducted a seismic analysis of both sequences of phenomena, culminating with the corresponding disruptive event, centring our attention in the respective Dobrovolsky area. We detected various anomalies in the atmospheric parameters like temperature, pressure and presence of gases connected to the events. Finally, Ultra Low Frequency (ULF) magnetic field changes and electron burst precipitations were observed from Low Earth Orbit (LEO) satellites above the Pacific. All these observations give us a better insight of the complex tectonic context.