We propose to perform a wide spectrum of ionosphere-related research, from ionosphere seismology to ionospheric storms and GNSS/GPS performance during extreme ionospheric and space weather events. The main focus will be made on such rare subject as ionosphere seismology that aims to study ionosphere response to large earthquakes, to investigate the main properties of different kinds of ionospheric disturbances occurred due to seismic and seismic-like events, including tsunamis, volcano eruptions and explosions. The 11/03/2011 Tohoku megaquake has opened new challenges for modeling of co-seismic effects and has indicated new directions for further research. In particular, we found that the ionosphere is able of showing images of a seismic fault slip rupturing about ~8 minutes after an earthquake, which opens new opportunities for short-time tsunami warnings.In addition to the ionosphere seismology, the project includes fundamental multi-instrumental studies of the global dynamics of the ionosphere under geomagnetically disturbed and quiet conditions. Great attention will be paid on investigation of features of traveling ionospheric disturbances and on the ionosphere behavior during variations of interplanetary parameters such as magnetic field (IMF) and electric field (IEF). The latter is directly connected to the last subject of our proposal - solar- and ionosphere-induced GPS -failures.The main advantages for Europe coming with this project are: 1) a highly interdisciplinary project on a sufficiently new branch of the science and with rare applications; 2) extension of the fundamental ionosphere studies in Europe that will increase the competitiveness of Europe among other world-famous research schools on the Earth’s ionosphere; 3) the results of our work on GNSS operation quality will be useful for the future Galileo mission as well, and would help to improve the system.