# Successful Tests on Detecting Pre-Earthquake Magnetic Field Signals from Space  
[PERSON]  
1 Institute of Geophysics, University of Tehran, Tehran 14155-6619, Iran; [EMAIL_ADDRESS] (H.A. ); [EMAIL_ADDRESS] (H.R.) [PERSON]  
1 Institute of Geophysics, University of Tehran, Tehran 14155-6619, Iran; [EMAIL_ADDRESS] (H.A. ); [EMAIL_ADDRESS] (H.R.) [PERSON]  
2 Istituto Nazionale di Geofisica e Vulcanologia (INGV), 00143 Rome, Italy  
ground [5; 6; 7; 8; 9; 10] and satellite data [11; 12; 13]. Satellites specifically designed for magnetic field measurements, such as CHAMP and Swarm, have been instrumental in observing electromagnetic phenomena likely associated with earthquakes [14; 15]. Magnetic field anomalies have been linked to changes in rock properties due to stress, and their detection has been reported before major earthquakes [16; 17]. The term \"earthquake precursor\" encompasses a range of physical phenomena that occur prior to certain earthquakes and are expected to be physically related to their preparation. Various precursors, such as electric and magnetic fields, changes in water levels, gas emissions, temperature fluctuations, surface alterations, and seismic patterns, have been identified [9; 10; 18; 19; 20; 21]. However, not all precursors manifest in every earthquake, posing challenges to their reliability. Researchers from different disciplines have contributed to identifying and understanding these phenomena, but issues of reproducibility and verification still remain. Magnetic field changes have emerged as significant earthquake precursors, and advancements in remote sensing and satellite technology have furthered their study. Early works in the 1960s explored electromagnetic signals associated with seismic events, and subsequent studies confirmed distinct magnetic field anomalies related to earthquakes [6; 22; 23; 24]. Both ground and satellite data have been analyzed to detect magnetic anomalies potentially caused by seismic events. Laboratory and field trials have supported the connection between seismic events and magnetic field changes, attributed to variations in rock properties [25; 26]. Satellite data, including observations from missions like DEMETER, CHAMP, and Swarm, have contributed to the identification of magnetic anomalies preceding earthquakes [14; 15; 16]. Models have been proposed to explain the interconnectedness of the lithosphere, atmosphere, and ionosphere during earthquake preparation. These models suggest processes such as ionization of the atmosphere by positive holes released from the fault surface or the release of gases, like radon, from the lithosphere [19; 27; 28; 29]. These processes trigger a chain of interactions that extend from the lithosphere to the atmosphere and eventually the ionosphere. Earthquakes are not randomly distributed but tend to occur along specific belts worldwide. The Alpine-Himalayan belt, the focus of this research, extends for more than 12,000 km from southern Europe to eastern Asia and experiences significant seismic activity, the most intense on the planet, after that of the Pacific Ring of Fire. It is the result of plate collisions, such as the African-Sinai-Arabian plate with the Eurasian Plate in the west and the collision of the Indian continent with Eurasia in the east. The Eurasian Plate, which includes Europe and a large part of Asia, is moving southward. The African Plate is moving northward, pushing against the Eurasian Plate. The Indian Plate is moving northward and colliding with the Eurasian Plate. This belt encompasses several major continental plates, as mentioned, as well as internal seas with oceanic crust. The collision of the African Plate with the Eurasian Plate has caused compression and folding of the Earth's crust, leading to the formation of the Alps in Europe. Similarly, the collision of the Indian Plate with the Eurasian Plate has resulted in the formation of the Himalayas, the highest mountain range in the world.