DEBOLINA ROY
Ground deformation
Geoscientists utilize both levelling devices and Global Positioning System (GPS) technologies to detect deformities in land. The movement from rain or variation in groundwater can be of the early signs of an earthquake.
Small tremors and unusual sounds
Small earthquakes, known as foreshocks, can happen before a large quake when energy is released from the Earth's crust. The tremors may also be heard or felt as rumblings or gurgles, which are sometimes considered by seismologists.
Changes in underground water and gas
Pressure created within the earth can lead to small cracks forming in rocks. Increased amounts of the radioactive radon gas have been detected close to the surface prior to certain earthquakes.
Thermal and electromagnetic disturbances
The abnormalities include heat, electricity, and electromagnetic phenomena which can be detected using satellites and infrared detectors. Abnormalities may also affect animal activities.