Changes in Gravity
The superconducting gravimeter GWRT020 at Metsähovi observes temporal variations in gravity, smaller than 10-12 microgal. The main goal is the maintenance of the equipment, continuous data acquisition and good quality. The data of gravimeter have been transmitted to the GGP (Global Geodynamic Project) respectively data from other global stations (20) are available. Due to high precision, the data has been applied all-round to investigations at Metsähovi. Main topics are Earth tides, local hydrological effects on gravity (rain, snow and groundwater) and loading effects. The atmosphere and Baltic Sea level cause gravity changes and vertical motion. The gravity data is compared to results of gravity satellites (CHAMP and GRACE). The gravimeter has been used as a long-periodic seismometer to study free oscillations of the Earth after major earthquakes.