Satellittgravimetri

Satellittgravimetri is a method used to measure the Earth's gravity field using satellites. By observing the orbital variations of satellites, scientists can deduce the distribution of mass on and within the Earth. These variations are caused by the gravitational pull of different regions of the planet. Satellites used in gravimetry are equipped with highly sensitive instruments, such as accelerometers and gradiometers, that can detect subtle changes in acceleration due to gravity.

The principle behind satellittgravimetri relies on Newton's law of universal gravitation. As a satellite orbits the Earth, its trajectory is influenced by the local gravity. Areas with higher mass density exert a stronger gravitational pull, causing the satellite to accelerate slightly more and its orbit to deviate from a perfect ellipse. Conversely, areas with lower mass density result in a weaker gravitational pull and a different orbital path.

Data collected from these orbital measurements are processed to create detailed maps of the Earth's gravity anomalies. These anomalies represent deviations from a perfectly smooth gravity field and are indicative of subsurface geological structures, such as sedimentary basins, mountain ranges, and mineral deposits. Satellittgravimetri plays a crucial role in various scientific disciplines. It is used in geophysics to understand the Earth's internal structure, plate tectonics, and mantle dynamics. It also contributes to oceanography by helping to map the seafloor topography and ocean currents, as variations in gravity are linked to the distribution of water mass. Furthermore, it finds applications in hydrology for monitoring groundwater resources and in the search for oil, gas, and mineral exploration.