ESA's Swarm satellite is uncovering the very fine details of one of the most difficult layers of the earth's magnetic field. The main purpose behind this is to explore the planet's magnetic history imprinted on earth's crust.
According to ESA, the earth's magnetic field can be compared to a big coconut, which is protecting us from charged particle and cosmic radiation that bombard planet in the solar wind. Without this life would not have been existed in this way.
It is said that most of the magnetic field is created at a depth greater than 3000 km by the movement of molten iron in the outer core of the earth. The rest remaining 6% is partly due to electrical currents in space surrounding earth and partly due to the magnetised rocks in the upper lithosphere. The Lithosphere is the outer part of the earth consisting of the crust and upper mantle.
According to phys, Lithosphere's magnetic field is very weak and is, therefore, difficult to detect from space. Thus swarm trio was able to successfully map its magnetic signals. After continuously for three years of collecting data, the highest resolution map of this field from space has been released.
The success in extracting the tiny magnetic signals of crustal magnetisation was possible by combining Swarm measurements with historical data from the German CHAMP satellite and with the use of new techniques.
"Understanding the crust of our planet is not an easy job. We can't simply drill through it and measure its structure, history or composition," Rune Floverghagen from ESA's Swarm mission manager added. The measurements from space have a great value as they give a sharp global view of the magnetic structure of our planet's rigid outer shell.
Ina meeting in Canada, the new map shows the detailed variations in this magnetic field than previous satellite-based reconstruction, which was caused by geological structures in earth's crust. Thus new map defines magnetic field features down about 250 km and will also help in investigating the geology and temperatures of earth's lithosphere.
