Scientists have revealed that they've been able to identify a second magnetic field generated by the Earth. Scientists presented the new data at the 2018 European Geosciences Union in Vienna, Austria.
The moon is playing a role in generating this second magnetic field.
The Ocean's Magnetic Field
Researchers from the European Space Agency (ESA) used a trio of satellites called the Swarm to detect the second magnetic field. Earth's main magnetic field is created by the movement and swirling of superheated liquid iron in the outer core. Factors such as magnetized rocks in the crust and the flow of the ocean can also have an effect on the magnetic field.
Scientists discovered that this second magnetic field is created at the Moon pulls the Earth's oceans through the magnetic field. This generates an electric current which produces a magnetic signal. This field is difficult to detect because it is 20,000 times weaker than the Earth's global magnetic field.
Using the Swarm satellites, scientists were able to determine the magnetic signals of tides from the ocean surface to the seabed. Nils Olsen who worked on the survey said that this gives researchers a picture of how to the ocean flows at all depths.
Olsen adds that this may be key to understanding climate change. Olsen says that the oceans absorb heat from the air and tracking how this heat is distributed and stored at different depths.
Improved Map Of Magnetic Fields
Along with the discovery of the second magnetic field, researchers also revealed a new map of Earth's magnetic field using their findings. To make the map scientists used four years of Swarm measurements, data from a German spacecraft called Champ, and information collected by airplanes and ships.
Researchers' new map of Earth's magnetic fields shows how the planet's surface rocks are able to retain magnetism. On the map, zebra-stripes can be seen on mid-ocean ridges. These are areas where rising magma creates new seafloor and makes the magnetic field cool rock minerals.
Swarm mission manager Rune Floberghagen says that the magnetic field is key to understand what's beneath the surface of Earth.
Another aspect of the research presented by researchers was the movement of the north magnetic pole. Researchers noted that the magnetic north pole is drifting away from Canada and getting closer to Russia. They noted that this year, the magnetic north pole is only around 240 miles away from the geographic north pole.
Scientists also revealed that magnetic pole moves at a rate of about 34 miles per year.