Tug between magnetic blobs

Unlike our geographic north pole, which is in a fixed location, magnetic north wanders. This has been known since it was first measured in 1831, and subsequently mapped drifting slowly from the Canadian Arctic towards Siberia. However, since the 1990s, this drift has turned into more of a sprint – going from its historic wandering of 0–15 km a year to its present speed of 50–60 km a year. Using satellite data, including from ESA's Swarm mission, have concluded that this is down to competition between two magnetic blobs on the edge of the Earth's outer core. Changes in the flow of molten material in the planet's interior have altered the strength of the above regions of negative magnetic flux. The image shows how the strength of the magnetic patch over Canada has weakened and how the position of the north magnetic pole has changed between 1999 and 2019.

Read full story: Magnetic north and the elongating blob