What is approximately equal to the induction of the Earth’s magnetic field? Give an example showing that the magnetic

What is approximately equal to the induction of the Earth’s magnetic field? Give an example showing that the magnetic induction at the Earth’s surface is not the same.

It is known that at the Earth’s surface the magnetic field induction is approximately 10 ~ 4 T, which is approximately 100 times less than the magnetic field induction of a strip magnet (near the poles). There are deposits of iron ore in the earth’s crust in some places. In these places, the induction of the Earth’s magnetic field increases. In Russia, such an area is the iron ore basin within the Kursk, Belgorod and Oryol regions, called the Kursk magnetic anomaly.