Question

Is the earth's magnetic field weakening?

Answer 1

Earth is a powerful natural magnet and its magnetic field is present everywhere on the earth’s surface. The earth’s magnetic field at a particular place can be completely described by the three parameters, namely, magnetic declination, angle of dip or magnetic inclination, and the horizontal component of the earth’s magnetic field.

Complete answer:
The following is the relation between the magnetic field and the angle of inclination of the angle of dip.
$\Rightarrow B(horizontal) = B\cos \delta$
And
$\Rightarrow B(vertical) = B\sin \delta$
Here, $B$ is the magnetic field, $\delta$is the angle of dip, which is the angle between the total magnetic field of the earth and the horizontal direction.
The earth’s magnetic field changes its magnitude and direction at different places.
The earth’s magnetic field is changing throughout its existence. The forces in the core of the earth and the tilt of the magnetic axis combinedly form the area of weaker magnetic strength by allowing the charged particles inside the earth to dip closer to the surface.

Note:
Earth has two axes, a geographic axis, and a magnetic axis. The line passing through the geographical north and south poles of earth is called the geographic axis, this is also the axis of rotation of the earth. The magnetic axis is the straight line passing through the magnetic north and south poles of the earth.
The magnetic pole is in the direction of the geographic north pole and the magnetic north pole is in the direction of the geographic south pole.
The angle between the magnetic axis and the geographic axis is ${20^o}C$.