Due to the Coriolis Force (as a consequence of the earth's rotation)
If only allowed to pivot in a horizontal plane, it would wander aimlessly. If also allowed to deflect vertically, it would point straight down into the ground.
The Coriolis Effect
The indo-australasian or the African plates are moving north
During April, the sun is moving from south to north, heading north.
If you are moving away from the North Pole and crossing lines of Latitude, you are heading for the Equator, and ultimately the South Pole.
If only allowed to pivot in a horizontal plane, it would wander aimlessly. If also allowed to deflect vertically, it would point straight down into the ground.
The Coriolis Effect
If you are North of the equator.....If you travel north, latitude increases,If you travel south, latitude decreases.If you are South of the equator.....If you travel north, latitude decreases,If you travel south, latitude increases.
That is because the Earth is rotating. The coriolis effect puts a spin on the moving air. The following video is about storms, but the principle is explained.
The indo-australasian or the African plates are moving north
Exactly straight over the equator. It's a tiny bit north of the equator just before the Autumnal Equinox, and a tiny bit south of the equator just after it. In other words, the sun is 'moving' south. At the Vernal Equinox, it's also precisely over the equator, but 'moving' north.
The Bering Straight
Due north is straight north, or exactly north.
Closer
a bearing is the angle from north moving clockwise 360 degrees a negative bearing is moving counterclockwise from north
the Coriolis force, which is produced by earth's rotation.
The geographical North Pole is not moving. The magnetic north pole is constantly moving because of the shifts in the Earth's magnetic field. Currently, it is moving towards Russia at a rate of 64km a year, or almost 40 miles a year. See the related link.