Geomagnetism - 6 of 21

Geomagnetism FAQs - 21 Found

How does a compass work?

An old compass.

The needle of a compass is a small magnet that is allowed to pivot in the horizontal plane. The needle experiences a torque from the ambient magnetic field of the Earth. The reaction to this torque is the needle's preferred alignment with the horizontal component of the geomagnetic field. The "north" end of the compass needle is simply the north end of the magnet; it is the end of the compass needle that points to the north magnetic pole, in the general direction of the geographic north pole. The "south" end of the compass needle is the south end of the magnet; it points to the south magnetic pole, in the general direction of the geographic south pole. 

 

The preferred directionality of a compass can be affected by local perturbations in the magnetic field, like those set up by a nearby electrical system. A compass can also be affected by local magnetization of the Earth's crust, particularly near large igneous or volcanic rock deposits.

Tags: Geomagnetism, Magnetic Field, Monitoring, Sun, Core, Declination, Polarity