MadSci Network: Earth Sciences |
Greetings from South of the equator. Have a good look at your compass. The needle has two ends. Typically one is coloured red, and the other one silver. The red end is what points to the North (Magnetic) Pole, and the silver end therefore points to the South Magnetic Pole. That is what happens in the Southern Hemisphere as well. If you have a good quality compass, there is one important difference. In the Northern hemisphere, the Northern (red) end of the compass needle wants to dip downward. The dip is stronger the further North you go. Compass makers compensate for this by putting extra weight on the southern end of the compass needle or card. They even make different compasses with different amounts of compensating weight for Canada and Florida. But here in Australia, the Southern end of the compass needle is what wants to dip downward, and the needle or card must be weighted at the other end. If I bring a good compass here from Europe or North America it is almost unusable because the North end wants to point up into the sky! The southern side of the card is weighted heavier anyway, because it was designed for use in the Northern hemisphere, and then the Earth's magnetic field makes it want to dip even more.
Try the links in the MadSci Library for more information on Earth Sciences.