A "dip needle" is a small magnet mounted on a horizontal axis so that it can swivel up or down. Where on Earth will a dip needle point most nearly verically? Where will it point most nearly horizontally?
To determine where a dip needle will point most nearly vertically or horizontally on Earth, we need to understand the concept of magnetic inclination or dip.
Magnetic inclination refers to the angle at which the magnetic field lines intersect with the Earth's surface. It varies depending on the location on Earth, and the dip needle aligns itself with these magnetic field lines.
To find the location where a dip needle will point most nearly vertically, we need to consider the Earth's magnetic poles. The magnetic poles are not in alignment with the geographic poles, but rather in slightly different positions. The magnetic North Pole is currently located in the Canadian Arctic, while the magnetic South Pole is near the coast of Antarctica. As a result, the dip needle will point most nearly vertically near these magnetic poles. Therefore, the closer you are to either the magnetic North or South Pole, the closer the dip needle will be to vertical.
Conversely, to determine where the dip needle will point most nearly horizontally, we need to look for locations where the magnetic field lines are parallel to the Earth's surface. These locations are called magnetic equators. Since the Earth's magnetic field is not perfectly aligned with the Earth's geographical equator, the magnetic equator is also not exactly at the same location. However, it roughly follows the geographic equator. Therefore, the dip needle will point most nearly horizontally near the magnetic equator, which is generally close to the geographic equator.
To summarize:
- The dip needle will point most nearly vertically near the magnetic North and South Poles.
- The dip needle will point most nearly horizontally near the magnetic equator, which is roughly aligned with the geographic equator.
It's important to note that the actual directions can vary depending on factors like local magnetic anomalies, but these general principles provide a good understanding of where a dip needle will point on Earth.