True North refers to the geographic North Pole, which is the point on Earth where the planet’s axis of rotation intersects the surface in the Northern Hemisphere. It is the direction along the Earth’s surface that points towards the geographic North Pole, and it is used as the reference point for all true directions and coordinates in navigation and mapping.
Key Points about True North:
- Geographic North Pole:
- True North is the direction toward the Geographic North Pole—the fixed point located at 90° North latitude. This is different from magnetic north, which refers to the direction that a magnetic compass points (and can shift over time due to changes in Earth’s magnetic field).
- Fixed Reference:
- True North is a fixed direction, meaning it does not change over time or location, unlike magnetic north, which can vary due to the Earth’s shifting magnetic fields.
- It is used in geographic coordinates, such as those in maps, GPS, and navigation charts.
- True North vs. Magnetic North:
- True North is aligned with the Earth’s rotational axis, and it is considered the universal reference for all geographic navigation.
- Magnetic North, on the other hand, is the direction that a magnetic compass points, which is influenced by Earth’s magnetic field. The difference between True North and Magnetic North is called magnetic declination or variation. Depending on where you are on Earth, this difference can range from a few degrees to over 20 degrees.
- Navigational Importance:
- When navigating using maps, charts, or GPS systems, True North is often used to calculate true bearings and course headings. This is important for precise navigation over long distances, especially in aviation and maritime contexts.
- Global Positioning Systems (GPS):
- Modern GPS systems use True North as the reference for determining position and providing accurate navigation data.
Example of True North in Navigation:
- When using a map with True North indicated (often at the top), navigators can measure angles from the map’s orientation (aligned to True North) to find the direction to travel.
- If you are given a true bearing of 90°, you would head directly east (in relation to the True North direction) to reach your destination.
In contrast, magnetic compasses will point toward Magnetic North, and navigators must adjust for the magnetic variation between True North and Magnetic North to maintain an accurate course.
In summary, True North is the fixed, geographic direction towards the Earth’s North Pole, and it serves as the standard reference for all geographic coordinates and directions in navigation.
