It decreases and becomes zero at the poles.
Explanation
Meridians of longitude are imaginary semi-circular lines running vertically from the North Pole to the South Pole. Unlike parallels of latitude, which are parallel circles, meridians converge as they approach the geographic poles.
Detailed Analysis
- Maximum Distance at the Equator: The distance between any two meridians is greatest at the Equator (0° latitude), measuring approximately 111.3 kilometers (69 miles).
- Convergence Towards Poles: As one moves from the Equator towards the poles (either North or South), the circumference of the parallels of latitude decreases. Consequently, the meridians draw closer together.
- Zero Distance at Poles: At the North Pole (90° N) and the South Pole (90° S), all meridians intersect at a single point. Therefore, the linear distance between them reduces to zero.
Key Takeaway
Meridians of longitude are not parallel lines; they are widest apart at the Equator and converge to meet at the poles, where the distance between them becomes zero.