In surveying, what term describes the concept where lines of longitude converge at the poles?

The term that describes the concept where lines of longitude converge at the poles is known as the convergence of meridians. This phenomenon occurs because lines of longitude, which run from the North Pole to the South Pole, are not parallel; instead, they gradually move closer together as they approach the poles.

At the equator, the distance between lines of longitude is at its maximum, but as one moves north or south towards either pole, that distance decreases until the lines meet at the poles. Understanding this concept is crucial for accurate surveying and mapping, as it influences calculations related to distance and angle measurement on the Earth’s surface.

The other options do not correctly describe this geographic feature or the behavior of meridians.