6. these lines run between the geographic north and south pole

These lines are called lines of longitudes.

Explanation:

There is a difference between longitudes and lines of longitudes.

Longitude: It is the angular distance from one point location to another point location on the globe.This angular distance is measured with the help of lines of longitudes. Lines of longitudes: These are imaginary lines that run around the Earth vertically (up and down) and meet at the North and South Poles. These lines are also termed as meridians. The Prime Meridian is located at 0° and the lines of longitude run east and west of Prime Meridian. There are 360 longitudes in total (180 east and 180 west of Prime Meridian). Further, all longitudes are also great circles.  

Learn more:

The importance of latitude and longitude  Latitude and longitude of clifden ireland  

 Keywords: longitude, lines of longitude, Prime Meridian, North Pole, South Pole

Geologists use  seismic waves to  locate an earthquake's epicenter.. 

Answer collision and mountain formation;