It is the base longitude line on a map

Because a topograpic map is a map that shows surface features, or topography of an area.

The 5th zombie map after Ascension for Black Ops is going to be held in a luner base (Ascension is a rocket facility, not a luner base.) And will have a new character in it named Yuri.

True

Go to custom games, find what base map the map was forged onto, find the map (it is organized alphabetically) and select it. If you select the map and it tries to load another re-download it, this worked for me.