"Unlocking" the full map?

I have a simple question, though I don't know if it's easy to understand what I'm trying to ask,

I've been playing MHGU but each time I do a quest and go to for example the Jurassic Frontier, the map is shown partially, like I can't see it fully due to fog. And I don't mean that I'm zoomed into the area.

So I'm assuming I need to "map" the map before I can see it completely? But how do I do that? Do I need a specific item?

To put it simple, when I go to the Jurassic Frontier, I don't see [this](http://i.imgur.com/5z6KskT.png) or [this](https://oyster.ignimgs.com/mediawiki/apis.ign.com/monster-hunter-generations/f/fc/JurassicFrontierAccounting1.png?width=1920). Instead I see only a small portion of the map, as if the rest is shrouded in fog.