Thread: (DEM) Digital Elevation Model

It's not "just" data. It's what kind* of data. DEM size depends on not only on coverage but also changes** in elevation. Furthermore, there are different level of accuracy. "Basemap" is lowest*** level (try highest zooming and compare) If you parsed the DEM file, you'll understand.

* "kind" includes NASA (raw data) and CGIAR (fixed data). So it's possible to see newer/better DEM to be smaller in CGIAR than NASA.
** data is height field, so mountainous places take more data to encode than flat places.
*** actually, some .fbl (map file) have the lowest/basic DEM data in them. Which only used at lowest zooming (planet view)