GMTED2010 data set

[rese_support]

I have a question about an imported Global Elevation DEM, what is its vertical reference system? 

The provided data set of GMTED2010 is best described here:

https://pubs.usgs.gov/of/2011/1073/pdf/of2011-1073.pdf

There, it says:

"Most vertical heights in GMTED2010 are referenced to the Earth Gravitational Model 1996 (EGM 96) geoid (NGA, 2010)"

National Geospatial-Intelligence Agency (NGA), 2010. http://earth-info.nga.mil/GandG/wgs84/gravitymod/ (last refer- enced Jan. 11, 2011).