This learning activity uses data acquired by the TOPEX/Poseidon altimeter, a joint project of NASA and the French Space Agency, to investigate the relationship between the topography of a sea-floor feature and the topography of the overlying sea surface.

For over 20 years, satellite instruments have measured the sea surface height of our ever-changing oceans.  This video of images shows the complicated patterns of rising and falling ocean levels across the globe from 1993 to 2015.

In this activity, students use satellite images from the NASA Landsat team to quantify changes in glacier cover over time from 1986 to 2018.