Lake Mega Chad. Combined satellite data and elevation data from the Shuttle Radar Topography Mission (SRTM) showing the area once covered by Lake mega Chad. Lower-elevation areas are darker. Lake Mega Chad was present 7,000 years ago and at it's peak covered more than 400,000 square kilometres. The modern Lake Chad (black area at lower centre left) is just a fraction of Lake Mega Chad's size. Satellite data from the Operational Land Imager (OLI) on the Landsat 8 satellite.