About this 3D model

Inspired by a picture on the [USGS website](http://ga.water.usgs.gov/edu/gallery/global-water-volume.html) Each blue sphere is to scale assuming the Earth is a sphere with a radius of 40 cm (15.74 inches). The largest one is all of the water on Earth. The mid-sized sphere is all fresh liquid water and the smallest is lake and river water only. The white base is a slice of a 40 cm sphere (size of the Earth) More information [here](http://andrewstaroscik.com/views/2013/07/scale-model-of-the-water-on-earth)