US Topo GeoPDFs
June 9, 2013 | USGS on YouTube
This is a video tutorial that will demonstrate how to use USGS topographic maps in PDF format.
How Trees Defy Gravity
November 12, 2013 | Veritasium on YouTube
How can water be transported from the ground to the leaves at the top of a 100-meter-tall-tree?
November 5, 2013 | iConservePA
A quick video review of ground water in Pennsylvania.