Sinkholes form through both natural and human-made processes. Most of us think about erosion on the surface of the earth, but erosion can occur in the subsurface as well. In fact, scientist and engineers have a very creative name for just such a process: internal erosion. If just the right factors come together in the subsurface, some very interesting things can occur, including sinkholes. Watch this video and the entire Practical Engineering catalog ad-free on Nebula: https://go.nebula.tv/practical-engineering -Patreon: http://patreon.com/PracticalEngineering -Website: http://practical.engineering/ Memories by SNDR & Joey Shigrov is licensed under a Creative Commons Attribution License Source: https://www.youtube.com/watch?v=S1Q2PpM5To8 Tonic and Energy by Elexive is licensed under a Creative Commons Attribution License Source: https://www.youtube.com/watch?v=U6fBPdu8w9U This video is sponsored by Blue Apron.