Today we're going to tell the story of a quiet revolution in the 1960s that shifted our entire understanding of how the Earth works. We currently believe that the Earth's broken outer shell rises from the mantle and folds back in - kind of like a dance of creative destruction and reconstruction - giving us our continents and oceans, mountains and valleys, volcanoes, and earthquakes. And it would take a group of scientists all over the world to get us this grand unifying theory of plate tectonics. SOURCES Petersen, et al 2011. Fundamentals of Physical Geography. Cengage Christopherson, R.W. 2010. Elemental Geosystems. Prentice Hall. 6th edition Strahler, A. 2011. Introducing Physical Geography. Wiley and Sons. 5th Edition http://metrocosm.com/earth-19000bc-3000ad.html https://dinosaurpictures.org/ancient-earth#750 https://earthsky.org/space/earth-as-seen-from-space-500-million-years-ago https://oceanexplorer.noaa.gov/explorations/lewis_clark01/background/seafloormapping/seafloormapping.html https://www.nationalgeographic.org/encyclopedia/ring-fire/ ttps://www.ck12.org/earth-science/Ocean-Ocean-Convergent-Plate-Boundaries/lesson/Ocean-Ocean-Convergent-Plate-Boundaries-HS-ES/ https://www.reference.com/science/oceanic-oceanic-collision-8f54388c339a8525 http://www.geosci.usyd.edu.au/users/prey/ACSGT/EReports/eR.2003/GroupD/Report1/web%20pages/assignment_1.html Watch our videos and review your learning with the Crash Course App! Download here for Apple Devices: https://apple.co/3d4eyZo Download here for Android Devices: https://bit.ly/2SrDulJ Crash Course is on Patreon! You can support us directly by signing up at http://www.patreon.com/crashcourse Thanks to the following patrons for their generous monthly contributions that help keep Crash Course free for everyone forever: Michael M. Varughese, Ben Follows, Kyle & Katherine Callahan, Laurel A Stevens, Chris Routh, Evan Lawrence Henderson, Vincent, Emilee Murphy, Michael Wang, Jordan willis, Krystle Young, Michael Dowling, Alexis B, Rene Duedam, Burt Humburg, Aziz, Nick, DAVID MORTON HUDSON, Perry Joyce, Scott Harrison, Mark & Susan Billian, Junrong Eric Zhu, Alan Bridgeman, Rachel Creager, Jennifer Smith, Matt Curls, Tim Kwist, Jonathan Zbikowski, Jennifer Killen, Sarah & Nathan Catchings, Brandon Westmoreland, team dorsey, Trevin Beattie, Divonne Holmes à Court, Eric Koslow, Indika Siriwardena, Khaled El Shalakany, Jason Rostoker, Shawn Arnold, Siobhán, Ken Penttinen, Nathan Taylor, William McGraw, Andrei Krishkevich, ThatAmericanClare, Rizwan Kassim, Sam Ferguson, Alex Hackman, Eric Prestemon, Jirat, Katie Dean, TheDaemonCatJr, Wai Jack Sin, Ian Dundore, Matthew, Jason A Saslow, Justin, Jessica Wode, Mark, Caleb Weeks __ Want to find Crash Course elsewhere on the internet? Facebook - http://www.facebook.com/YouTubeCrashCourse Twitter - http://www.twitter.com/TheCrashCourse Tumblr - http://thecrashcourse.tumblr.com/ Support Crash Course on Patreon: http://patreon.com/crashcourse CC Kids: null #CrashCourse #Geography #Tectonics