The release in 1965 of Paramount's science fiction classic, Crack in the World, challenged scientists and engineers to think about the possibility that a giant dike could fracture Earth's brittle crust and encircle the planet. The movie also offered a solution to the hydrocarbon energy crisis and global warming decades before anyone thought these were serious problems.

In this seminar I will replay key cuts from this sci-fi movie thriller and show how geology, volcanology, elasticity theory and fracture mechanics help one to separate fact from fantasy. I will use data reviewed in Townsend et al., 2017, Tectonophysics to argue for a third school of thought regarding mechanical models for dikes. Also, I will use model results published in Pollard & Townsend, 2018, JSG to highlight the role of gravity and a stratified crustal density to stabilize giant dikes, even if the fracture toughness of rock is zero. Finally, I will explore interesting instabilities for fluid-filled fractures predicted by the model results.