What would a magnitude 15 earthquake be like? Get a copy of What If? 2 and Randall’s other books at: https://xkcd.com/books
More serious answers to absurd questions at: https://what-if.xkcd.com/
Since we usually hear about earthquakes with ratings somewhere between 3 and 9, a lot of people probably think of 10 as the top of the scale and 0 aearthquake LINK