What is the most powerful natural catastrophic event on record?
hard to impossible to tell. In recorded history it was for sure one of those massive volcanic eruptions from Krakatoa, Yellowstone or Tambora. But in earth's history there were some impacts from meteorites or commets that must have been a lot more powerfull in terms of released energy than any volcanic erruption. My guess is the Vredefort crater in South Africa (largest verified impact crater on Earth with a diameter of 300 km) or the Chicxulub crater in Mexico that is said to have triggered the mass extinction of the dinosaurs.