Question: if every volcano on earth erupted at the same time what would happen

Matthew Pankhurst answered on 15 Jun 2013:

Wow, what a sight that would be!
When a single volcano erupts, three things happen. The first is a shockwave from the explosion. The amount of energy released when a mountain splits apart is pretty big! Whole forests have been knocked flat in a single go. The second is that rocks are thrown out of the ground and into the atmosphere. These rocks can be tiny (so small you can’t see them) or huge (the size of houses and bigger!). Watch out! The magma (another word for lava when it’s underground) freezes and splinters like glass breaking. The third is that toxic gas is released into the atmosphere. This is deadly to just about anything in it’s path, and can even alter the atmosphere to make summer into winter. Depending on how big the volcano is, these three things can be extremely damaging or actually pretty tame. Each individual volcano is different, and each eruption is different, which is why it’s so fun and important to study them. So, if every volcano on earth (there are well over 1,000 active volcanoes on earth today) erupted at the same time life on earth would be changed forever. One volcano called Yellowstone could wipe out half of the USA in a single eruption, and there are huge volcanoes in south east Asia that would destroy a similar size area. So if you survived these massive explosions, food would probably run out because the volcanic dust and gas would block the sun out, and nothing would grow. I doubt the surviving humans could adapt to their new destroyed global environment fast enough to survive very long! However, it’d sure be an amazing sight to see (just not for very long….!)