Watching a programme on tv the other night, it was about Tectonics and Volcanoes. All really good info, except where it came to descibing the power of such cataclysmic events. For instance, the 2004 earthquake in Indonesia, which generated the Tsunami, that was the equivalent of a 5 gigaton nuke, now this is where the weights and measures comes into it, they then pointed out this was the same as 5000 Nagasaki bombs. Another, was the dust cloud created by an eruption, covered an area of 50,000 square miles, or the equivalent of Spain. a 30metre high Tsunami, eqivalent to a 9 storey building. I've heard other as well, like the Olympic size swimming pools, and 15 New York yelow cabs laid end to end. Any other mind boggling measures out there? why do they do it? Does it make it any easier to comprehend?