Most of us measure the extent of natural disasters by calculating the death and destruction they wreak.
Thousands die, thousands of buildings collapse.
These days it's not just earthquakes that are assigned numbers to make them more comprehensible. Hurricanes, tornadoes, solar flares, asteroid impacts and other cataclysmic events are also rated on scientifically devised scales that enable us not only to condense a massive amount of information into a few numerals, but sometimes warn us about trouble that's on the way. Visit the Discovery Store for gifts and products that help you explore your world. In the Company of Whales . A video that reveals whale encounters never before captured on film.