Geoscience:Volcano Hunter
More than 50 volcanoes erupt somewhere on earth every year. That's nearly once per week on average. More than half a billion people live on their slopes or near them. The Four Horsemen of the volcanic apocalypse are hot ash， rock fragments， lava and gas. The flow down a volcano’s mountainside can reach 200 or more kilometers per hour. When it does， a group of scientists using the most modern technology will be the first to sound the alarm.
- Added：2006
- Country：America
- Duration：60
- Time of update：2011/8/17 11:59:04