Prediction of Volcanic Eruptions - What Can Be Done?

Only one quarter of the eruptions since 19 50 were even monitored by something like a sismograph. 25 % of them, the other ones, they erupted and we had no really hard data on on what was happening. Only a third of that data was actually entered into the global data base for volcanic unrest. We don't even know where all these potentially active volcanoes are. This would obviously rigt this is what provides better, advanced warning of eruptions.