I have seen instances of water walls being experimented with to project a barrier in demolition cases that adequately stopped flying debris. With more money and a lot of effort, would this be a feasible way of damping down volcanic ash? As we've seen in the EU, this little problem with a volcano in Iceland has been spewing ash out that is getting into the airspace and is shifting around in the wind interfering with airtravel. Now, going back to cars/coaches/trains isn't so hard, and in a world of broadband internet people can conference over the web fairly easily. But, what if it goes on and on? http://news.bbc.co.uk/1/hi/uk/8685193.stm "Aviation expert David Learmount warns the ash could cause disruption for 20 years" I don't actually know right now whether ash is projected up into airspace at force and then swirled round, or if it has properties that allow it to gradually rise. I suppose I should go a googling. So, if it is going to continue on and on, then maybe an idea like this has merit. Obviously the engineering considerations are massive and the cost will be hefty, but it seems quite a similar problem really. How to stop objects hurled from an 'exlosive object' from traveling any further. A volcano is quite large, but I wonder if with a frame built round the volcano and water piped up and shot over it, whether it could be an effective barrier that will free the airspace? EDIT: interestingly, a friend says the lava would solidify, 'corking' the volcano and causing it to erupt somewhere else nearby?