I don't believe this is how pressure works. If you have a container full of pressurized gas and vent some of the gas out the gas in the container or the gas being released does not have its pressure increase. It can only decrease - unless the ambient pressure is higher than in the container which then would mean you couldn't vent what was in the container in the first place.
Well kind of the the it was explained on a volcano program on one of the science channels was that the gas is dissolved in the magma and remains under pressure, until the magma has an opening then the gas expands exponentially and explosively. I'm not sure a small opening would cause it to do that, but I still wouldn't want to be very close when the opening was made, and I'm also not sure a small opening would be able reduce the pressure enough to make a difference. So why try something with a very high risk and an unknown but most likely ineffective return?
I believe I understand what you were trying to say. I am being picky in youre explanation, however. What I am saying is that if the pressure of the magma increased through venting you would also have to be adding energy somewhere. What is happening in your senario is the potential energy of the magma (represented through it's high pressure) is being converted to kinetic energy (spewing out at high velocity) when the magma "container" is vented. The energy in the magma is just transferring from one form to another. I'm not debating the idea of venting this terrifying lava pit - just the explanation of your scenario. I found this wonderful site the other day and am glad to be here. :cheers:
