Posted by Mark on Sunday, 14. February 1999 at 21:12 Bali Time:
In Reply to: Smoking in Bali posted by John Paul on Sunday, 14. February 1999 at 05:07 Bali Time:
Can't tell you about present activity but...
As far as I'm aware, Mt Batur is not a good candidate for pyroclastic flows because it's present vent is within a huge crater. Pyro flows are normally caused when the upper cone of a volcano collapses in on itself and creates a VERY hot ash cloud which rolls down the mountain. The cone has already obviously collapsed a long while ago at Batur. I would imagine the greatest immediate danger would be if you were in its crater from toxic gases and, of course, falling rocks / magna from any explosion.
Mt Agung would be a more likely candidate for a cone collapse.
Volcanoes generally give pronounced warning signs of a forthcoming erruption, such as tremors and lots of smoke. So, if there are these signs, stay well away. Pyroclastic flows normally travel down the mountainside along the natural river valleys. Therefore, keep well away from them. As these dust clouds have temperatures exceeding 400 degrees Celcius, you would suffer a painful death if you got caught by one (just ask the former residents of Pompey).
At 400 degrees, you would need to be within a sound structure away from glass (it shatter). You can not outrun a flow as it can travel much faster than even a car (don't sit in one). If you can submerge yourself in deep enough water for a minute or so, you may stand a chance. It's warm enough on Bali already!