Given that I am not a geo9ligist, or volcanologist, I have no expertise whatsoever on this subject, however,
I have noticed that long shots of this volcano - from over the 8km exclusion zone seem to show that all the ground in the area has that lush luxuriant green growth that you find around major volcano ash deposit zones. So to me it appears that what this volcano does when it really goes off is that is covers a much wider area than this exclusion zone, and that eruptions can be way larger than it seems the authorities have envisaged - if you eve want to know what a specific volcano does, I assume its a good idea to look at past history, and if that is lacking(especially going back a few thousand year) then it make sense to examine the previous fall out.
I bet that the local authorities exclusion zone is based on the 1962 eruption and I think that is somewhat unwise to make such an assumption.
This specific volcano seems to have relatively poorly documented history, but previous eruptions seem to have been around 30 or so years apart - and its been over 50 years since the last one, does this mean we could be in for a much larger event?
Also, worth considering, it has some relatively near neighbours - at least that’s how it appears on maps - these are pretty noteworthy, so I assume they are on the same tectonic edge line - these are Krakatoa, we all know what that one does when it goes off properly, then we have Mount Tambora - year without a summer anyone? and also we have Mt Rinjani which has fairly recently been accepted as the cause of the worldwide ‘little ice age’ around 1257. These are close enough to be within sight of each other.
We could have a very significant event on our hands, but I doubt that a wider evacuation would have much support simply because we have not seen it go off big time in our recorded history, only time will tell
My daughter and son-in-law were there last weekend, and left just before the airport closed. Did you know that the safety card for airplanes flying into Bali have a “what to do in case of volcano” section? (Put your head between your legs in crash position, basically.
There is a lot of ash, but I wouldn’t quite say it blew its top yet. Remember back when the volcano in island screwed up air travel for weeks? Not surprising the airport is closed.
Voyager, fortunately your family got off the island.
This is terrible for Bali and hopefully they can maximize the number of people out of harm’s way.
As for evac zones, it isn’t my profession but determining where the lines are drawn, I imagine, are based on statistical likelihoods of probable severities — e.g., 95% chance of likely death vs 95% chance of likely bodily harm; or 40% chance of likely death vs 40% chance of likely bodily harm. Then that, coupled with weighing the political and economic pressures, and someone is the ultimate arbiter of where those lines are drawn. And then it’s a matter of notifying people within those lines, and that’s an imperfect process.
Bali does have a regular (hourly, iirc) ferry running to Java, which also has a large international airport, in Jakarta, as well as smaller regional airports, so getting tourists off the island isn’t as bad an issue as it could be. There are delays reported all round the area due to planes being stranded at Bali, so it’s not quick or easy to get away, but tourists aren’t really stranded at the moment, just badly inconvenienced. Assuming ash and smoke don’t manage to blow in just the wrong way to cause airspace problems in Java as well.
It’s the locals that I’d worry about; there are some very poor people in the area who are really going to be unwilling to evacuate and leave crops and possessions. Until it’s too late, of course.
Even if they do evacuate everyone, but the area’s badly damaged by ash, that’s going to cause big problems locally.
As I post this, the view is dull (mostly just clouds) but last night it was fairly entertaining. Unfortunately the feed is in black and white, so there is no ominous red glare. But you could still see the light from the lava quite dramatically from time to time. And this morning, before the clouds obscured it all, it was smoking pretty ferociously.
Human nature will become a problem if they call for evacuations and there is no eruption. By the third evac to be on the safe side, people will start to decline evacuating. We see it in hurricane zones periodically until a fair number of people die in a big storm. After the deadly events people take the evacs much more seriously for a while but then 3-5 evacs without devastation and people start getting false confidence there is no need.
Not much the Government of Bali can do about this, they need to call for the evacuations and hope when and if the volcano actually blows people followed the evac orders.