for months or years. really. mixing technology improved in some respects and being able to measure science.how big is our ability to measure this? these volcanoes are very closely studied. look for things like the earthquake activity or some change in composition of the gases coming out. maybe just the forecast but is difficult to dictate exactly when and how eruption will be. they could go on for months or years, is that correct? yes judging from other eruptions in the past in hawaii this can go on for quite a long time. so what do folks do at this point? national park, people will not be able to go there because of this. i think where the lava is, that will continue and people still have houses there, they are in peril.