Lava domes are real fun.

In the case of Montserrat the dome collapsed producing a pyro flow 6 months after the eruption producing the dome ended. In that case it was because the dome got rained on producing steam inflation of fractures.

The paper did not report the weather @ Sinabung at the time of the dome collapse but there is a fair chunk of monsoon hitting S. China right about now so it is probably a mite wet in the vicinity of Sinabung closer to the monsoonal root.

Incidentally, on the subject of Monsoon, the Asia Pacific hot pool is very well developed right now so it is raining a lot in China and is a subdued & pulsating monsoon in India. The Chinese have no cause to complain about it as they have wanted to acquire a fair quantity of India for several decades. It seems only fair that they should have the monsoon as a taster.

Have a nice day: Ag