An ash cloud was generated at the Indonesian volcano Merapi this morning, rising to a height of 12,000 meters. The volcanic ash dispersed evenly around the volcano in light winds. Whether the ash cloud was generated by an explosive eruption, or the departure of a large pyroclastic flow, is not yet clear. I think the latter is likely, because the latest report from MAGMA/VSI states that Merapi generated 22 pyroclastic flows between 12:00 and 18:oo local time. It is also possible that this is volcanic ash that accumulated due to the numerous pyroclastic flows when there was no wind. Thus, the volcano entered a hot eruptive phase and things are getting dangerous at the volcano. Collapse events can generate pyroclastic flows that can affect localities beyond the current exclusion zone.