Activity of the Volcano
The latest eruptive phase of Bromo started in December 2015. The eruptive activity was in the beginning dominated by the ejection of ash and lapili. In late January and February the activity increased and larger explosions were seem, sometimes accompanied by the ejection of lava-bombs/blocks, loud eruption/rumbling sounds and shock-waves. In this period there were also days when strong crater-glow was seen above the crater at night.
The eruptive activity had a short period of rest between the end of February until the end of March. During this period the activity was dominated by degassing but no ash-venting/eruptions.
The Indonesian Volcanology Survey (PVMBG) noted a increase in seismic activity in the first week of April, that was followed by new eruptive activity. Ash-venting and crater-glow was observed. The ash-output was lower than February/March levels. Eruption/rumbling sounds was also present, but lower than January/February levels.
During the second week of April, the activity decreased again and only weak to moderate degassing plumes was observed during until first week of May.
The last week of May the activity increased again, and resumed eruptive activity similar to the activity observed in April.
During June and July the intermittent activity continued, days with only a degassing plume present and periods of low to medium strong ash-venting activity. In the second week of July, ash-fall caused the airport of Malang to close for a few days.
Note: The eruptive phase is still ongoing.
On the 23th July a medium strong degassing plume was present, however decreased in significance in the evening. The degassing was accompanied by a medium strong rumbling sound that was present throughout the day. Weak crater glow was visible on photos during a few times during the evening. On the 24th activity decreased, and only a weak plume was seen emitted from the crater, but there was also periods of complete calm. A similar state was observed on the 25th, until I departed the area at midday.
No ash eruptions was seen during this visit.