Based on satellite imagery and information from CVGHM, the Darwin VAAC reported diffuse ash plumes from Semeru at an altitude of 4.6 (15,000 ft) a.s.l. during 3-5 May. The plumes drifted SW.

Based on a news report, eruption plumes from Semeru drifted E on 10 and 11 February. Ashfall was reported from areas including the town of Lumajang, about 35 km E.

Based on a pilot report, the Darwin VAAC reported an ash plume riging to 7.6 km (25,000 ft) on 22 November, drifting to the S. Various other reports and news sources indicate that the crater's typical strombolian is relatively powerful these days and that blocks and bombs are frequently ejected outside the crater.

Based on a pilot report, the Darwin VAAC reported that on 18 October, an eruption plume from Semeru reached 4.6 km (15,000 ft) a.s.l.

Semeru volcano appears to be in a relatively active phase. based on satellite radar data, plumes from its ash eruptions have reached nearly 11 km a.s.l. during the past week.

Strombolian activity at Semeru was observed to be weak during the past days when our group observed and climbed the volcano. Ash emissions are taking place at irregular intervals of 5-20 minutes and rarely exceed 300-500 m in height. During the night, only little incandescent bombs and blocks are visible. 

Eruption plumes from Semeru were visible on satellite imagery on 2 August. They reached a maximum altitude of 5.2 km (17,000 ft) a.s.l.

According to the Darwin VAAC, on 24-25 and 31 July small plumes from Semeru were visible on satellite imagery and reached unknown altitudes.

Based on a pilot report, the Darwin VAAC reported that an ash plume from Semeru reached 5.5 km (18,000 ft) a.s.l. on 25 June.

According to the Darwin VAAC, satellite imagery showed small ash plumes from Semeru on 6 and 12 June and minor ash-and-steam plumes on 11 and 13 June, all at unknown altitudes.

According to the Darwin VAAC, a pilot reported multiple minor eruptions from Semeru on 4 June. Small ash plumes were detected on satellite imagery on 5-6 June.

An ash plume from Semeru at a height of 6.1 km (20,000 ft) a.s.l. was observed on satellite imagery.

Geologic Summary
Semeru is the highest volcano on Java and one of its most active. The symmetrical stratovolcano rises abruptly to 3,676 m above coastal plains to the S and lies at the southern end of a volcanic massif extending N to the Tengger caldera. Semeru has been in almost continuous eruption since 1967. Frequent small-to-moderate Vulcanian eruptions have accompanied intermittent lava dome extrusion, and periodic pyroclastic flows and lahars have damaged villages below the volcano. A major secondary lahar on 14 May 1981 caused more than 250 deaths and damaged 16 villages.

Semeru is in a state of high activity as observed by the VolcanoDiscovery team during the past days. Strong strombolian activity is taking place at frequent intervals of 5-10 minutes, producing billowing ash clouds of 1-2 km height and showering much of the summit cone with fresh gray ash.