SEMERU Java, Indonesia 8.11°S, 112.92°E; summit elev. 3,676 m; All times are local (= UTC + 7 hours) Reports from 2000: | December | Reports from 2001: | March | April | May | July | September-October | Reports from 2002: | March | April | June-July | August | September | December | Reports from 2003: | January | February | March | April | May | June | July | August | September | October | November | December | Reports from 2004: | April | May | June | July | August | Reports from 2005: | May | Reports from 2006: | March | April | "Reports provided courtesy of the Smithsonian's Global Volcanism Program and the US Geological Survey's Volcano Hazards Program." 6-12 December 2000 On 11 December an air report to the Darwin VAAC stated that volcanic ash was observed near Semeru at an altitude of ~7.6 km a.s.l. The Darwin VAAC stated that the activity may have been associated with Semeru, which frequently erupts ash to ~4.5 km. Due to cloudy conditions, any low-level volcanic activity that was occurring at that time was not visible in satellite imagery. Source: Darwin VAAC 13-19 December 2000 The VSI reported that during 5-11 December fume from Jonggring Seloko crater located in the S sector of Semeru's summit rose up to 600 m above the crater. The seismic record was dominated by explosion earthquakes and the record showed that two pyroclastic flows occurred. The volcano remained at Alert Level 2 (ranging from 1 to 4). Source: Volcanological Survey of Indonesia 28 February-6 March 2001 The VSI reported that a small steam plume rose ~100 m above Semeru's summit and that seismicity was dominated by 702 explosion earthquakes. In addition to the explosion earthquakes, three deep volcanic, 58 avalanche, and five tectonic earthquakes occurred. The volcano remained at Alert Level 2 (on a scale of 1 to 4). Source: Volcanological Survey of Indonesia 21-27 March 2001 The summit of the volcano was covered by clouds during 12-18 March, but the seismic record showed increasing activity. Explosion and avalanche earthquakes still dominated seismicity and increased over the past week. There were 349 explosion earthquakes, an increase over the 303 detected during 6-12 March. The count of explosion earthquakes decreased to 259 the week of 19-26 March. Semeru is at hazard level 2 (on a scale of 1-4). Source: Volcanological Survey of Indonesia 4-10 April 2001 During 27 March-1 April, VSI personnel observed several lava avalanches that traveled to Kembar River valley as far as 750 m S of the summit. No seismic data were available because the seismometers broke on 24 March 2001. They were repaired on 1 April. Semeru is at hazard level 2 (on a scale of 1-4). Source: Volcanological Survey of Indonesia 11-17 April 2001 There was a significant increase in the number of earthquakes detected at Semeru during 2-9 April following a decrease in volcanic activity during the previous several weeks. Seismographs recorded 28 deep volcanic earthquakes, 305 explosion events, 248 avalanche events, and 3 tectonic earthquakes. Cloudy conditions prohibited visual observations. Semeru remained at Alert Level 2 (on a scale of 1-4). Source: Volcanological Survey of Indonesia 18-24 April 2001 VSI reported that during 9-15 April activity at Semeru was higher than normal. Minor explosions that rose 300 m above the volcano were observed during clear weather. Seismographs recorded an increase in seismicity in comparison to the previous week, with 339 explosion events, 51 avalanche events, and three tectonic earthquakes. Semeru remained at Alert Level 2 (on a scale of 1-4). Source: Volcanological Survey of Indonesia 25 April- 1 May 2001 Volcanic activity increased at Semeru in comparison to the previous week, with an increase in explosion and deep volcanic earthquakes. Seismographs recorded 550 explosion events, 149 avalanche events, and ten tectonic earthquakes. Gas explosions rose up to 300 m above the volcano. Semeru remained at Alert Level 2 (on a scale of 1-4). Source: Volcanological Survey of Indonesia 2-8 May 2001 Volcanic activity increased at Semeru in comparison to the previous week. Seismographs recorded 759 explosion events (550 last week), 157 avalanche events, and four tectonic earthquakes. Semeru remained at Alert Level 2 (on a scale of 1-4). Source: Volcanological Survey of Indonesia 4-10 July 2001 Based on information from pilot reports and the Meteorological and Geophysical Agency of Indonesia, the Darwin VAAC reported that on 8 July at 1503 a SE-drifting ash plume rose to ~2.5 km above the volcano. Ground based reports prior to the eruption revealed that each day during 18-24 June Semeru emitted ash to ~0.6 km above the volcano. Source: Darwin VAAC 11-17 July 2001 Seismic data revealed that during 2-8 July the number of explosions and avalanche earthquakes at Semeru decreased in comparison to the previous week. The volcano was at Alert Level 2. Source: Volcanological Survey of Indonesia 18-24 July 2001 Seismic data revealed that during 9-15 July activity was higher than in the previous week. During this period 687 explosion events were recorded, as well as 57 avalanches, and 11 tectonic earthquakes. The volcano remained at Alert Level 2 (on a scale of 1-4). Source: Volcanological Survey of Indonesia 26 September- 2 October 2001 According to the Darwin VAAC, a pilot reported observing an ash plume rising 1-4 km above Semeru on 1 October at 1457. No ash was visible in satellite imagery, possibly due to low-level meteorological clouds obscuring the plume. Source: Darwin VAAC 3-9 October 2001 VSI reported that as of 5 October volcanic activity at Semeru was at normal levels, with a plume rising ~600 m above the volcano. Source: Volcanological Survey of Indonesia 6-12 March 2002 An increase in volcanic and seismic activity at Semeru during 3-10 March led VSI to raise the Alert Level from 1 to 2 (on a scale of 1-4). On 8 March observers saw an emission rise ~400 m above the volcano, and two pyroclastic flows travel S as far as 2.5 km down the Kembar River. During the report period there was an increase in tectonic and volcanic earthquakes in comparison to the previous week. Source: Volcanological Survey of Indonesia 20-26 March 2002 Volcanic and seismic activity remained high at Semeru during 11-17 March. Observations on 12, 14, and 17 March revealed that a gray plume rose 300-400 m above the summit. Seismicity was dominated by 444 explosion earthquakes, and there was a decrease in the number of tectonic and deep volcanic earthquakes in comparison to the previous week. The volcano remained at Alert Level 2 (on a scale of 1-4). Source: Volcanological Survey of Indonesia 24-30 April 2002 Volcanic activity remained higher than normal at Semeru during 15-21 April. A small plume rose ~400 m above the summit and a "red reflection" was occasionally visible 25 m above the crater rim. Lava avalanches traveled 750 m to the E down Besuk Kembar River. The volcano remained at Alert Level 2. Source: Volcanological Survey of Indonesia 26 June-2 July 2002 During 17-23 June, seismic and volcanic activity were higher than normal at Semeru. Lava avalanches were observed traveling 750 m E to the Besuk Kembar River. Seismicity included 670 explosion events. Semeru remained at Alert Level 2 (on a scale of 1-4). Source: Volcanological Survey of Indonesia 10-16 July 2002 When weather conditions were clear during 1-7 July, lava avalanches were sometimes observed traveling 750 m from Semeru's crater rim E toward Besuk Kembar River. Seismicity decreased in comparison to the previous week. Semeru remained at Alert Level 2 (on a scale of 1-4). Source: Volcanological Survey of Indonesia 17-23 July 2002 When weather conditions were clear during 8-14 July, lava avalanches were sometimes observed traveling 750 m from Semeru's crater rim E toward Besuk Kembar River. Low-level ash plumes rose above the crater. Seismicity was dominated by 898 explosion earthquakes, while the number of other types of earthquakes decreased. Semeru remained at Alert Level 2 (on a scale of 1-4). Source: Volcanological Survey of Indonesia 24-30 July 2002 When weather conditions were clear during 15-21 July, lava avalanches were observed traveling ~750 m from Semeru's crater rim E toward Besuk Kembar River. Explosions produced ash plumes reaching 300-500 m above the crater. Seismicity was dominated by 670 explosion earthquakes, while the number of other types of earthquakes decreased in comparison to the previous week. Semeru remained at Alert Level 2 (on a scale of 1-4). Source: Volcanological Survey of Indonesia 31 July-6 August 2002 Activity at Semeru remained at a higher level than normal, but thick fog obscured the view. Seismicity increased compared to the previous week and was dominated by 744 explosion earthquakes. Semeru remained at Alert Level 2 (on a scale of 1-4). Source: Volcanological Survey of Indonesia 21-27 August 2002 During 5-18 August, volcanic and seismic activity at Semeru remained at higher-than-normal levels. On 6 August a lava avalanche traveled ~750 m E toward Besuk Kembar River. Seismicity consisted of tectonic, explosion, and avalanche earthquakes. Semeru remained at Alert Level 2 (on a scale of 1-4). Source: Volcanological Survey of Indonesia 11-17 September 2002 On 8 September at 1947 an ash explosion at Semeru was accompanied by ejected incandescent material. The material traveled 150 m E to the upper portion of the Kembar River. During 2-8 September, seismicity was dominated by explosion earthquakes. Semeru remained at Alert Level 2 (on a scale of 1-4). Source: Volcanological Survey of Indonesia 18-24 September 2002 Ash clouds were observed at Semeru rising to ~7.6 a.s.l. on 22 September at 1453 and on 23 September at 1700. The September 23rd cloud drifted SW. Neither cloud was visible on satellite imagery due to meteorological clouds in the area. Source: Darwin VAAC 24-30 December 2002 During 9-22 December, volcanic and seismic activity remained above normal levels at Semeru. Ash columns rose 400-500 m above the volcano, and lava avalanches and pyroclastic flows were seismically recorded. The Alert Level was at 2 (on a scale of 1-4). According to news articles, the emission of lava and hot gas caused authorities to ban all recreational activity at Semeru beginning on 22 December. Sources: Volcanological Survey of Indonesia, News.com.au, Channelnewsasia.com 31 December 2002- 7 January 2003 Volcanic and seismic activity were relatively high at Semeru during 17-30 December. During the report period the most notable seismically recorded events were 1,085 explosions, 49 lava avalanches, 6 pyroclastic flows, and 3 floods/lahars. Explosions sent ash plumes to 400 m above Jonggring Seloko crater. On 25 December a pyroclastic flow traveled 2.5 km into the Besuk Kembar River. On 29 December during 1700-2015, a lahar traveled along the Besuk Kembar River relatively close to Supit village. Early that morning the residents of Supit were evacuated. On 30 December pyroclastic flows traveled 2 km toward the Besuk Kembar River at 0720, and at 1000 one traveled 4 km toward Supit village. The Alert Level at Semeru remained at 2 (on a scale of 1-4). Source: Volcanological Survey of Indonesia 8-14 January 2003 Relatively high volcanic and seismic activity continued at Semeru during 1-12 January. Several explosions sent ash columns to 700 m above the crater. Lava avalanches sent material up to 750 m from the crater rim and a pyroclastic flow traveled 1.5 km E to the Besuk Kembar River. Semeru remained at Alert Level 2 (on a scale of 1-4). Source: Volcanological Survey of Indonesia 22-28 January 2003 During 13-26 January volcanic activity remained at relatively high levels at Semeru, with ash plumes rising 400-600 m above the summit. On 19 and 23-24 January incandescent lava avalanches traveled ~500 m down Besuk Kembar River. Semeru was at Alert Level 2 (on a scale of 1-4). Source: Volcanological Survey of Indonesia 5-11 February 2003 During 3-9 February, volcanic activity remained at high levels at Semeru, with ash plumes rising 300-400 m above the summit. On 7 February a pyroclastic flow traveled 2-4 km into the Besuk Bang River. Seismicity during the report period was dominated by 777 explosion events and 14 pyroclastic flows were recorded. Semeru remained at Alert Level 2 (on a scale of 1-4). Source: Volcanological Survey of Indonesia 5-11 March 2003 During 24 February to 2 March, volcanism at Semeru remained at high levels. "White-gray ash plumes" were observed rising 300-400 m above the summit. Seismicity was dominated by 629 explosion earthquakes. Semeru remained at Alert Level 2 (on a scale of 1-4). Source: Volcanological Survey of Indonesia 12-18 March 2003 During 3-9 March, volcanism at Semeru remained at high levels. "White-gray ash plume[s]" rose to low levels above the summit and several "pyroclastic avalanches" traveled 200-2,000 m into Besuk Kembar River. Seismicity was dominated by 794 explosion earthquakes. The Alert Level at Semeru remained at 2 (on a scale of 1-4). Source: Volcanological Survey of Indonesia 19-25 March 2003 During 10-16 March at Semeru, "white-gray ash plumes" rose to low levels and several pyroclastic flows traveled 1.5-4 km down Bang River. Seismicity was dominated by 550 explosion earthquakes. Semeru remained at Alert Level 2 (on a scale of 1-4). Source: Volcanological Survey of Indonesia 26 March-1 April 2003 Seismic and volcanic activity continued at relatively high levels at Semeru during 17-23 March, with "gray ash plumes" rising 300-400 m above the summit, and several pyroclastic flows traveling toward Bang River to runout distances of around 500 m. Seismicity was dominated by 563 explosion events. Semeru remained at Alert Level 2 (on a scale of 1-4). Source: Volcanological Survey of Indonesia 2-8 April 2003 Seismic and volcanic activity continued at relatively high levels at Semeru during 24-30 March, with "gray ash plumes" rising to low levels, pyroclastic-flow activity, and several explosions. On 27 March a pyroclastic flow travelled around 3,750 m toward Bang River. During the week, seismicity was dominated by 794 explosion events. Semeru remained at Alert Level 2 (on a scale of 1-4). Source: Volcanological Survey of Indonesia 9-15 April 2003 Volcanic activity remained at relatively high levels at Semeru during 31 March to 6 April. "White-gray ash plumes" rose 400-600 m above the summit and seismicity was dominated by 738 explosion events. According to the Darwin VAAC, a pilot reported seeing ash ~2.5 km above Semeru on 15 April at 1038. No ash was visible on satellite imagery. The Alert Level at Semeru remained at 2 (on a scale of 1-4). Sources: Volcanological Survey of Indonesia, Darwin VAAC 16-22 April 2003 During the week of 16-22 April, Semeru was continually active. A white-gray ash plume rose 400-500 m over the summit. Seismic signals interpreted as pyroclastic flows were recorded multiple times during the week. One pyroclastic flow on 18 April traveled into several local drainages, reaching lengths of ~2.5 and ~3.5 km. Source: Volcanological Survey of Indonesia 21-27 May 2003 Volcanic and seismic activity at Semeru continued at relatively high levels during 12-18 May. Several small ash explosions rose to low levels above the summit. Seismicity was dominated by 730 explosion events. Semeru remained at Alert Level 2 (on a scale of 1-4). Source: Volcanological Survey of Indonesia 28 May-3 June 2003 Plumes emitted from Semeru were visible on satellite imagery at a height of ~6 km a.s.l. on 29 May at 0838 drifting NW, and on 2 June at 0625 drifting SSE. Source: Darwin VAAC 2-8 July 2003 During 2-29 June, activity continued at high levels at Semeru. Several explosions occurred during the report period, with the highest ash plumes rising to a height of ~600 m. Seismicity was dominated by hundreds of explosion events per week. Semeru remained at Alert Level 2 (on a scale of 1-4). Source: Volcanological Survey of Indonesia 16-22 July 2003 An ash cloud from Semeru was visible on satellite imagery on 21 July at 2316 extending ~75 km to the WSW. Source: Darwin VAAC 30 July- 5 August 2003 Based on information from an aircraft report, the Darwin VAAC reported that an ash plume emitted from Semeru rose to ~4.5 km a.s.l. on 31 July at 1120. No ash was visible on satellite imagery. Source: Darwin VAAC 6-12 August 2003 Thin ash plumes from Semeru were visible on satellite imagery on 8 and 9 August. On 9 August the plume extended ~40 km SW of the volcano. Source: Darwin VAAC 13-19 August 2003 A faint ash plume from Semeru was visible on satellite imagery on 13 August, extending ~75 km E of the summit. Source: Darwin VAAC 20-26 August 2003 During 11-17 August, volcanic activity at Semeru continued at relatively high levels. Explosions produced ash columns that rose to 400 m above the summit. Seismicity was dominated by 550 explosion earthquakes. Semeru remained at Alert Level 2 (on a scale of 1-4). Source: Volcanological Survey of Indonesia 3-9 September 2003 An ash plume emitted from Semeru on 9 September rose to ~7.3 km a.s.l. and drifted S. Ash was not visible on satellite imagery. Source: Darwin VAAC 8-14 October 2003 During 1-28 September, volcanic activity at Semeru continued at relatively high levels. Several ash explosions produced plumes to 400-500 m above the volcano. Seismicity was dominated by as many as 735 explosion earthquakes per week. Semeru remained at Alert Level 2 (on a scale of 1-4). Source: Directorate of Volcanology and Geological Hazard Mitigation 29 October- 4 November 2003 During October, ash explosions at Semeru continued to produce low-level plumes and seismicity was dominated by hundreds of explosion earthquakes. Semeru remained at Alert Level 2 (on a scale of 1-4). Source: Directorate of Volcanology and Geological Hazard Mitigation 3-9 December 2003 Satellite imagery on 2 December at 1728 showed an ash plume from Semeru at ~4 km a.s.l. that extended ~55 km WSW. Source: Darwin VAAC 14-20 April 2004 The Darwin VAAC reported that ash plumes from Semeru were visible in satellite imagery on 18 and 20 April. The plumes reached heights of ~4.5 km and extended ~90 km NW and ~75 km SSE, respectively. Source: Darwin VAAC 21-27 April 2004 The Darwin VAAC reported that an ash plume from Semeru was visible on satellite imagery on 21 April. The plume rose to ~4.6 km a.s.l. and drifted ESE. Source: Darwin VAAC 19-25 May 2004 The Darwin VAAC reported that a thin ash plume from Semeru was visible on satellite imagery on 23 May around 0625. The plume reached a height of ~4.3 km a.s.l. and extended ~110 km SSE. Source: Darwin VAAC 2-8 June 2004 An ash plume from Semeru was reported on 4 June at ~4.5 km a.s.l. Source: Darwin VAAC 16-22 June 2004 Based on information from a pilot's report, the Darwin VAAC reported that on 18 June an ash cloud from Semeru was visible at a height of ~6 km a.s.l., extending ~40 km E. Ash was not visible on satellite imagery. The Darwin VAAC reported that DVGHM listed the volcano at Alert Level 2 (on a scale of 1-4). Source: Darwin VAAC 14-20 July 2004 A pilot reported an ash plume from Semeru on 18 July at a height of ~3 km a.s.l. drifting NW. No ash was visible on satellite imagery. Source: Darwin VAAC 4-10 August 2004 During 5-10 August, pilots reported to the Darwin VAAC that several ash clouds were emitted from Semeru. The highest rising cloud reached ~7.6 km a.s.l. Ash was not visible on satellite imagery. The Alert Level at Semeru was at 2 (on a scale of 1-4). Source: Darwin VAAC 11-17 August 2004 A pilot reported to the Darwin VAAC that on 10 August ash from Semeru was at a height of ~6.1 km a.s.l. According to a news article, people were temporarily banned from climbing the volcano. Source: Darwin VAAC, Australian Broadcast Corporation 18-24 August 2004 On 24 August a thin plume emitted from Semeru was visible on satellite imagery extending to the WSW. Source: Darwin VAAC 25-31 August 2004 On 25 August, a thin plume emitted from Semeru was visible on satellite imagery extending WSW. No ash was visible on the satellite imagery. Source: Darwin VAAC 18-24 May 2005 Satellite imagery on 21 May showed a thin plume from Semeru at a height of ~4.6 km (~15,000 ft) a.s.l. extending to the S and later SSE. Source: Darwin VAAC 25-31 May 2005 The Darwin VAAC received a report that a small plume was visible above Semeru's summit on 25 May. Source: Darwin Volcanic Ash Advisory Center 8-14 March 2006 Based on information from the Center of Volcanology and Geological Hazard Mitigation (CVGHM formerly DVGHM), the Darwin VAAC reported that "ash rain" from Semeru was reported near the volcano. Ash was not visible on satellite imagery. Source: Darwin Volcanic Ash Advisory Center 19-25 April 2006 Based on information from a significant meteorological forecast (SIGMET), the Darwin VAAC reported that on 22 April an eruption at Semeru generated a plume that rose to ~4 km (13,000 ft) a.s.l. Ash was not visible on satellite imagery. Source: Darwin Volcanic Ash Advisory Center 10-16 May 2006 An ash plume from Semeru at a height of 6.1 km (20,000 ft) a.s.l. was observed on satellite imagery. Source: Darwin VAAC -