RABAUL New Britain Island, Papua New Guinea 4.271°S, 152.203°E; summit elev. 688 m; All times are local (= UTC + 10 hours) Reports from 2001: | August-September | October | Reports from 2002: | February | October | November | December | Reports from 2003: | January | February | March | June | July | August | September | Reports from 2004: | March | Reports from 2005: | January | Rabaul Eruption History Information from the USGS Global Volcanism Program -------------------------------------------------------------------------------- 29 August- 4 September 2001 On 28 August very mild ash eruptions began. The eruptions followed an increase in the number and magnitude of low-frequency volcanic earthquakes a few days earlier. Eruptions continued until at least 31 August. Source: Rabaul Volcano Observatory via the Darwin VAAC -------------------------------------------------------------------------------- 26 September- 2 October 2001 During 10-30 September summit activity at Tavurvur, a stratovolcano of the Rabaul Caldera, was very low. During the report period very small-to-moderate amounts of steam were emitted from the active vent and low-frequency volcanic earthquakes decreased. After the 11th seismic activity was relatively low, except for a slight increase on the 16th. Very slow deflation began on 20 September. Source: Rabaul Volcanological Observatory -------------------------------------------------------------------------------- 10-16 October 2001 During 8-14 October summit activity at Tavurvur, a stratovolcano of the Rabaul Caldera, remained low and was dominated by weak-to-moderate emissions of white vapor. Low-frequency volcanic earthquakes continued to occur, but their number and size were relatively low. No significant ground deformation was detected. Source: Rabaul Volcanological Observatory -------------------------------------------------------------------------------- 20-26 February 2002 During 11-24 February volcanic and seismic activity were low at Rabaul's post-caldera cone, Tavurvur. Only white vapor was released from Tavurvur; emissions were blown to the SE and E resulting in vegetation being killed in the town of South Daughter (~2 km to the E). The Rabaul Volcanological Observatory stated that this suggests volcanic gases such as SO2 were being emitted. Source: Rabaul Volcanological Observatory -------------------------------------------------------------------------------- 16-22 October 2002 According to the Darwin VAAC, a large explosion occurred at Rabaul caldera on 20 October at 1347. They did not specify whether the eruption occurred from Tavurvur or Vulcan volcano. The eruption produced a thick, dark, ash plume that rose to ~3 km before dispersing to the N and NW. No ash was visible on satellite imagery due to meteorological clouds in the vicinity. The VAAC reported that similar explosions were expected to continue for the next couple of days. On the 23rd ash was visible at a height of ~3.6 km a.s.l. Source: Darwin VAAC -------------------------------------------------------------------------------- 23-29 October 2002 An eruption on 20 October from Tavurvur volcano took place at Rabaul caldera. The head of RVO stated that rocks were thrown 700 m from the summit and no lava was erupted. Ash from the eruption caused Tokua airport flights to be suspended on 22 October. It reopened on the 27th, with two flights permitted during the day. Reopening the airport was possible because ash from the eruption shifted away from it. Several small explosions occurred after the 20 October eruption and sent ash clouds to 4 km a.s.l. On the 28th RVO stated that a major increase in volcanic activity seemed unlikely. Sources: Darwin VAAC , Rueters, Pacific Island Report -------------------------------------------------------------------------------- 30 October-5 November 2002 Based on information from the Rabaul Volcano Observatory, the Darwin VAAC reported that low-level activity continued from Tavurvur volcano at Rabaul caldera through 4 November. Ash emissions occurred at long, irregular intervals and remained below ~3 km a.s.l. Source: Darwin VAAC -------------------------------------------------------------------------------- 20-26 November 2002 Very heavy ash emission was observed at Rabaul caldera's Tavurvur cone on 24 November. A low-level plume was produced and no ash was visible on satellite imagery. RVO advised on 25 November that ash emissions were continuing from Rabaul, but at a reduced rate in comparison to previous weeks. Observations revealed that the ash content in the emissions was generally decreasing, and erupted ash clouds remained below ~1.5 km a.s.l. Source: Darwin VAAC -------------------------------------------------------------------------------- 27 November-3 December 2002 The eruption at Rabaul caldera's Tavurvur cone continued through 3 December. The intensity of ash emission changed on 30 November from very slow to slightly forceful, and the interval between eruptions increased. Occasional moderate eruptions produced ash clouds that reached heights of 1-1.5 km above the crater. Two moderate explosions on the night of the 30th emitted visible incandescent lava fragments that showered the volcano's N and NE slopes and ash plumes that rose several hundred meters above the crater. On the evening of 3 December ash plumes were blown N and NW, causing fine ashfall in parts of Rabaul Town. During the report period, seismicity was at low-to-moderate levels. GPS measurements of ground deformation showed no significant changes, but electronic tiltmeters showed minor inflation. RVO stated that the current eruption at Tavurvur is expected to continue, but an increase in eruptive activity is unlikely. Source: Darwin VAAC -------------------------------------------------------------------------------- 4-10 December 2002 Through 11 December the eruption of Rabaul volcano's Tavurvur cone was characterized by slow, convoluted ash plumes that rose several hundred meters above the summit. There was a small amount of ash in the plumes, and minor ashfall affected areas close to the cone. Seismicity was low to moderate, and there was a ~2.5-minute-long period of harmonic tremor the morning of the 11th that was accompanied by a pulsating noise that emanated from the volcano. No ground deformation was recorded. Source: Rabaul Volcanological Observatory via Darwin VAAC -------------------------------------------------------------------------------- 11-17 December 2002 During 12-16 December, the eruption of Rabaul volcano's Tavurvur cone was characterized by slow, convoluted ash plumes that rose several hundred meters above the summit. Moderate amounts of ashfall affected areas close to the cone. Seismicity was low to moderate and no significant ground deformation was recorded. Although the NE vent was still dominant, some plumes also rose from the W side of the N crater. Source: Rabaul Volcanological Observatory via Darwin VAAC -------------------------------------------------------------------------------- 18-23 December 2002 During 17-20 December, the eruption of Rabaul volcano's Tavurvur cone was characterized by slow, convoluted ash plumes that rose several hundred to more than a thousand meters above the summit. Seismicity was low to moderate and no significant ground deformation was recorded. Source: Rabaul Volcanological Observatory via Darwin VAAC -------------------------------------------------------------------------------- 31 December 2002- 7 January 2003 Activity at Rabaul caldera's Tavurvur cone continued through 2 January, with eruptions occurring from three vents at different times. The eruptions were characterized by slow convoluted ash plumes rising several to thousands of meters above the summit. Seismicity was at low-to-moderate levels. No significant short-term deformation was recorded, following a very slow inflationary trend during the previous month. Source: Rabaul Volcanological Observatory via Darwin VAAC -------------------------------------------------------------------------------- 15-21 January 2003 Eruptions of Rabaul caldera's Tavurvur cone continued during 17-19 January, with activity from three different vents. Discrete convoluted ash plumes rose several hundred to a thousand meters above the volcano's summit. Plumes drifted N and NW, depositing small amounts of ash in Rabaul Town, and the villages of Malaguna, Matupit, Nonga, Tavai, Korere, and Rabura. During the report period, seismicity was at low levels. No significant short-term deformation was recorded, following a very slow inflationary trend during the previous 2 months. Source: Rabaul Volcanological Observatory via Darwin VAAC -------------------------------------------------------------------------------- 29 January- 4 February 2003 Eruptions of Rabaul caldera's Tavurvur cone continued during 27 January to 2 February, with steam-and-ash emissions occurring at irregular intervals and rising about a few hundred meters above the summit. Ash plumes were blown to the SE and seismicity fluctuated at low levels. Ground-deformation measurements showed a slight inflationary trend over the last couple of days in the report period. Source: Rabaul Volcanological Observatory via Darwin VAAC -------------------------------------------------------------------------------- 5-11 March 2003 The eruption at Rabaul caldera's Tavurvur cone continued during 26 February to 2 March. Activity was characterized by discrete, slow, convoluted ash plumes occurring at long, irregular intervals and rising slowly to several hundred to a thousand meters above the summit. Activity during the report period was slightly lower than activity during 17-26 February, with intervals between ash emissions becoming much longer. Ash emissions were blown to the E and SE. Seismicity remained at low levels and there were no significant changes in deformation. According to the Darwin VAAC, ash was not visible on satellite imagery. Sources: Rabaul Volcanological Observatory via Darwin VAAC, Darwin VAAC -------------------------------------------------------------------------------- 19-25 March 2003 Activity at Rabaul caldera's Tavurvur cone during 13-19 March was low in comparison with previous months. The eruption continued to be characterized by discrete, convoluted ash plumes occurring at long irregular intervals and rising slowly to several hundred meters above the summit. Ash emissions mainly drifted E and SE. Some light ashfall occurred in the town of Rabaul on 16 March. During the report period, seismicity was at low levels and deformation measurements fluctuated. Source: Rabaul Volcanological Observatory via Darwin VAAC -------------------------------------------------------------------------------- 18-24 June 2003 On 21 June a low-level plume from Rabaul was visible on satellite imagery extending ~11 km NW of the summit. Source: Darwin VAAC -------------------------------------------------------------------------------- 25 June-1 July 2003 There was a noticeable decline in ash eruptions from Rabaul caldera's Tavurvur cone on 22 June through at least 30 June. Around the 19th, ash plumes drifted NW, depositing ash in Rabaul Town and nearby villages. On 19 and 21 June ash emissions occurred within several minutes of each other, but on the 22nd the interval became much longer with no ash emissions occuring for as long as an hour. Ash-laden plumes rose between several hundred and ~1,500 m above the summit. Seismicity decreased on the 22nd, with the occurance of fewer low-frequency earthquakes that are associated with eruptive activity. No significant changes in deformation were recorded. Source: Rabaul Volcano Observatory -------------------------------------------------------------------------------- 13-19 August 2003 On 10 August at least three small low-intensity ash emissions were observed at Rabaul caldera's Tavurvur cone. On 13 August emissions produced ash clouds to a maximum height of ~1 km above the volcano. In August seismicity was at low levels and there were minimal ground movements. The volcano's edifice was inflated, and earthquakes occurred in the NE area of the volcano. Source: Rabaul Volcano Observatory -------------------------------------------------------------------------------- 27 August- 2 September 2003 On 10 August eruptions began again at Rabaul caldera's Tavurvur cone after 2 days of very little activity. Eruptions mainly consisted of slowly emitted convoluted ash plumes at irregular intervals. On 25 August discrete explosions began to occur. Most of the ash from the eruptions was blown NW, resulting in ashfall in towns downwind, including in Rabaul and the Nonga area. During 1 July to 28 August, seismicity was at low levels and the amount of deformation was insignificant. Source: Rabaul Volcano Observatory -------------------------------------------------------------------------------- 17-23 March 2004 Eruptive activity, which began at Rabaul caldera's Tavurvur cone in October 2002, ceased on 17 February. During 1-17 February, emissions of "light-to-pale ash clouds" were accompanied by occasional moderate explosions that produced thick ash plumes. The ash plumes rose 1-2 km above the summit and drifted E and NE, resulting in ashfall in Duke of York, Rabaul Town, and other villages. During 18-29 February there were only weak gas emissions. Ground-deformation measurements showed a deflationary trend during the last half of February. Source: Rabaul Volcano Observatory -------------------------------------------------------------------------------- 19-25 January 2005 Based on information from RVO, the Darwin VAAC reported that ash emissions commenced at Rabaul on 25 January. Ash rose to ~500 m above the summit and drifted E. Source: Darwin Volcanic Ash Advisory Center