Activity for the week of 27 August-2 September 2003
The Weekly Volcanic Activity Report is a cooperative project between the Smithsonian's Global Volcanism Program and the US Geological Survey's Volcano Hazards Program. Updated by 2300 UTC every Wednesday, notices of volcanic activity posted on these pages are preliminary and subject to change as events are studied in more detail. This is not a comprehensive list of all of Earth's volcanoes erupting during the week, but rather a summary of activity at volcanoes that meet criteria discussed in detail in the "Criteria and Disclaimers" section. Carefully reviewed, detailed reports on various volcanoes are published monthly in the Bulletin of the Global Volcanism Network.
New Activity / Unrest
| Eastern Kamchatka (Russia)
| 54.049°N, 159.443°E
| Elevation 1513 m
Due to increased volcanic activity at Karymsky, KVERT raised the Concern Color Code to Orange from Yellow on 29 August. On 29 August at 1240 and 1612 explosions occurred that produced ash plumes to heights of 4-4.7 km a.s.l. The plumes drifted E. During 22-29 August, seismicity was above background levels, with about 180 shallow earthquakes per day. These earthquakes indicated possible ash-and-gas explosions to heights of 1-1.5 km above the volcano.
Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
| Flores Island (Indonesia)
| 8.542°S, 122.775°E
| Elevation 1703 m
The Darwin VAAC reported that an eruption at Lewotobi on 1 September produced an ash plume to a height of ~2.5 km above the summit that drifted W. Volcanic material caused fires in forests within a 1 km radius of the crater and damaged crops on the volcano's flanks. VSI raised the Alert Level to 4, the highest level. According to news articles, hundreds of people from at least six villages fled their homes for the village of Konga to the E. By 2 September the Alert Level had been reduced to 3.
Sources: Darwin Volcanic Ash Advisory Centre (VAAC), Agence France-Presse (AFP)
| Sulawesi (Indonesia)
| 1.112°N, 124.737°E
| Elevation 1785 m
On 2 September ash emissions from Soputan rose to ~2 km a.s.l. and drifted S and W. The Alert Level was raised from 2 to 3 (on a scale of 1-4).
Source: Darwin Volcanic Ash Advisory Centre (VAAC)
| 19.514°N, 103.62°W
| Elevation 3850 m
According to the Universidad de Colima, an explosion at Colima on 28 August at 2352 produced an ash plume that rose to a height of ~3 km above the volcano's crater. The explosion was accompanied by pyroclastic flows that traveled 2 km down the S flank and volcanic blocks. Residents of the city of Colima, ~32 km from the volcano, heard the explosion and ash fell in the town of Grullo, ~60 km NW of the volcano. Seismic data revealed that this explosion was similar in size to one on 2 August.
Sources: Centro Universitario de Estudios e Investigaciones de Vulcanologia - Universidad de Colima, Washington Volcanic Ash Advisory Center (VAAC), Associated Press
| Halmahera (Indonesia)
| 1.693°N, 127.894°E
| Elevation 1229 m
On 28 August an ash plume from Dukono was visible on satellite imagery at a height of ~4.3 km a.s.l. extending ~90 km N of the summit.
Source: Darwin Volcanic Ash Advisory Centre (VAAC)
| Grand Comore Island
| 11.75°S, 43.38°E
| Elevation 2361 m
Reports of a stream of lava flowing from Karthala towards towns on 30 August were false. Authorities stated that only fume was emitted from cracks on the volcano.
Source: Agence France-Presse (AFP)
| Hawaiian Islands (USA)
| 19.421°N, 155.287°W
| Elevation 1222 m
A M 5.0 earthquake occurred 10 km beneath Kilauea's central S flank on 26 August at 2024. It was the largest earthquake since 2 April 2000, an event that occurred in almost exactly the same spot. No significant damage was done, no cracks or rockfalls were seen, and there was no change in the eruption. During 27 August to 1 September, surface lava flows were sometimes visible on the coastal flat and upslope on Pulama pali. Generally, seismicity at Kilauea's summit continued at moderate levels, with 1-2 small low-frequency earthquakes per minute occurring at shallow depths beneath the summit caldera. There were some larger events at depths of a few kilometers. Small inflation and deflation occurred during the report week.
Sources: US Geological Survey Hawaiian Volcano Observatory (HVO), Associated Press
| Central Kamchatka (Russia)
| 56.056°N, 160.642°E
| Elevation 4754 m
During 22-29 August, seismicity was above background levels at Kliuchevskoi, with 3-8 earthquakes per day of magnitude less than 2.2 occurring at depths around 30 km. On 26 August at 2300 Strombolian activity was seen in the volcano's center crater. Volcanic bombs were hurled to ~200 m above the crater. There were 5-minute intervals between explosions. During 27-28 August, gas-and-steam plumes with minor amounts of ash rose 1.5-2 km above the volcano's crater and drifted SW. Kliuchevskoi remained at Concern Color Code Orange.
Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Associated Press
Piton de la Fournaise
| Reunion Island (France)
| 21.244°S, 55.708°E
| Elevation 2632 m
An eruption that began at Piton de la Fournaise on 22 August, stopped suddenly on 27 August at 2152. During the last 36 hours of activity, there was an increase in tremor intensity and lava emission. Afterwards, numerous long-period earthquakes were recorded.
Sources: Observatoire Volcanologique du Piton de la Fournaise (OVPF), News.com.au - News Limited
| 19.023°N, 98.622°W
| Elevation 5393 m
Aerial photography taken on 25 August revealed no external lava dome in Popocatépetl crater. On 28 August the number of low-level emissions increased in comparison to previous days. On 29 August at 1330 a low-density ash emission rose to ~1.5 km above the crater and drifted W. There were no reports of ash fall in villages near the volcano. This event was accompanied by episodes of high-frequency and low-amplitude tremor. By 1 September the number of emissions returned to levels recorded prior to the increase.
Source: Centro Nacional de Prevencion de Desastres (CENAPRED)
| New Britain (Papua New Guinea)
| 4.271°S, 152.203°E
| Elevation 688 m
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 (RVO)
| 16.72°N, 62.18°W
| Elevation 915 m
Activity at Soufrière Hills remained at low levels during 22-29 August. No changes or growth occurred at the lava dome. Small changes occurred in the 12 July collapse scar, with new fumaroles opening to the SE of the main explosion crater towards the upper Tar River Valley. Blue haze visible N of the volcano on 25 August and a strong sulfur smell were caused by the passage of a weather system and did not reflect an activity increase.
Source: Montserrat Volcano Observatory (MVO)
| 1.467°S, 78.442°W
| Elevation 5023 m
During 27 August to 1 September, volcanic block and ash emissions continued at Tungurahua. Ash plumes rose to a maximum height of ~4 km above the volcano. The plumes primarily drifted W and SW, depositing ash in several towns including Cotaló, Pillate, Cevallos, Guaranda, Guanujo, Riobamba, and Quero. An emission on 27 August at 1350 deposited ash in Ambato ~40 km NW of the volcano and caused flight restrictions to and from the airport there.
Sources: Instituto Geofísico-Escuela Politécnica Nacional (IG), Washington Volcanic Ash Advisory Center (VAAC), Agence France-Presse (AFP), El Comercio
Criteria & Disclaimers
The Weekly Volcanic Activity Report does not necessarily include all volcanic activity that occurred on Earth during the week. More than a dozen volcanoes globally have displayed more-or-less continuous eruptive activity for decades or longer, and such routine activity is typically not reported here. Moreover, Earth's sea-floor volcanism is seldom reported even though in theory it represents the single most prolific source of erupted material. The Weekly Volcanic Activity Report summarizes volcanic activity that meets one or more of the following criteria:
- A volcano observatory raises or lowers the alert level at the volcano.
- A volcanic ash advisory has been released by a volcanic ash advisory center (VAAC) stating that an ash cloud has been produced from the volcano.
- A verifiable news report of new activity or a change in activity at the volcano has been issued.
- Observers have reported a significant change in volcanic activity. Such activity can include, but is not restricted to, pyroclastic flows, lahars, lava flows, dome collapse, or increased unrest.
Volcanoes are included in the "New Activity/Unrest" section of the Weekly Volcanic Activity Report if the activity occurs after at least 3 months of quiescence. Once a volcano is included in the "New Activity/Unrest" section, updates will remain in that section unless the activity continues for more than 1 month without escalating, after which time updates will be listed in the "Continuing Activity" section. Volcanoes are also included in the "New Activity/Unrest" section if the volcano is undergoing a period of relatively high unrest, or increasing unrest. This is commonly equal to Alert Level Orange on a scale of Green, Yellow, Orange, Red, where Red is the highest alert. Or alert level 3 on a scale of 1-4 or 1-5.
It is important to note that volcanic activity meeting one or more of these criteria may occur during the week, but may not be included in the Weekly Volcanic Activity Report because we did not receive a report.
1. The Weekly Volcanic Activity Report is intended to provide timely information about global volcanism on a weekly basis. Consequently, the report is generated rapidly by summarizing volcanic reports from various sources, with little time for fact checking. The accuracy of the Weekly Volcanic Activity Report is dependent upon the quality of the volcanic activity reports we receive. Reports published in the Bulletin of the Global Volcanism Network are monthly, and more carefully reviewed, although all of the volcanoes discussed in the Weekly Volcanic Activity Report are not necessarily reported in the Bulletin. Because of our emphasis on rapid reporting on the web we have avoided diacritical marks. Reports are updated on the Weekly Volcanic Activity Report web page as they are received, therefore information may be included regarding events that occurred before the current report period.
2. Rapidly developing events lead to coverage that is often fragmentary. Volcanoes, their eruptions, and their plumes and associated atmospheric effects are complex phenomena that may require months to years of data analysis in order to create a comprehensive summary and interpretation of events.
3. Preliminary accounts sometimes contain exaggerations and "false alarms," and accordingly, this report may include some events ultimately found to be erroneous or misleading.
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