Activity for the week of 21 September-27 September 2011
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
| 27.73°N, 18.03°W
| Elevation 1500 m
Instituto Geográfico Nacional (IGN) reported more than 900 new seismic events at Hierro during 20-26 September, five of them felt by residents. The maximum magnitude recorded was 3.4. The total number of located events had reached more than 8,100 since the anomalous activity began on 16 July. The rates of both GPS deformation and seismic energy release had significantly increased during the previous seven days. On 23 September, the Canarian Autonomous Government raised the Alert Code to Yellow.
Source: Instituto Geográfico Nacional (IGN)
| Flores Island (Indonesia)
| 8.542°S, 122.775°E
| Elevation 1703 m
CVGHM raised the Alert Level for Lewotobi Lakilaki, one of two stratovolcanoes composing Lewotobi, to 2 (on a scale of 1-4) on 22 September due to increased seismicity since 17 September and visual observations. Although no significant changes in the volcano were observed, diffuse white plumes rose 15 m above the crater. Visitors and residents were prohibited from going within a 1-km radius of Lewotobi Lakilaki.
Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)
| 19.023°N, 98.622°W
| Elevation 5393 m
During 21-25 September CENAPRED reported steam-and-gas emissions from Popocatépetl. An explosion on 26 September ejected incandescent fragments and produced an ash plume that rose 2.5 km above the crater. Following the explosion, a series of 11 gas-and-steam plumes containing small amounts of ash rose from the crater.
Source: Centro Nacional de Prevencion de Desastres (CENAPRED)
| Kyushu (Japan)
| 31.593°N, 130.657°E
| Elevation 1117 m
Based on information from JMA, the Tokyo VAAC reported that during 21-27 September explosions from Sakura-jima produced plumes that rose to altitudes of 1.5-2.7 km (5,000-9,000 ft) a.s.l. and drifted SE, S, and W. On 22 September a pilot observed an ash plume that rose to an altitude of 1.8 km (6,000 ft) a.s.l. and drifted SE.
Source: Tokyo Volcanic Ash Advisory Center (VAAC)
| Komba Island (Indonesia)
| 7.791°S, 123.585°E
| Elevation 633 m
Based on analyses of satellite imagery, the Darwin VAAC reported that during 21-24 September ash plumes from Batu Tara rose to an altitude of 2.1 km (7,000 ft) a.s.l. and drifted 37-65 km W, WNW, and NW.
Source: Darwin Volcanic Ash Advisory Centre (VAAC)
| Chuginadak Island (USA)
| 52.825°N, 169.944°W
| Elevation 1730 m
AVO reported that during 20-21 September no observations of elevated surface temperatures or ash emissions from Cleveland were visible in partly cloudy satellite images. Clouds obscured views on 22 September. Elevated surface temperatures were observed in satellite images during 23-24 September, suggesting that the lava dome eruption was continuing. On 25 September AVO noted that elevated surface temperatures were not observed in several clear views of the volcano by satellite during the previous 24-hour period. Cloud cover prevented observations on 26 September.
Source: US Geological Survey Alaska Volcano Observatory (AVO)
| Halmahera (Indonesia)
| 1.693°N, 127.894°E
| Elevation 1229 m
Based on analyses of satellite imagery, the Darwin VAAC reported that on 27 September ash plumes from Dukono rose to an altitude of 2.1 km (7,000 ft) a.s.l. and drifted 75 km NW and NE.
Source: Darwin Volcanic Ash Advisory Centre (VAAC)
| Eastern Kamchatka (Russia)
| 54.049°N, 159.443°E
| Elevation 1513 m
KVERT reported that seismic activity continued at a moderate level at Karymsky during 16-23 September and indicated that possible ash plumes rose to altitudes of 5-6 km (16,400-19,700 ft) a.s.l. during 16-17 September. A thermal anomaly was detected in satellite imagery during 16, 18, and 20 September. The Aviation Color Code remained at Orange.
Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
| Hawaiian Islands (USA)
| 19.421°N, 155.287°W
| Elevation 1222 m
During 21-27 September, HVO reported that the lava lake circulated and periodically rose and fell in the deep pit within Kilauea's Halema'uma'u crater. Almost daily measurements indicated that the gas plume from the vent continued to deposit variable amounts of ash and occasionally fresh spatter nearby.
At the E rift zone, lava in the W lava lake in Pu'u 'O'o Crater fed a series of lava flows that traveled down the W flank of Pu'u 'O'o during 20-21 September. At about 0225 on 21 September activity in the crater and overflows to the W suddenly decreased, as lava broke through the upper E flank of Pu'u 'O'o, bypassing the crater. The new fissure fed a channelized 'a'a lava flow that advanced rapidly downslope 2.5 km SE. A second flow to the W of the first began the next day. In addition, a small pad of lava actively refilled the bottom of the drained E lava lake and small flows were barely active at the W edge of Pu'u 'O'o Crater. The channelized 'a'a lava flow reached 3.7 km long on 23 September and then stalled within the Kahauale'a Natural Area Reserve. Most of the active lava spread S and W of Pu'u Halulu (1.3 km NE of Pu'u 'O'o) during 23-27 September. Minor lava activity resumed within Pu'u 'O'o Crater with short lava flows issuing from the base of the E wall on 25 September and from the W wall base during 25-26 September. The crater floor of Pu'u 'O'o slowly subsided. Lava activity resumed within the E lake on 26 September. The floor of the crater continued to subside during 26-27 September, opening up cracks in the N crater floor.
Source: US Geological Survey Hawaiian Volcano Observatory (HVO)
| Eastern Kamchatka (Russia)
| 55.131°N, 160.32°E
| Elevation 2334 m
KVERT reported that during 16-23 September volcanic tremor magnitude at Kizimen continued to increase; 1,400-1,600 earthquakes were recorded daily. A thermal anomaly on the volcano was detected in satellite images. Lava on the E flank continued to flow and video images showed strong fumarolic activity. The Aviation Color Code remained at Orange.
Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
| 40.59°S, 72.117°W
| Elevation 2236 m
Based on seismicity during 21-26 September, OVDAS-SERNAGEOMIN reported that the eruption from the Cordón Caulle rift zone, part of the Puyehue-Cordón Caulle volcanic complex, continued at a low level. Plumes observed by an area camera rose 3-5 km above the crater during 21-23 and 25 September and were visible in satellite images drifted 30-300 km NE, E, and SE during 21-26 September. The Alert Level remained at Red.
Source: Servicio Nacional de Geología y Minería (SERNAGEOMIN)
| Central Kamchatka (Russia)
| 56.653°N, 161.36°E
| Elevation 3283 m
KVERT reported that seismic activity at Shiveluch was moderate during 16-23 September. A thermal anomaly on the volcano was also observed in satellite imagery on 15 and 18 September. Ground-based observers noted fumarolic activity during 18-20 September. The Aviation Color Code remained at Orange.
Based on information from KEMSD, the Tokyo VAAC reported that on 24 September an eruption produced a plume that rose to an altitude of 6.4 km (21,000 ft) a.s.l. and drifted E. Subsequent images that day showed that the ash had dissipated.
Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo Volcanic Ash Advisory Center (VAAC)
| 16.72°N, 62.18°W
| Elevation 915 m
MVO reported that during 16-23 September activity at the Soufrière Hills lava dome was at a low level. On 19 September a pyroclastic flow occurred from the W side of the lava dome. The Hazard Level remained at 3.
Source: Montserrat Volcano Observatory (MVO)
News Feeds and Google Placemarks
The RSS (Really Simple Syndication) feed is identical to the Weekly Volcanic Activity Report minus some features including the header information (latitude and longitude and summit elevation), the Geologic Summary, and a link to the volcano's page from the Global Volcanism Program. Each volcano report includes a link from the volcano's name back to the more complete information in the Weekly Volcanic Activity Report on the Smithsonian website.
The CAP (Common Alerting Protocol) feeds are XML files specifically formatted for disaster management. They are similar in content to the RSS feed, but contain no active links.
A Google Earth network link for the Weekly Volcanic Activity Report can be loaded into the free Google Earth software, and in turn will load placemarks for volcanoes in the current weekly report. Placemark balloons include the volcano name, report date, report text, sources, and links back to the GVP volcano page for that volcano and to the complete Weekly Report for that week.
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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RSS and CAP Feeds
An RSS (Really Simple Syndication) feed for the Weekly Volcanic Activity Report first made available on 5 March 2008 can be utilized with the aid of various free downloadable readers. The report content of the news feed is identical to the Weekly Volcanic Activity Report minus some features including the header information (latitude and longitude and summit elevation), the Geologic Summary, and a link to the volcano's page from the Global Volcanism Program. Each volcano report includes a link from the volcano's name back to the more complete information in the Weekly Volcanic Activity Report on the Smithsonian website. On 12 March 2009, GeoRSS tags were added so that the latitude and longitude for each volcano could be included with the feed.
At the end of each individual report is a list of the sources used. We would like to emphasize that the World Organization of Volcano Observatories (WOVO) website (http://www.wovo.org/) lists the regional volcano observatories that have the most authoritative data for many of these events.
CAP (Common Alerting Protocol) feeds are XML files specifically formatted for disaster management.
Google Earth Placemarks
A Google Earth network link for the Weekly Volcanic Activity Report was first made available on 1 April 2009. This file can be loaded into the free Google Earth software, and in turn will load placemarks for volcanoes in the current weekly report. Placemark balloons include the volcano name, report date, report text, sources, and links back to the GVP volcano page for that volcano and to the complete Weekly Report for that week.