Activity for the week of 10 May-16 May 2006
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
| Central Java (Indonesia)
| 7.54°S, 110.446°E
| Elevation 2910 m
CVGHM reported that on 11 May, gas plumes rose to ~600 m above Merapi (or 11,600 ft a.s.l.). Avalanches of incandescent material extended 200 m SE towards the Gendol River, and 1.5 km SW towards the Krasak River. Several small incandescent avalanches of volcanic material were visible from observatory posts. The new lava dome at the volcano's summit had grown to fill the gap between the 2001 lava flows and the 1997 lava flows on the W side of the summit. The lava dome reached a height above that of the 1997 lava flows. Seismicity was dominated by multi-phase earthquakes and signals associated with avalanches. On 13 May at 0940, the Alert Level was raised from 3 to 4, the highest level.
The Darwin VAAC reported that on 11 May an ash plume was visible on satellite imagery below 3.7 km (12,000 ft) a.s.l. An ash plume at an unknown height was visible on satellite imagery on 15 May.
According to news reports, after the Alert Level was raised to 4 on 13 May, about 4,500 people living near the volcano were evacuated. Intense activity occurred on 15 May, with pyroclastic flows traveling as far as 4 km to the W. By 16 May a total of about 22,000 people were evacuated; according to figures posted at the district disaster task force center about 16,870 people were evacuated from three districts in Central Java Province, and more than 5,600 others were evacuated from the Slemen district, a part of Yogyakarta Province. Activity decreased on 16 May. On 17 May pyroclastic flows traveled as far as 3 km. Local volcanologists reported that the lava dome continued to grow, but at a slower rate than during previous days.
Sources: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM), Darwin Volcanic Ash Advisory Centre (VAAC), Associated Press, Agence France-Presse (AFP), Reuters
| Costa Rica
| 10.463°N, 84.703°W
| Elevation 1670 m
On 10 May around 1000, a pyroclastic flow traveled down Arenal's N flank. An ash-and-gas cloud was produced that drifted SW.
Source: Observatorio Vulcanologico y Sismologico de Costa Rica-Universidad Nacional (OVSICORI-UNA)
| Central Kamchatka (Russia)
| 55.972°N, 160.595°E
| Elevation 2882 m
Following an explosive eruption at Bezymianny on 9 May, seismicity was at background levels on 10 May. In addition, fumarolic plumes were observed and lava flows probably extended from the lava dome. On 11 May the Concern Color Code at Bezymianny was reduced from Orange to Yellow. On 12 May, seismicity remained at background levels and gas-and-steam plumes were visible.
Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
| 1.22°N, 77.37°W
| Elevation 4276 m
INGEOMINAS reported that during 9-15 May, a partially solidified lava dome remained in Galeras' main crater. Seismicity and the sulfur-dioxide flux continued at low levels. Gas and sporadic ash emissions rose to low levels. Galeras remained at Alert Level 2 (likely eruption in days or weeks).
Source: Servicio Geológico Colombiano (SGC)
| Eastern Kamchatka (Russia)
| 54.049°N, 159.443°E
| Elevation 1513 m
During 5-12 May, eruptive activity continued at Karymsky. Based on interpretations of seismic data, ash plumes rose to a height of ~5.3 km (17,400 ft) a.s.l. A thermal anomaly was present on satellite data when the crater was visible. Ash plumes drifted SE. KVERT warned that activity from the volcano could affect nearby low-flying aircraft. Karymsky remained at Concern Color Code Orange.
Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
| Hawaiian Islands (USA)
| 19.421°N, 155.287°W
| Elevation 1222 m
During 15-16 May, lava from Kilauea continued to flow off of a lava delta into the ocean at the East Lae`apuki entry. No surface lava flows were visible on the Puluma pali fault scarp, as has been the case since 8 February. Kilauea's summit began to deflate on 14 May. On 16 May, inflation occurred that was accompanied by an abrupt drop in volcanic tremor at Kilauea's summit. Volcanic tremor reached moderate levels at Pu`u `O`o.
Source: US Geological Survey Hawaiian Volcano Observatory (HVO)
| 16.507°S, 168.346°E
| Elevation 1413 m
The Wellington VAAC reported that a slow moving plume from Lopevi reached a height of 3 km (10,000 ft) a.s.l. on 10 May. On 11 May, a plume rose to 4.6 km (15,000 ft) a.s.l. and trended SE. During 12-13 May, the plume height lessened to 3 km (10,000 ft) a.s.l. as the eruption vigor reportedly decreased. According to Vanuatu's National Disaster Office, a news article reported that on 15 May an eruption at Lopevi produced heavy ashfall extending to the neighboring islands of Ambrym and Paama.
Source: Wellington Volcanic Ash Advisory Center (VAAC)
| Eastern Java (Indonesia)
| 8.108°S, 112.922°E
| Elevation 3657 m
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 Volcanic Ash Advisory Centre (VAAC)
| 16.72°N, 62.18°W
| Elevation 915 m
During 5-12 May, the new lobe of the lava dome at Soufrière Hills that developed towards the S produced rockfalls that predominantly extended from the W to the SE. On the 12th, the lava dome volume was approximately 80 million cubic meters, having grown at an average rate of 8 cubic meters per second through April. Seismicity typical of this current growth phase was dominated by rockfall activity during the report period. The average sulfur-dioxide flux during the week was 702 metric tons per day.
Sources: Montserrat Volcano Observatory (MVO), Washington Volcanic Ash Advisory Center (VAAC)
| United States
| 46.2°N, 122.18°W
| Elevation 2549 m
Analysis of photographs revealed that a slab of rock approximately 50,000 cubic meters in volume was shed from the N margin of the growing spine at Mt. St. Helens sometime during 6-7 May. This activity probably coincided with a large seismic signal recorded on the night of 7 May. Rock-avalanche deposits extended a few hundred meters to the NE. The avalanche was accompanied by an ash cloud. The spine continued to grow during 10-15 May, producing rockfalls that intensified on the evening of 14 May. Incandescence was visible on satellite imagery. The volcano remained at Volcano Advisory (Alert Level 2); aviation color code Orange.
Source: US Geological Survey Cascades Volcano Observatory (CVO)
| 1.467°S, 78.442°W
| Elevation 5023 m
During 15-16 May, small-to-moderate explosions at Tungurahua produced plumes composed of gas, steam, and small amounts of ash. A news article reported that on 15 May blasts could be heard within 20 km of the volcano, and a moderate-to-large explosion was heard in nearby communities. On 16 May, a plume reached a height of ~2 km above the crater (or 23,000 ft a.s.l.) and drifted W.
Sources: Instituto Geofísico-Escuela Politécnica Nacional (IG), Washington Volcanic Ash Advisory Center (VAAC)
| 16.355°S, 70.903°W
| Elevation 5672 m
Based on information from significant meteorological advisories (SIGMET) and pilot reports, the Buenos Aires VAAC reported that ash emitted from Ubinas during 9-11 and 13-14 May rose to a maximum height of 7.3 km (24,000 ft) a.s.l.
Source: Buenos Aires Volcanic Ash Advisory Center (VAAC)
| New Britain (Papua New Guinea)
| 5.05°S, 151.33°E
| Elevation 2334 m
On 14 May, an ash plume from Ulawun of unknown height was visible on satellite imagery.
Source: Darwin Volcanic Ash Advisory Centre (VAAC)
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.