Activity for the week of 1 July-7 July 2009
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
Manda Hararo
| Ethiopia
| 12.17°N, 40.82°E
| Elevation 600 m
A large sulfur dioxide plume and several thermal anomalies from Manda Hararo were detected in satellite imagery during 28-30 June. Thermal anomalies detected in satellite imagery indicated a surface lava flow in the Karbahi region. Karbahi is a graben area with numerous active faults, fissures, and basalt flows, NW of the center of the broad Manda Hararo volcanic complex. Preliminary data suggested that the eruption was larger than the previous eruption in August 2007. On 8 July, a scientist that visited the area reported fresh lava flows, an eruptive fissure that was about 5 km long, and gas emitting from multiple cones.
Sources: Simon Carn, Hawai'i Institute of Geophysics and Planetology (HIGP) Thermal Alerts Team, The Guardian News
Mayon
| Luzon (Philippines)
| 13.257°N, 123.685°E
| Elevation 2462 m
According to news articles, PHIVOLCS implemented increased monitoring of Mayon after a recent rise in seismicity. Incandescence in the crater and a slight increase in sulfur dioxide gas output over background levels were also noted. The Alert Level remained at 1 (on a scale of 0-5). The 7-km Extended Danger Zone (EDZ) on the SE flank and the 6-km Permanent Danger Zone (PDZ) in all other areas remained in effect.
Source: GMA News
San Miguel
| El Salvador
| 13.434°N, 88.269°W
| Elevation 2130 m
Servicio Nacional de Estudios Territoriales (SNET) reported that seismic amplitude from San Miguel increased for a period of time between 0500 and 1400 on 6 July. Seismicity remained elevated above background levels on 7 July.
Source: Servicio Nacional de Estudios Territoriales (SNET)
Sarychev Peak
| Matua Island (Russia)
| 48.092°N, 153.2°E
| Elevation 1496 m
SVERT reported that an intense thermal anomaly from Sarychev Peak was detected on satellite imagery during 1-6 July. Gas-and-steam plumes were seen almost daily and drifted 20-75 km NW, NE, and SE. Plumes rose to altitudes of 1.5-3 km (4,900-10,000 ft) a.s.l. during 4-5 July. No large ash explosions were noted after 16 June.
Source: Sakhalin Volcanic Eruption Response Team (SVERT)
Ongoing Activity
Aira
| Kyushu (Japan)
| 31.593°N, 130.657°E
| Elevation 1117 m
Based on information from JMA, the Tokyo VAAC reported that during 2-4 and 6-7 July explosions from Sakura-jima sometimes produced plumes that rose to altitudes of 2.1-2.7 km (7,000-9,000 ft) a.s.l. The plumes drifted N, NE, E, and SE.
Source: Tokyo Volcanic Ash Advisory Center (VAAC)
Batu Tara
| Komba Island (Indonesia)
| 7.791°S, 123.585°E
| Elevation 633 m
Based on analysis of satellite imagery, the Darwin VAAC reported that during 1-7 July ash plumes from Batu Tara rose to altitudes of 1.5-2.4 km (5,000-8,000 ft) a.s.l. and drifted 35-110 km W, NW, and N. A thermal anomaly was detected on 3 July.
Source: Darwin Volcanic Ash Advisory Centre (VAAC)
Chaiten
| Chile
| 42.833°S, 72.646°W
| Elevation 1122 m
SERNAGEOMIN reported that during 24 June-2 July unspecified activity from Chaitén's growing Domo Nuevo 1 and Domo Nuevo 2 lava-dome complex was occasionally observed, and seismicity had decreased. The Alert Level remained at Red. Based on analysis of satellite imagery and web camera views, the Buenos Aires VAAC reported that on 4 July an ash plume rose to an altitude of 2.1 km (7,000 ft) a.s.l. and drifted SE.
Sources: Servicio Nacional de GeologÃa y MinerÃa (SERNAGEOMIN), Buenos Aires Volcanic Ash Advisory Center (VAAC)
Dukono
| Halmahera (Indonesia)
| 1.693°N, 127.894°E
| Elevation 1229 m
Based on analysis of satellite imagery, the Darwin VAAC reported that on 5 and 7 July ash plumes from Dukono rose to an altitude of 2.4 km (8,000 ft) a.s.l. and drifted 65 km E and 85 km NE, respectively.
Source: Darwin Volcanic Ash Advisory Centre (VAAC)
Kilauea
| Hawaiian Islands (USA)
| 19.421°N, 155.287°W
| Elevation 1222 m
During 1-6 July, HVO reported that lava flowed SE from underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex through a lava tube system, reaching the Waikupanaha and Kupapa'u ocean entries. Thermal anomalies detected in satellite images and visual observations revealed active surface flows on the pali and on the TEB flow field.
A sequence of rockfalls within the cavity on the floor of Halema'uma'u crater began at 1338 on 30 June. The first rockfall was followed by a loud explosion, and produced a M 2.4 equivalent earthquake felt at HVO and the adjacent Jaggar Museum. The gas plume turned brown for several minutes. Several more rockfall signals were detected by the seismic network; two more were felt locally. Booming sounds also accompanied several of the rockfalls. Chunks of the vent rim fell into the cavity. By 1600, more than 30 rim-collapse events had been recorded by seismometers, with a few more occurring on 1 July. Seismic tremor amplitudes decreased by more than 50 percent. By 1800, the levels were at their lowest values since 30 August 2007. On 1 July, scientists observed rocky rubble within the vent and no incandescence. Sporadic gas jetting noises were heard coming from the vent.
During 1-2 July, a few areas of incandescence were seen in the vent by the web camera. During 2-4 July, scientists observed a small ponded lava surface and weak spattering deep within the vent. The sulfur dioxide emission rate at the summit remained elevated; measurements were 360 and 200 tonnes per day on 3 and 5 July, respectively. The 2003-2007 average rate was 140 tonnes per day.
Source: US Geological Survey Hawaiian Volcano Observatory (HVO)
Krakatau
| Indonesia
| 6.102°S, 105.423°E
| Elevation 155 m
Based on a pilot observation, the Darwin VAAC reported that on 3 July an ash plume from Anak Krakatau rose to an altitude below 3 km (10,000 ft) a.s.l. Ash was not detected on satellite imagery.
Source: Darwin Volcanic Ash Advisory Centre (VAAC)
Rabaul
| New Britain (Papua New Guinea)
| 4.271°S, 152.203°E
| Elevation 688 m
Based on analysis of satellite imagery, the Darwin VAAC reported that on 3 July an ash plume from Rabaul caldera's Tavurvur cone rose to an altitude of 4.3 km (14,000 ft) a.s.l. and drifted 45 km N. On 7 July, an ash plume rose to an altitude of 2.1 km (7,000 ft) a.s.l. and drifted less than 30 km SE.
Source: Darwin Volcanic Ash Advisory Centre (VAAC)
Santa Maria
| Guatemala
| 14.757°N, 91.552°W
| Elevation 3745 m
INSIVUMEH reported that on 2 July lahars descended the Nimá I and Nimá II rivers on the S flank of Santa MarÃa's Santiaguito lava dome complex, carrying tree branches and blocks 50-75 cm in diameter. The lahars were 15 and 20 m wide. On 6 July, explosions produced ash plumes that rose to altitudes of 2.8-3.2 km (9,200-10,500 ft) a.s.l. and drifted W.
Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)
Sheveluch
| Central Kamchatka (Russia)
| 56.653°N, 161.36°E
| Elevation 3283 m
KVERT reported that during 25 June-3 July seismic activity from Shiveluch was above background levels. Pyroclastic flows were noted on 25 and 26 June. Based on interpretations of seismic data, ash plumes possibly rose to an altitude of 8.1 km (26,600 ft) a.s.l. during 25-30 June, and steam-and-gas plumes with some ash content were emitted during the reporting period. Analysis of satellite imagery revealed a daily thermal anomaly over the lava dome and ash plumes that drifted 97 km NE on 26 June. The Level of Concern Color Code remained at Orange. Based on analysis of satellite imagery and information from KEMSD, the Tokyo VAAC reported that on 3 and 5 July eruptions produced plumes that rose to altitudes of 4.9-5.5 km (16,000-18,000 ft) a.s.l.
Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo Volcanic Ash Advisory Center (VAAC)
Suwanosejima
| Ryukyu Islands (Japan)
| 29.638°N, 129.714°E
| Elevation 796 m
Based on information from JMA, the Tokyo VAAC reported an explosion from Suwanose-jima on 6 July. Details of a possible resultant ash plume were not reported.
Source: Tokyo Volcanic Ash Advisory Center (VAAC)
Tungurahua
| Ecuador
| 1.467°S, 78.442°W
| Elevation 5023 m
The IG reported that inclement weather often prevented observations of Tungurahua during 1-7 July; steam-and-ash plumes rose 1 km above the summit and drifted WSW on 1 July. Ashfall was reported in areas to the SW on 2 July. During 2 and 5-7 July, lahars that descended SW and W drainages carrying blocks up to 40 cm in diameter.
Source: Instituto GeofÃsico-Escuela Politécnica Nacional (IG)
Ubinas
| Peru
| 16.355°S, 70.903°W
| Elevation 5672 m
Based on a pilot observation, the Buenos Aires VAAC reported that on 4 July an ash plume from Ubinas rose to altitudes of 6.7-9.1 km (22,000-30,000 ft) a.s.l. and drifted NE. Ash was not detected on satellite imagery.
Source: Buenos Aires Volcanic Ash Advisory Center (VAAC)
Criteria & Disclaimers
Criteria
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.
Disclaimers
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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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.
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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.
