Activity for the week of 11 February-17 February 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
| Honshu (Japan)
| 36.406°N, 138.523°E
| Elevation 2568 m
Based on information from JMA, the Tokyo VAAC reported that during 11-12 February eruptions from Asama produced plumes that rose to altitudes of 3-3.7 km (10,000-12,000 ft) a.s.l. and drifted NE, E, and SE. JMA reported that on 16 and 17 February eruptions produced colored plumes containing ash that rose to an altitude of 3 km (10,000 ft) a.s.l. and drifted E. Incandescence in the crater was seen on web cameras.
Sources: Japan Meteorological Agency (JMA), Tokyo Volcanic Ash Advisory Center (VAAC)
| Paramushir Island (Russia)
| 50.686°N, 156.014°E
| Elevation 1103 m
Based on analysis of satellite imagery and information from Yelizovo Airport, the Tokyo VAAC reported that on 11 February an ash plume drifted NE from Ebeko at an altitude of 0.6 km (2,000 ft) a.s.l. On 17 February, an ash plume drifted SW at an altitude of 1.2 km (4,000 ft) a.s.l.
Source: Tokyo Volcanic Ash Advisory Center (VAAC)
| 1.22°N, 77.37°W
| Elevation 4276 m
INGEOMINAS reported an explosive eruption from Galeras that began at 1910 on 14 February; the Alert Level was raised from III (Yellow; "changes in the behavior of volcanic activity") to I (Red; "imminent eruption or in progress"), on a scale of 4-1. An accompanying shock wave was detected in multiple areas, including in parts of Pasto (about 10 km E). The altitude of the resultant ash plume was not known nor observed on satellite images due to cloud cover. From about 1930 until 2030 ashfall, rain, and an odor of sulfur gas were reported on the slopes of the volcano as well as in Pasto. Ash deposits were mainly in areas to the E and as far away as 25 km. Seismicity returned at 1950 to similar levels recorded prior to the eruption and remained low. On 16 February, the Alert Level was lowered to II (Orange; "probable eruption in term of days or weeks"). During 16-17 February, small steam plumes rose to altitudes of 4.6-6.7 km (15,100-22,000 ft) a.s.l. and drifted SE, E, and NE.
According to news articles, authorities ordered the evacuation of about 8,000 people living on the slopes, but few went to evacuation shelters.
Sources: Servicio Geológico Colombiano (SGC), Agence France-Presse (AFP), Caracol Radio
| United States
| 60.485°N, 152.742°W
| Elevation 3108 m
AVO reported that during 10-17 February seismic activity at Redoubt was variable but remained elevated above background levels. Web camera views were often obscured by snow, clouds, or ice on the camera housing. On 10 February, scientists noted that the outflow stream on the W side of Drift Glacier was frozen.
Source: US Geological Survey Alaska Volcano Observatory (AVO)
| Kyushu (Japan)
| 31.593°N, 130.657°E
| Elevation 1117 m
Based on analysis of satellite imagery and pilot observations, the Tokyo VAAC reported that during 11-12 February ash plumes from Sakura-jima rose to altitudes of 1.2-1.5 km (4,000-5,000 ft) a.s.l.
Source: Tokyo Volcanic Ash Advisory Center (VAAC)
| Costa Rica
| 10.463°N, 84.703°W
| Elevation 1670 m
OVSICORI-UNA reported that during January, activity originating from Arenal's Crater C consisted of gas emissions, sporadic Strombolian eruptions, and occasional avalanches from lava-flow fronts that traveled down the SW flanks. Volcanic activity was at relatively low levels and few eruptions occurred. Acid rain and small amounts of ejected pyroclastic material affected the NE and SE flanks. Eruptions produced ash plumes that rose about 2.2 km (7,100 ft) a.s.l. Small avalanches of volcanic material traveled down several ravines. Crater D showed only fumarolic activity.
Source: Observatorio Vulcanologico y Sismologico de Costa Rica-Universidad Nacional (OVSICORI-UNA)
| Halmahera (Indonesia)
| 1.693°N, 127.894°E
| Elevation 1229 m
Based on analysis of satellite imagery, the Darwin VAAC reported that an ash plume from Dukono drifted SE at an altitude of 3 km (10,000 ft) a.s.l. on 11 February.
Source: Darwin Volcanic Ash Advisory Centre (VAAC)
| Eastern Kamchatka (Russia)
| 54.049°N, 159.443°E
| Elevation 1513 m
KVERT reported that seismic activity at Karymsky was above background levels during 6-9 February and at background levels during 10-13 February. Ash explosions produced plumes that rose to an altitude of 2.5 km (8,200 ft) a.s.l. Clouds prevented satellite observations. The Level of Concern Color Code remained at Orange.
Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
| Hawaiian Islands (USA)
| 19.421°N, 155.287°W
| Elevation 1222 m
HVO reported that during 11-17 February lava flowed SE from underneath Kilauea's Thanksgiving Eve Breakout (TEB) and rootless shield complex through a lava tube system, reaching the Waikupanaha and Waha'ula ocean entries. On most days, multiple explosions and spatter at the ocean entry were seen. On 11 February, geologists found a new littoral cone, on the edge of the bench, with a large crack running through it. Spatter on the cone and the bench behind it resulted from lava bubble bursts and steam jetting reported during the previous two days. A second crack between the cone and the sea cliff was also noted. The cracks suggested that the bench was slowly failing and did not collapse as reported a few days prior. Occasional incandescence originated from the Prince lobe, the flow that feeds the Waha'ula ocean entry. Thermal anomalies suggesting surface flows were noted on the coastal plain and on the pali.
The vent in Halema'uma'u crater continued to produce a predominantly white plume that drifted mainly SW; incandescence was intermittently seen from the vent. Small amounts of tephra, including Pele's hair and some spatter, were routinely collected. Infrared images taken during an overflight on 11 February revealed the development of a small spattering cone over the conduit that hosted a lava pond the previous week. Images taken on 14 February indicated that the conduit had mostly crusted over; a small, puffing vent was visible. The sulfur dioxide emission rate at the summit was 800 tonnes per day on 12 February, and 500 tonnes on 13 February; the 2003-2007 average rate was 140 tonnes per day.
Source: US Geological Survey Hawaiian Volcano Observatory (HVO)
| 19.023°N, 98.622°W
| Elevation 5393 m
CENAPRED reported that emissions of steam and gas from Popocatépetl were visible during 11-17 February; the plumes occasionally contained slight amounts of ash. On 13 February, a plume with low ash content rose to an altitude of 7.2 km (23,600 ft) a.s.l. and drifted NE at 2230; 95 minutes of increased seismicity followed.
Sources: Centro Nacional de Prevencion de Desastres (CENAPRED), Washington Volcanic Ash Advisory Center (VAAC)
| 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 during 13-14 February ash plumes from Rabaul caldera's Tavurvur cone rose to an altitude of 2.4 km (8,000 ft) a.s.l. and drifted SE and W. On 17 February, a low-level ash plume drifted SE.
Source: Darwin Volcanic Ash Advisory Centre (VAAC)
| 14.757°N, 91.552°W
| Elevation 3745 m
Based on analysis of satellite imagery, the Washington VAAC reported that on 12 February ash puffs from Santa María's Santiaguito lava dome complex drifted WSW and W. On 16 and 17 February, INSIVUMEH reported that explosions produced ash plumes that rose to altitudes of 2.7-3.3 km (8,900-10,800 ft) a.s.l. and drifted SW. Small pyroclastic flows on 16 February descended the SE flank and reached the Nima I river. On 17 February, incandescent avalanches were noted and fumarolic plumes drifted SW.
Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH), Washington Volcanic Ash Advisory Center (VAAC)
| Central Kamchatka (Russia)
| 56.653°N, 161.36°E
| Elevation 3283 m
KVERT reported that seismic activity at Shiveluch was above background levels during 6-13 February. Based on interpretations of seismic data, ash plumes likely rose to altitudes of 5.5 km (18,000 ft) a.s.l. Lava flows continued to be active on the S and N flanks. Analysis of satellite imagery revealed a thermal anomaly on the lava dome during 6 and 8-10 February; clouds prevented observations on the other days during the reporting period. The Level of Concern Color Code remained at Orange.
Based on information from KEMSD, the Tokyo VAAC reported that an eruption on 12 February produced a plume that rose to an altitude of 4.6 km (15,000 ft) a.s.l.
Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo Volcanic Ash Advisory Center (VAAC)
| Fox Islands (USA)
| 54.756°N, 163.97°W
| Elevation 2857 m
AVO reported that seismic activity from Shishaldin had returned to background levels in December 2008 and remained low. On 3 February, a weak thermal anomaly was detected on satellite imagery. The Aviation Color Code was lowered to Green and the Volcano Alert Level was lowered to Normal on 11 February.
Source: US Geological Survey Alaska Volcano Observatory (AVO)
| 16.72°N, 62.18°W
| Elevation 915 m
MVO reported that during 6-13 February activity from the Soufrière Hills lava dome was at a low level. Two rockfalls were detected and seismicity was low. On 13 February, one small pyroclastic flow that originated in a gully on the N side of the lava dome traveled less than 1 km. The Hazard Level remained at 4.
Source: Montserrat Volcano Observatory (MVO)
| 1.467°S, 78.442°W
| Elevation 5023 m
The IG reported that although visual observations of Tungurahua were occasionally limited due to cloud cover; gas-and-ash plumes were seen and rose to altitudes of 5.5-7.5 km (18,000-24,600 ft) a.s.l. during 11-17 February. Plumes drifted W, NE, E, and SE. On 11 February, small lahars descended multiple gorges to the NW and S. Incandescence in the crater was seen at night on 11 and 12 February, and roaring was heard on 12 and 16 February. Ashfall was reported in areas to the SW on 12 February and to the N on 14 February. An explosion on 16 February that vibrated windows was followed by ash emissions that generated a plume to an altitude of 8 km (26,200 ft) a.s.l. The plume drifted W.
Source: Instituto Geofísico-Escuela Politécnica Nacional (IG)
| 16.355°S, 70.903°W
| Elevation 5672 m
INGEMMET reported that although cloud cover occasionally prevented visual observations of Ubinas, steam and steam-and-ash plumes were seen during 11-16 February and rose to altitudes of 5.7-6.5 km (18,700-21,300 ft) a.s.l. The plumes drifted NE, N, W, and SW.
Source: Instituto Geológico Minero y Metalúrgico (INGEMMET)
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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