Activity for the week of 21 December-27 December 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
| 1.22°N, 77.37°W
| Elevation 4276 m
INGEOMINAS reported that activity continued at Galeras during 21-27 December, with steam rising from the main crater and two craters to the N and SW (Paisita and Chavas, respectively). The Alert Level remains at III (Yellow; "changes in the behavior of volcanic activity").
Source: Servicio Geológico Colombiano (SGC)
| Sulawesi (Indonesia)
| 1.358°N, 124.792°E
| Elevation 1580 m
According to a news article, three explosions from the Tompaluan crater, in the saddle between the Lokon-Empung peaks were recorded by the CVGHM on 27 December. CVGHM recorded 23 deep volcanic tremors and 40 shallow volcanic tremors. Residents and tourists were not permitted within a 2.5 km radius of the crater. Based on visual and seismic observations during 27-28 December, the Alert Level remained at 3 (on a scale of 1-4). The Darwin VAAC reported a low-level eruption on 27 December based on media reports.
Sources: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM), Darwin Volcanic Ash Advisory Centre (VAAC), The Jakarta Post
| 1.467°S, 78.442°W
| Elevation 5023 m
IG reported that increased seismicity from Tungurahua was detected during 21-27 December. On 22 December ash plumes rose 500 m above the crater and drifted 2 km W. Ashfall was reported in Baños, Vazcún, and Manzano. One explosion at 0850 generated two small pyroclastic flows that descended the Achupashal and Hacienda drainages. Gas-and-ash plumes rose 4 km a.s.l. and drifted NE. On 23 December ash and gas emissions continued and at night Strombolian activity was observed with blocks rising 500 m above the crater. Ashfall was reported in Cahuají, Manzano, and Choglontus. On 24 December roaring noises were heard and ashfall in Cahuají, Manzano, and Choglontus was reported. An ash plume rose 500 m above the crater and drifted W and SW with ashfall reported in Manzano.
Source: Instituto Geofísico-Escuela Politécnica Nacional (IG)
| 15.05°N, 42.18°E
| Elevation 191 m
An eruption from the northern part of the Zubair Group continued during 21-27 December. MODIS imagery from NASA's satellites on 22 December showed a plume, possibly containing ash, rising from what was thought to be a submarine eruption. Imagery acquired on 23 December from the Advanced Land Imager (ALI) on NASA's EO-1 satellite showed a new island at the location with a plume rising from it, roughly 500 m N of Rugged Island and more than 500 m in diameter. The island was not present in a similar image acquired on 24 October 2007.
Source: NASA Earth Observatory
| Kyushu (Japan)
| 31.593°N, 130.657°E
| Elevation 1117 m
Based on information from JMA, the Tokyo VAAC reported that during 21-27 December 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 E, SE, S, and NE. Satellite imagery on 23 December showed ash emissions that later dissipated. On 27 December observations from satellite images and a pilot report showed an ash plume that rose to an altitude of 3.7 km (12,000 ft) a.s.l. and drifted 9 km E.
Source: Tokyo Volcanic Ash Advisory Center (VAAC)
| 14.473°N, 90.88°W
| Elevation 3763 m
INSIVUMEH reported that during 21-27 December explosions from Fuego generated ash plumes that rose 200-800 m above the crater; the plumes drifted 10-12 km W, NW, SW, and S during 21-23 and 26-27 December. During 21-23 and 26-27 December explosions generated shock waves and rumbling sounds that were detected 12 km away. House windows and roofs vibrated in nearby villages on 27 December. Incandescence emanated from the crater at night, and avalanches traveled SW into the Taniluyá and Ceniza drainages, and S in the Santa Teresa drainage. Based on satellite observations, the Washington VAAC reported that a gas plume with possible ash drifted 9 km S on 24 December.
Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH), Washington Volcanic Ash Advisory Center (VAAC)
| 27.73°N, 18.03°W
| Elevation 1500 m
Instituto Geográfico Nacional (IGN) reported that during 21-27 December the submarine eruption continued S of El Hierro Island. The mean amplitude of the tremor signal remained stable during the week. Twelve seismic events were located during this period, most of them offshore, both to the N and S of the island, at depths between 12 and 26 km with a maximum magnitude of 2.8. GPS deformation data analyses showed stability in the horizontal components and trends to stability in the vertical component.
Source: Instituto Geográfico Nacional (IGN)
| 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 December and indicated that possible ash plumes rose to an altitude of 4.1 km (13,500 ft) a.s.l. Satellite imagery showed a thermal anomaly on the volcano on 21 December and a gas-and-steam plume with possible ash that drifted 40 km S on 20 December. The Aviation Color Code remained at Orange.
Based on information from KEMSD and satellite imagery, the Tokyo VAAC reported that on 26 December an eruption produced a plume that rose to an altitude of 5.2 km (17,000 ft) a.s.l. The altitude was based on seismic analysis.
Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo Volcanic Ash Advisory Center (VAAC)
| Hawaiian Islands (USA)
| 19.421°N, 155.287°W
| Elevation 1222 m
During 21-27 December, HVO reported that the lava lake circulated and periodically rose and fell in the deep pit within Kilauea's Halema'uma'u Crater, remaining below the inner ledge (75 m below the crater floor). Almost daily measurements indicated that the gas plume from the vent continued to deposit variable amounts of ash and fresh spatter nearby. On 22 December the SW vent wall collapsed into the lake, ejected lava onto the inner ledge, and caused an increased amount of ash in the plume.
Incandescence was visible from small spatter cones on the E and S edges of the Pu'u 'O'o crater floor. Pahoehoe lava flows, that were 300-400 m wide and fed by lava tubes from the fissure, continued to be active about 6.8 km SE of Pu'u 'O'o and entered the ocean W of Ka'ili'ili. During 25-26 December the tube appeared to be more robust and less surface flow activity was reported. Small plumes were observed from the ocean entry during 22-24 December and infrequent weak plumes were observed during 25-26 December. On 27 December a breakout of lava flows were visible on the pali (a fault scarp).
Source: US Geological Survey Hawaiian Volcano Observatory (HVO)
| Eastern Kamchatka (Russia)
| 55.131°N, 160.32°E
| Elevation 2334 m
KVERT reported moderate seismic activity at Kizimen during 16-23 December. Satellite images showed a daily thermal anomaly and a gas-and-steam plume that drifted 65 km S on 20 December. Video observations showed a gas-and-steam plume that rose about 3.5-4 km a.s.l. on 27 December. A large lava flow on the NE and E flanks continued to effuse. The Aviation Color Code remained at Orange. Based on analyses of satellite imagery and information from KVERT, the Tokyo VAAC reported that on 24 December an ash plume rose to an altitude of 5.2 km (17,000 ft) a.s.l. and drifted NW.
Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo Volcanic Ash Advisory Center (VAAC)
| 19.023°N, 98.622°W
| Elevation 5393 m
CENAPRED reported that during 21-27 December steam-and-gas emissions rose from Popocatépetl; the plumes contained small amounts of ash during 22-24 December. On 21 December a bluish gas plume was observed and during 22-23 December ash plumes rose 0.9-1 km above the crater. Crater incandescence was observed at night during 26-27 December.
Source: Centro Nacional de Prevencion de Desastres (CENAPRED)
| 40.59°S, 72.117°W
| Elevation 2236 m
Based on seismicity during 21-26 December, 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. Small incandescent explosions were observed at night during 21-24 December. Plumes observed with a web camera during 22-23 December rose 1-2.5 km above the crater and 5 km above the crater on 26 December. Satellite images showed ash plumes drifting 20-250 km E, SE, SW, NW, and NNE during 21-26 December. Ash spread 140 km NW and 200 km NNW on 23 December, ash scattered 55 km SE on 25 December, and 100 km N and 200 km ESE on 26 December. 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 moderate seismic activity from Shiveluch was detected during 16-23 December and a large thermal anomaly over the volcano was observed in satellite imagery.
Seismic data suggested that possible ash plumes rose to an altitude of 5 km (17,400 ft) a.s.l. Gas-and-steam plumes containing ash drifted 250 km S during 19-20 December. Explosions produced ash plumes that rose to an altitude of 6 km (19,700 ft) a.s.l. on 19 December. Ground-based observers noted that a viscous lava flow continued to effuse in the crater formed during a 2010 eruption. Moderate fumarolic activity at the lava dome was observed during 18-21 December; cloud cover prevented observations on the other days. The Aviation Color Code level remained at Orange.
Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
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.
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