Smithsonian / USGS Weekly Volcanic Activity Report
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, these notices are preliminary and subject to change as events are studied in more detail. This is not a comprehensive list of eruptions during the week, but rather a summary of activity that meet selected criteria. Carefully reviewed, detailed reports are published monthly in the Bulletin of the Global Volcanism Network. 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.
Friday, March 04, 2011 6:45 PM
INGV-CT reported that on 16 February an explosive sequence, presumably from Etna's NE Crater, was detected on 16 February during the late evening. Cloud cover made direct observations difficult. On 18 February the thermal monitoring camera at Montagnola (EMOT) recorded anomalies from the pit crater located on the lower E flank of SE Crater cone. At the same time, the visible-light camera at Montagnola (EMOV) showed intermittent incandescence indicating Strombolian activity, and the seismic network recorded a rapid increase in the volcanic tremor amplitude. This eruptive episode lasted about 11 hours and produced pulsating lava fountains. Lava flows traveled E, following the same path as that of the 12-13 January event, in the direction of the Valle del Bove. Light ashfall occurred on the SW flank of the volcano.
Source: Istituto Nazionale di Geofisica e Vulcanologia Sezione di Catania (INGV-CT)
Friday, March 04, 2011 6:45 PM
INSIVUMEH reported that during 16-17 and 20-22 February explosions from Fuego produced ash plumes that rose 300-800 m above the crater. Some plumes drifted E. Incandescent material was ejected as high as 100 m above the crater. Avalanches traveled E as well as SW, descending the Taniluyá, Santa Teresa, Ceniza, and Trinidad drainages.
Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)
Friday, March 04, 2011 6:45 PM
Based on reports from JMA, the Tokyo VAAC reported that on 18 February an explosion from Shinmoe-dake (Shinmoe peak), a stratovolcano of the Kirishima volcano group, produced a plume that rose to an altitude of 4.6 km (15,000 ft) a.s.l. and drifted S. A pilot reported that an ash plume rose to an altitude of 5.5 km (18,000 ft) a.s.l. and drifted E. The next day, satellite imagery showed that the ash had dissipated. According to a news article on 17 February, officials recommended that more than 2,500 residents should evacuate their homes due to potential lahar activity from heavy rain. An official noted that 63 people in Miyakonojo (30 km SE) had already moved to evacuation shelters.
Sources: Tokyo Volcanic Ash Advisory Center (VAAC), Stuff
Friday, March 04, 2011 6:45 PM
INSIVUMEH reported that during 16-17 February explosions from Santa María's Santiaguito lava dome complex produced ash plumes that rose 800 m above Caliente dome and drifted S and SW. Avalanches traveled S, and ashfall was reported in Palajunoj, on the SW flank. According to the Washington VAAC, ash plumes were observed in satellite imagery drifting more than 10 km SSW. During 18-19 February, thermal anomalies were detected in satellite imagery. An ash plume drifted 25 km W on 18 February and again W at an altitude of 3.4 km (11,000 ft) a.s.l. on 19 February. INSIVUMEH reported that during 20-21 February activity was low. Explosions produced ash plumes that rose up to 500-900 m above Caliente dome. On 21 February a few avalanches and pyroclastic flows accompanied the explosions. Incandescent avalanches originated from the top of Caliente dome on 22 February.
Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH), Washington Volcanic Ash Advisory Center (VAAC)
Friday, March 04, 2011 6:45 PM
INGV-CT reported that on 17 February a series of strong explosions from the northernmost vent of Stromboli's summit area led to the accumulation of hot scoriaceous material on the external N flank of the crater. Activity continued at elevated levels from two vents in the northern portion of the crater terrace through 23 February.
Source: Istituto Nazionale di Geofisica e Vulcanologia Sezione di Catania (INGV-CT)
Friday, March 04, 2011 6:45 PM
During 17-20 February, PHIVOLCS reported that up to three daily volcanic earthquakes at Bulusan were detected by the seismic network. Cloud cover mostly prevented observations of the summit area, although steam rose from NW thermal vents on 19 February. An explosion on 21 February produced a gray ash plume that rose 3 km above the crater and drifted SW. Rumbling sounds were heard up to 10 km away in the town of Juban (NW). The event was recorded by the seismic network as an explosion-type earthquake lasting for about 19 minutes. Field investigations confirmed ash deposits in the towns of Irosin (up to 5 mm), 8 km SSW, and Bulan (up to 3 mm), 22 km SW. Traces of ashfall were also reported in the municipalities of Juban and Magallanes (24 km WNW), and in Masbate City (70 km SW), Masbate. According to news articles, about 2,000 people evacuated. During 21-22 February 16 volcanic earthquakes were detected by the seismic network. The Alert Level remained at 1 (on a scale of 0-5).
Sources: Philippine Institute of Volcanology and Seismology (PHIVOLCS), Xinhua
Friday, March 04, 2011 6:45 PM
Based on analyses of satellite imagery, the Darwin VAAC reported that during 16-17 February an ash plume from Dukono rose to an altitude of 3 km (10,000 ft) a.s.l. and drifted 150-185 km SW and W.
Source: Darwin Volcanic Ash Advisory Centre (VAAC)
Friday, March 04, 2011 6:45 PM
KVERT reported that moderate seismic activity was detected at Karymsky during 11-18 February. Seismic data indicated that possible ash plumes rose to an altitude of 4 km (13,100 ft) a.s.l. Satellite imagery showed a daily thermal anomaly and ash plumes that drifted 30 km NE on 16 February. The Aviation Color Code remained at Orange.
Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
Friday, March 04, 2011 6:45 PM
During 16-22 February, activity continued from the summit caldera and east rift zone. At the summit caldera, the level of the circulating lava-pool surface in the deep pit within Halema'uma'u crater fluctuated between 70 and 125 m below the crater floor. Nighttime incandescence was visible from the Jaggar Museum on the NW caldera rim. A plume from the vent drifted in multiple directions and deposited ash and fresh spatter nearby.At the east rift zone, two branches of the 29 November lava flow (a lava tube breach at 366 m elevation) produced scattered surface flows on the pali and coastal plain. In Pu'u 'O'o crater, lava effused from a cone on the NE portion of the crater floor and from a vent in the E crater wall during most of 16-18 February, covering a large portion of the crater floor. After the lava effusion ceased, incandescence emanated from the cone and vent.
Source: US Geological Survey Hawaiian Volcano Observatory (HVO)
Friday, March 04, 2011 6:45 PM
KVERT reported that during 11-18 February seismicity from Kizimen was high but variable, and many shallow volcanic earthquakes as well as volcanic tremor continued to be detected. Satellite images showed a bright thermal anomaly over the volcano daily. During 12-17 February ash plumes drifted more than 170 km E. The Aviation Color Code remained at Orange.The Tokyo VAAC reported that on 22 February a possible eruption detected in satellite imagery produced a plume that rose to an altitude of 2.7 km (9,000 ft) a.s.l. and drifted E. Subsequent notices stated that ash emissions had continued then dissipated later that day.
Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo Volcanic Ash Advisory Center (VAAC)
Friday, March 04, 2011 6:45 PM
Based on SIGMET notices, the Buenos Aires VAAC reported that on 17 February an ash plume from Planchón-Peteroa rose to altitudes of 3-4.3 km (10,000-14,000 ft) a.s.l. and drifted SE.
Source: Buenos Aires Volcanic Ash Advisory Center (VAAC)
Friday, March 04, 2011 6:45 PM
Based on information from JMA, the Tokyo VAAC reported that during 16-17 and 19-22 February explosions from Sakura-jima sometimes produced plumes that rose to altitudes of 1.8-2.4 km (6,000-8,000 ft) a.s.l. Some plumes drifted W, SW, and ESE. During 21-22 February, pilots reported that ash plumes rose to altitudes of 2.4-2.7-3 km (8,000-9,000 ft) a.s.l.
Source: Tokyo Volcanic Ash Advisory Center (VAAC)
Friday, March 04, 2011 6:45 PM
KVERT reported that moderate seismic activity was detected at Shiveluch during 11-18 February. A thermal anomaly over the lava dome was observed daily in satellite imagery. Gas and steam activity was observed on 13 and 16 February. The Aviation Color Code remained at Orange. The Tokyo VAAC reported that on 22 February a possible eruption detected in satellite imagery produced a plume that rose to an altitude of 3.4 km (11,000 ft) a.s.l. and drifted NE. Subsequent notices that day stated that ash had dissipated.
Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo Volcanic Ash Advisory Center (VAAC)
Friday, March 04, 2011 6:45 PM
MVO reported that on 15 February clear views of the Soufrière Hills lava dome allowed scientists to conduct a thermal survey, the first since 2 December 2010, and compare the results to identify changes. A warmer area on the W side of the lava dome (Gages) had moved upslope. This area had been the source of a number of pyroclastic flows and rockfalls since February 2010. The second difference was the apparent increase in the number of fumaroles inside the collapse scar and around the 2006-2007 dome. One of the most obvious areas of increase was on the NE side of the lava dome. MVO also reported that in total 18 volcano-tectonic earthquakes from Soufrière Hills were detected in two swarms that occurred on 12 and 16 February. Brief clear views of the lava dome revealed no significant morphological changes. Fresh pyroclastic-flow deposits on the E side of the dome at the head of the Tar River valley were noted. The Hazard Level remained at 3.
Source: Montserrat Volcano Observatory (MVO)
Friday, March 04, 2011 6:45 PM
CVGHM reported that during 17-18 February brownish gray ash plumes from Tengger Caldera's Bromo cone rose 400-800 m above the crater and drifted ENE. Incandescent material was ejected 300 m above the crater and landed as far as 500 m away, and roaring and booming was heard. The Alert Level remained at 3 (on a scale of 1-4). Residents and tourists were not permitted within a 2-km-radius of the active crater.
Source: Center of Volcanology and Geological Hazard Mitigation (CVGHM)
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