SI / 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.
AVO reported that during 7-8 September clear-weather satellite views of Cleveland showed no thermal anomalies or recent deposits on the flanks. The Volcano Alert Level and the Aviation Color Code were lowered to Unassigned. On 11 September, a thermal anomaly was observed in satellite imagery. The next day a possible ash plume seen in satellite imagery rose to the estimated altitude of 7.6 km (25,000 ft) a.s.l. and drifted E. The Volcano Alert Level and the Aviation Color Code were again raised to Advisory and Yellow, respectively. A thermal anomaly was again visible during 13-14 September.
On 13 September, SVERT reported that strong steam-and-gas activity from Ekarma continued. Ekarma does not have a seismic network; satellite image analysis and infrequent ground observations are the primary tool for monitoring many of the Kuril Islands volcanoes.
Source: Sakhalin Volcanic Eruption Response Team (SVERT)
KVERT reported that during 3-10 September seismic activity from Kliuchevskoi was above background levels and lava flowed down the SW and NW flanks. Satellite imagery analyses showed a large and intense daily thermal anomaly over the volcano. During 2-4 September ash plumes seen in satellite imagery drifted 150 km S and SW at an altitude of 6.5 km (21,300 ft) a.s.l. Phreatic bursts on the SW flank were observed on 5 September and Strombolian activity was seen during 5-7 September. Seismic data suggested that during 5-6 September ash plumes rose to an altitude of 6 km (19,700 ft) a.s.l. Based on analyses of satellite imagery, the Tokyo VAAC reported that a possible eruption on 12 September produced a plume that rose to an altitude of 7.6 km (25,000 ft) a.s.l. and drifted SE. On 13 September an ash plume rose to an altitude of 9.8 km (32,000 ft) a.s.l. and drifted NE according to information sent from the Yelizovo Airport (UHPP). Ash was seen in subsequent satellite images during 13-14 September. The Aviation Color Code level remained at Orange.
Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo Volcanic Ash Advisory Center (VAAC)
The Popayán Volcano Observatory (INGEOMINAS) reported increased activity from Nevado del Huila on 8 and 9 September. Pulses of tremor were associated with periodic emissions of gas, ash, and incandescent material observed with the Tafxnú and Maravillas web cameras. During 8-14 September plumes of steam and occasionally ash rose as high as 2 km above the summit. The Alert Level was raised to II (Orange; "probable eruption in term of days or weeks").
Source: Instituto Colombiano de Geología y Minería (INGEOMINAS)
SERNAGEOMIN reported that an overflight of Planchón-Peteroa on 7 September revealed that the explosions the day before were possibly phreato-magmatic in origin and similar to the explosions in 1991. Pulses of gas and ash had occurred every 40-60 seconds during the eruption. Plumes rose 200 m above the crater and ash mostly fell within 10 km to the E. During 10-13 September, plumes rising from the vent had progressively less ash and higher concentrations of water vapor. On 13 September, SERNAGEOMIN reported that petrographic and mineralogical studies of the ash indicated no juvenile components. The Alert Level remained at 4, Yellow.
Source: Servicio Nacional de Geología y Minería (SERNAGEOMIN)
INSIVUMEH reported that an eruption from Santa María's Santiaguito lava dome complex on 11 September generated two pyroclastic flows that traveled 3 km SW and deposited material in the Nimá II drainage. Ash plumes rose 1 km above the crater and drifted E and SE. On 13 September white plumes rose 100 m and drifted S.
Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)
CVGHM reported that during 8-11 September Sinabung emitted white-to-gray plumes that rose 30-100 m above the crater and generally drifted E. Deformation measurements during 8-14 September showed a slow rate of inflation. Based on analyses of satellite imagery and the CVGHM web camera, the Darwin VAAC reported that on 12 and 14 September ash plumes rose to altitudes of 4.3-4.6 km (14,000-15,000 ft) a.s.l. The Alert Level remained at 4 (on a scale of 1-4).
Sources: Center of Volcanology and Geological Hazard Mitigation (CVGHM), Darwin Volcanic Ash Advisory Centre (VAAC)
OVSICORI-UNA reported that during August activity originating from Arenal's Crater C consisted of gas emissions, sporadic Strombolian eruptions, and occasional avalanches. Some of the Strombolian eruptions caused glass to vibrate in buildings located 6.5 km NE. Block avalanches descended the N and NE flanks. Acid rain and small amounts of ejected pyroclastic material affected the NE, E, and SE flanks. Crater D produced only fumarolic activity.
Source: Observatorio Vulcanologico y Sismologico de Costa Rica-Universidad Nacional (OVSICORI-UNA)
Based on analyses of satellite imagery, the Darwin VAAC reported that on 8 September an ash plume from Batu Tara rose to an altitude of 2.4 km (8,000 ft) a.s.l. and drifted 55 km NW.
Source: Darwin Volcanic Ash Advisory Centre (VAAC)
Based on analyses of satellite imagery, the Darwin VAAC reported that during 8-11 and 14 September ash plumes from Dukono rose to an altitude of 2.4 km (8,000 ft) a.s.l. and drifted 35-95 km SW, W, and NW.
Source: Darwin Volcanic Ash Advisory Centre (VAAC)
KVERT reported that during 3-10 September seismic activity from Karymsky was above background levels and suggested that possible ash plumes rose to an altitude of 3.2 km (10,500 ft) a.s.l. Satellite imagery showed a thermal anomaly over the volcano during the week. The Aviation Color Code level remained at Orange.
Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
During 8-14 September HVO reported that activity at Kilauea continued from the summit caldera and the east rift zone. At the summit caldera, the level of the lava-pool surface in the deep pit within the floor of Halema'uma'u crater remained mostly stable; glow from the vent was also visible at night. A plume from the vent drifted SW and deposited ash, and occasionally Pele's hair and spatter, nearby. At Pu'u 'O'o crater, incandescence emanated from a lava flow on the SW floor on most nights. During an overflight on 9 September, geologists saw that the lava flow had ponded on the W side of the crater floor. At the east rift zone, lava that flowed through the TEB lava-tube system mainly fed the Puhi-o-Kalaikini ocean entry.
Source: US Geological Survey Hawaiian Volcano Observatory (HVO)
Based on information from JMA, the Tokyo VAAC reported that explosions from Sakura-jima on 8 and 10 September produced plumes that rose to altitudes of 1.5-1.8 km (6,000-8,000 ft) a.s.l. Some of the plumes drifted E and NE. On 9 September a pilot reported that an ash plume rose to an altitude of 3 km (10,000 ft) a.s.l.
The Washington VAAC reported that on 10 September a small plume and a thermal anomaly from Sangay were seen in satellite imagery. Based on information from Tegucigalpa MWO, pilot observations, and analyses of satellite imagery, the VAAC reported that on 13 September small plumes of gas with possible ash drifted SW. A thermal anomaly had also been detected for the previous few hours.
Source: Washington Volcanic Ash Advisory Center (VAAC)
KVERT reported that during 3-10 September seismic activity from Shiveluch was above background levels and suggested that possible ash plumes rose to an altitude of 6.5 km (21,300 ft) a.s.l. during 3-4 September. Gas-and-ash plumes were observed on 6 and 7 September; clouds prevented observations on the other days. Satellite imagery analysis showed a thermal anomaly on the volcano during the week. The Aviation Color Code level remained at Orange.
Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
MVO reported that several small-to-moderate sized pyroclastic flows from Soufrière Hills during 3-10 September removed parts of the cold dome carapace, resulting in the thermal camera displaying several hotter regions on the lava dome. The largest pyroclastic flow traveled 2.5 km down the Gages valley to the W on 9 September. The Hazard Level remained at 3.
Based on information from JMA, the Tokyo VAAC reported an explosion from Suwanose-jima on 11 September. Details of possible resulting plumes were not reported.
