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SI/USGS Weekly Volcanic Activity Report 9-15 December 2009 19 December 2009

Posted by admin in activity reports, Caribbean, Chaitén, Chile, Colombia, Concepción, Dukono, eruptions, Fuego, Galeras, Guatemala, Hawaii, Indonesia, Japan, Kamchatka, Karymsky, Kilauea, Kliuchevskoi, Manam, Mayon, Nevado del Huila, Nicaragua, Pacaya, Papua New Guinea, Philippines, Piton de la Fournaise, Rabaul, Russia, Sakura-jima, Shiveluch, Soufrière Hills, Suwanose-jima, United States, Weekly Volcanic Activity Reports.
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SI/USGS Weekly Volcanic Activity Report 9-15 December 2009

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The Smithsonian Institution/United States Geological Survey Weekly Volcanic Activity Report for 9-15 December 2009 is available on the Global Volcanism Program website. The following is a summary and not a substitute for the full report.

New activity/unrest: Concepción (Nicaragua), Galeras (Colombia), Mayon (Philippines), Piton de la Fournaise (Réunion), Soufrière Hills (Montserrat).

Ongoing activity: Chaitén (Chile), Dukono (Indonesia), Fuego (Guatemala), Karymsky (Russia), Kilauea (Hawaii, USA), Kliuchevskoi (Russia), Manam (Papua New Guinea), Nevado del Huila (Colombia), Pacaya (Guatemala), Rabaul (Papua New Guinea), Sakura-jima (Japan), Santa María (Guatemala), Shiveluch (Russia), Suwanose-jima (Japan).

Note: a.s.l. = ‘above sea level’.

NEW ACTIVITY/UNREST

Concepción (Nicaragua). On 11 December an explosion of ash and gas produced a plume that rose 150 m above the crater. Ashfall was reported in three nearby communities.

Galeras (Colombia). An overflight on 3 December revealed thermal anomalies in the main crater measuring 155 degrees Celsius. During 8-11 December, seismic activity decreased although some seismic signals resembled patterns seen prior to previous eruptions. Sulphur dioxide emissions were low. On 12 December seismicity increased, and during 12-15 December earthquakes of up to magnitude 2.2 were detected within 2 km of the summit and at depths of up to 3 km below the summit. The Alert Level was raised to II (Orange: ‘eruption probable within days or weeks’).

Mayon (Philippines). On 11 December an explosion was detected by the seismic network. On 14 December incandescence emanated from the lava dome in the summit crater and incandescent material traveled as far as 3 km down the S and SE flanks. At least five minor explosions were detected by the seismic network. Some local ashfall was reported. The Alert Level was raised to 3, prompting the order to evacuate about 50,000 people living within an 8-km radius from the base of the volcano.

Piton de la Fournaise (Réunion). On 14 December an eruption was preceded by a seismic crisis and summit deformation. Sub-parallel fissures along the rim of Dolomieu crater fed lava flows on the S slope. A third fissure that also produced lava flows opened on the E flank. The lava stopped flowing during the night after a gradual decrease. On 15 December, gas was emitted from the S and SE fractures and low-intensity tremor was detected.

Soufrière Hills (Montserrat). During 4-11 December activity from the lava dome continued at a high level and pyroclastic flow activity was concentrated on the N side. Pyroclastic flows traveled as far as 2 km NW into Tyers Ghaut and NE in abundance down Tuitt’s Ghaut, and sometimes Whites Bottom Ghaut, continuing onto Farrell’s plain. A few small pyroclastic flows also descended the Tar River valley to the E. On 10 December a large seismic signal was associated with a relatively large pyroclastic flow in Tyers Ghaut that traveled 3.5 km, stopping just beyond the W end of Lee’s village. The event prompted the National Disaster Preparedness and Response Advisory Committee (NDPRAC) to raise the Hazard Level to 4, restricting the hours residents can enter certain pre-designated hazard areas.

ONGOING ACTIVITY

Chaitén (Chile). On 12 December Buenos Aires VAAC reported that a steam-and-gas plume from the lava-dome complex drifted SE at 1.5-2.1 km a.s.l.

Dukono (Indonesia). During 9-11 December during 9-11 December ash plumes rose to 3 km a.s.l. and drifted 90-130 km E and SE.

Fuego (Guatemala). Explosions on 11, 14 and 15 December produced ash plumes that rose to 4.1-4.7 km a.s.l. and drifted 8-12 km W and SW. Incandescence from the main crater and rumbling noises were noted. Avalanches descended the S and W flanks. Washington VAAC reported that on 12 December a gas-and-ash plume drifted 20 km W. On 15 December ashfall was reported in areas to the SW.

Karymsky (Russia). Analyses of satellite imagery revealed a thermal anomaly during 3 and 6-7 December. Ash deposits extended 45 km SE on 6 December. A new lava flow was seen on the S flank on 8 December. Seismic data were seldom available due to technical problems. The Level of Concern Color Code remained at Orange.

Kilauea (Hawaii, USA). During 9-15 December lava flowed SE from beneath the Thanksgiving Eve Breakout (TEB) and rootless shield complex through a lava tube system, reaching the ocean at multiple locations between Waikupanaha and areas farther to the W. Towards the beginning of the reporting period thermal anomalies detected by satellite and visual observations revealed occasional active lava flows. Incandescence was seen almost daily from Pu’u ‘O’o crater. The vent in Halema’uma’u crater continued to produce an off-white plume that drifted predominantly to the SW, dropping small amounts of ash downwind. Incandescence originated from a few holes in the deep floor of the vent cavity. On 13 December, lava ponded on the floor, crusted over, and blocked the holes. Incandescence was again visible the next
night.

Kliuchevskoi (Russia). During 4-11 December seismic activity was above background levels and lava continued to flow down the ESE flank. Strombolian activity ejected tephra 200-300 m above the crater. During 5-9 December gas-and-steam plumes containing small amounts of ash rose to 6.3 km a.s.l. and drifted E. Satellite imagery revealed a large daily thermal anomaly at the volcano. The Level of Concern Color Code remained at Orange.

Manam (Papua New Guinea). On 12 December Darwin VAAC reported an eruption that produced a plume that rose to 3 km a.s.l. and drifted 75 km N.

Nevado del Huila (Colombia). On 10 December Washington VAAC reported that an ash plume rose to 7 km a.s.l. and drifted S. Ash was not identified in satellite imagery due to meteorological clouds in the area. During 9-15 December seismic signals indicated occasional gas-and-ash emissions. White and bluish gas plumes seen on the web camera rose 2 km. Overflights revealed that the lava dome continued to grow and emit gases.

Pacaya (Guatemala). White and blue fumarolic plumes from MacKenney cone rose up 100 m and drifted S on 11, 14 and 15 December. Multiple lava flows on the S flank traveled 25-350 m. Incandescence from one of the inter-crater cones was noted.

Rabaul (Papua New Guinea). Strong explosions followed by emissions of grey ash occurred from Tavurvur cone towards the beginning of the 4-10 December reporting period. Diffuse white vapor was emitted during quieter intervals. Ash plumes rose 1 km above the summit and drifted SE towards Tokua and the Tokua airport, causing suspension of some flights. Based on analyses of satellite imagery, the Darwin VAAC reported that on 14 December an ash plume rose to 2.1 km a.s.l. and drifted 35 km SE.

Sakura-jima (Japan). Tokyo VAAC reported that explosions during 9-15 December produced plumes that rose to 1.8-2.4 km a.s.l. and drifted NE, E, SE and S. On 14 December a pilot reported that an ash plume drifted S at 2.7 km a.s.l.

Santa María (Guatemala). On 11, 14 and 15 December explosions from the Santiaguito lava dome complex produced ash plumes that rose to 2.8-3.5 km a.s.l. and drifted W and SW. Avalanches occasionally descended the SE flank of the dome. On 15 December, explosions generated pyroclastic flows that descended the E and SW flanks.

Shiveluch (Russia). During 4-11 December seismic activity was above background levels, possibly indicating ash plumes rising to an altitude of 5.5 km a.s.l. Fumarolic activity was seen with a video camera. Analyses of satellite imagery revealed a large daily thermal anomaly from the lava dome and an ash plume drifting 85 km SE on 6 December. The Level of Concern Color Code remained at Orange. Tokyo VAAC reported that on 13 December an eruption produced a plume that rose to 5.8 km a.s.l.

Suwanose-jima (Japan). Tokyo VAAC reported eruptions on 14 and 15 December. Plumes rose to 1.2-1.5 km a.s.l. and drifted E.

ACKNOWLEDGEMENTS AND DISCLAIMER

The foregoing is a summary of the Smithsonian Institution/United States Geological Survey Weekly Volcanic Activity Report covering 9-15 November 2009. It is provided for information only, and is based on but not a substitute for the full report, which comes with its own criteria and disclaimers. The map base is derived from the Smithsonian Institution/USGS/US Naval Research Laboratory This Dynamic Planet website.

For all our coverage of the SI/USGS Weekly Volcanic Activity Reports: Weekly Volcanic Activity Reports « The Volcanism Blog.

The Volcanism Blog

Comments

1. Boris Behncke - 19 December 2009

Since early this morning (19 December 2009) we’re having a quite remarkable seismic swarm at Etna, with dozens of events having magnitudes between 2.5 and 3, and two main events with magnitudes of 4.2 at 05.36 GMT and 4.6 at 09.01 GMT. The earthquake hypocenters lie at depths between 15 and 20 km, which is quite deep for Etna, and are centered below the northwestern flank of the volcano, which commonly is one of its less seismically active sectors. So far there’s no indicator that these earthquakes are related to magma movement.
Seismic signals of two of the seismic stations on Etna can be looked up here:
http://www.ct.ingv.it/Etna2007/SegSismici.asp?Staz=ESVO_HHZ_IT&Pos=6
http://www.ct.ingv.it/Etna2007/SegSismici.asp?Staz=ESPC_HHZ_IT&Pos=6


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