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SI/USGS Weekly Volcanic Activity Report 27 January-2 February 2010 4 February 2010

Posted by admin in activity reports, Africa, Caribbean, Congo (Dem. Rep.), Ecuador, eruptions, Gaua, Hawaii, Japan, Kamchatka, Karymsky, Kilauea, Kliuchevskoi, Mexico, Nyamuragira, Nyiragongo, Pacific, Popocatépetl, Russia, Sakura-jima, Sangay, Shiveluch, Soufrière Hills, Suwanose-jima, Tungurahua, United States, Vanuatu, Weekly Volcanic Activity Reports.
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Some of the volcanic activity headlines this week:

  • Nyiragongo: probable lava lake activity producing thermal anomalies
  • Tungurahua: roars, rumbles, explosions, lava fountains
  • Gaua: activity intensified, explosions, dark ash plumes, strombolian activity

SI/USGS Weekly Volcanic Activity Report 27 January-2 February 2010

Click on the map for a larger version (1280 x 898 pixels).

The Smithsonian Institution/United States Geological Survey Weekly Volcanic Activity Report for 27 January-2 February 2010 is available on the Global Volcanism Program website. The following is a summary and not a substitute for the full report.

New activity/unrest: Nyiragongo (Democratic Republic of Congo), Tungurahua (Ecuador).

Ongoing activity: Gaua (Vanuatu), Karymsky (Russia), Kilauea (Hawaii, USA), Kliuchevskoi (Russia), Nyamuragira (Democratic Republic of Congo), Popocatépetl (Mexico), Sakura-jima (Japan), Sangay (Ecuador), Shiveluch (Russia), Soufrière Hills (Montserrat), Suwanose-jima (Japan).

Note: a.s.l. = ‘above sea level’.

NEW ACTIVITY/UNREST

Nyiragongo (Democratic Republic of Congo). During 27 January-2 February thermal anomalies were frequently detected, probably from lava lake activity. Toulouse VAAC reported that during 30-31 January a diffuse plume drifted 240 km W.

Tungurahua (Ecuador). During 26 January-2 February explosions were detected by the seismic network. Observations were occasionally impeded by bad weather. Ash plumes were seen rising no higher than 8 km a.s.l. Ashfall was noted almost daily in areas to the SW, W and NW. Roaring noises and ‘cannonades’ were reported. During 26 and 28-30 January lava fountains were seen and sometimes ejected incandescent blocks that fell onto and rolled down the flanks. On 31 January, a lahar descended the Chontapamba drainage to the W.

ONGOING ACTIVITY

Gaua (Vanuatu). An increase in activity was observed from 16 January: more gas was emitted and multiple explosions produced denser and darker ash plumes. During 22-29 January, the water level in the river to the E that Lake Letas feeds rose 10 cm. Gas-and-ash plumes rose 3 km and drifted S and W. On 24 January nearby villagers reported seeing ejected material from Strombolian activity. Wellington VAAC reported that on 27 January an ash cloud was seen on satellite imagery. Strong explosions were seen and heard on 29 January. Gas-and-ash plumes reportedly rose to 3 km a.s.l. and drifted S and W that same day.

Karymsky (Russia). During 22-29 January seismic activity was above background levels and possibly indicated weak ash explosions. Analyses of satellite imagery revealed a thermal anomaly over the volcano during 21-25 and 27 January. The Level of Concern Colour Code remained at Orange.

Kilauea (Hawaii, USA). An active lava surface about 200 m below a vent in the floor of Halema’uma’u crater was observed during 27 January-2 February. The lava surface occasionally spattered, and both rose and drained through a hole in the cavity floor. A plume from the vent drifted N, NW and W, dropping small amounts of ash and occasional fresh spatter downwind. The sulphur dioxide emission rate at the summit remained elevated: 400 tonnes/day on 28 January and 1,000 tonnes/day on 1 February (2003-2007 average rate = 140 tonnes/day). Lava from beneath the Thanksgiving Eve Breakout (TEB) and rootless shield complex flowed over 3 km SE through a lava tube system before breaking out onto the surface. Thermal anomalies detected by satellite and visual observations revealed active lava flows on top of and on the pali; lava burned forest on the W side of the TEB flows. Incandescence was seen from a vent low on the S wall of Pu’u ‘O’o crater.

Kliuchevskoi (Russia). During 22-29 January seismic activity was above background levels and lava continued to flow down the NW flank. Strombolian activity periodically ejected material 200 m above the crater, and phreatic explosions occurred from the front of the lava flow. Satellite imagery revealed a large daily thermal anomaly at the volcano. Ashfall was reported in Klyuchi, about 30 km to the NE, on 22 January. The Level of Concern Colour Code remained at Orange.

Nyamuragira (Democratic Republic of Congo). During 27 January-2 February thermal anomalies were frequently detected. Toulouse VAAC reported that a diffuse ash plume was seen on satellite imagery on 29 January.

Popocatépetl (Mexico). During 27-31 January and 1 February emissions of steam and gas contained minor amounts of ash.

Sakura-jima (Japan). Tokyo VAAC reported that during 27 January-2 February multiple explosions produced plumes that rose to 1.8-2.4 km a.s.l. and drifted SE, E and NE. During 27-29 January and 1-2 February pilots reported that ash plumes sometimes drifted SE and S at 1.2-3 km a.s.l.

Sangay (Ecuador). Washington VAAC reported that on 2 February an ash plume rose to 8.2 km a.s.l. Ash was not identified in satellite imagery, although weather clouds were present in the area.

Shiveluch (Russia). During 22-29 January seismic activity was above background levels, possibly indicating ash plumes rising to 4.6 km a.s.l. Fumarolic activity was occasionally observed. Analyses of satellite imagery revealed a large daily thermal anomaly from the lava dome. The Level of Concern Colour Code remained at Orange. Tokyo VAAC reported that during 29-30 January eruptions produced plumes that rose to 4.9-5.8 km a.s.l.

Soufrière Hills (Montserrat). During 22-29 January activity was variable as the lava dome continued to grow. Cycles of vigorous ash venting, rockfalls and pyroclastic flows occurred every five to seven hours. Pyroclastic flows traveled down multiple valleys, including Whites Ghaut to the NE, and W down Gages into Spring Ghaut. The increasing number of pyroclastic flows that traveled E down the Tar River Valley, frequently reaching the sea, were attributed to new lava-dome growth in the SE part of the lava dome. Ash fell across most of Montserrat on 23 January. Vigorous steaming from hot pyroclastic flows emplaced in the Belham Valley on 8 January was caused by heavy rains on 25 January. Small steam explosions generated steam plumes that sometimes contained ash. The Hazard Level remained at 4.

Suwanose-jima (Japan). Tokyo VAAC reported explosions during 27 January-2 February. On 27 January, plumes rose to 1.2-1.5 km a.s.l. and drifted W. Plumes rose to 1.8 km a.s.l. on 29 January.

ACKNOWLEDGEMENTS AND DISCLAIMER

The foregoing is a summary of the Smithsonian Institution/United States Geological Survey Weekly Volcanic Activity Report covering 27 January-2 February 2010. 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.

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