SI / USGS Weekly Volcanic Activity Report

Nyiragongo (DR Congo) - Report for 27 January-2 February 2010 - NEW

Wed, 03 Feb 2010 01:48:21 -0500

During 27 January-2 February, the MODIS sensor aboard the Earth Observing System (EOS) satellite continued to frequently detect thermal anomalies from Nyiragongo, likely from lava lake activity. Based on analyses of satellite imagery, the Toulouse VAAC reported that during 30-31 January a diffuse plume drifted 240 km W.

Sources: Toulouse Volcanic Ash Advisory Center (VAAC), Hawai'i Institute of Geophysics and Planetology (HIGP) Moderate Resolution imaging Spectroradiometer (MODIS) Thermal Alert System

Tungurahua (Ecuador) - Report for 27 January-2 February 2010 - NEW

Wed, 03 Feb 2010 01:48:21 -0500

The IG reported that during 26 January-2 February explosions from Tungurahua were detected by the seismic network. Inclement weather occasionally prevented observations of the volcano; ash plumes were seen rising to altitudes no higher than 8 km (26,200 ft) a.s.l. Ashfall was noted almost daily in areas to the SW, W, and NW. Roaring noises and sounds resembling "cannon shots" 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.

Source: Instituto Geof�sico-Escuela Polit�cnica Nacional (IG)

Gaua (Vanuatu) - Report for 27 January-2 February 2010

Wed, 03 Feb 2010 01:48:21 -0500

On 29 January, the Vanuatu Geohazards Observatory reported significant changes in Gaua's activity over the previous two weeks. They noted that since 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. The Wellington VAAC reported that on 27 January an ash cloud was seen on satellite imagery. Strong explosions were seen and heard from East Gaua on 29 January. According to the VAAC, the Vanuatu Geohazards Observatory reported that gas-and-ash plumes rose to altitudes of 3 km (10,000 ft) a.s.l. and drifted S and W that same day.

Sources: Vanuatu Geohazards Observatory, Wellington Volcanic Ash Advisory Center (VAAC)

Karymsky (Russia) - Report for 27 January-2 February 2010

Wed, 03 Feb 2010 01:48:21 -0500

KVERT reported that during 22-29 January seismic activity from Karymsky 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 Color Code remained at Orange.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Kilauea (United States) - Report for 27 January-2 February 2010

Wed, 03 Feb 2010 01:48:21 -0500

During 27 January-2 February, HVO reported an active lava surface about 200 m below a vent in the floor of Kilauea's Halema'uma'u crater. 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 occasionally fresh spatter, downwind. Measurements indicated that the sulfur dioxide emission rate at the summit remained elevated; 400 and 1,000 tonnes per day were measured on 28 January and 1 February, respectively. The 2003-2007 average rate was 140 tonnes per 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.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Kliuchevskoi (Russia) - Report for 27 January-2 February 2010

Wed, 03 Feb 2010 01:48:21 -0500

KVERT reported that during 22-29 January seismic activity from Kliuchevskoi 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 Color Code remained at Orange.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Nyamuragira (Dem Rep Congo) - Report for 27 January-2 February 2010

Wed, 03 Feb 2010 01:48:21 -0500

During 27 January-2 February, the MODIS sensor aboard the Earth Observing System (EOS) satellite frequently detected thermal anomalies from Nyamuragira. The Toulouse VAAC reported that a diffuse ash plume was seen on satellite imagery on 29 January.

Sources: Toulouse Volcanic Ash Advisory Center (VAAC), Hawai'i Institute of Geophysics and Planetology (HIGP) Moderate Resolution imaging Spectroradiometer (MODIS) Thermal Alert System

Popocat�petl (M�xico) - Report for 27 January-2 February 2010

Wed, 03 Feb 2010 01:48:21 -0500

CENAPRED reported that during 27-31 January and 1 February emissions of steam and gas from Popocat�petl contained minor amounts of ash.

Source: Centro Nacional de Prevencion de Desastres (CENAPRED)

Sakura-jima (Japan) - Report for 27 January-2 February 2010

Wed, 03 Feb 2010 01:48:21 -0500

Based on information from JMA, the Tokyo VAAC reported that during 27 January-2 February multiple explosions from Sakura-jima produced plumes that rose to altitudes of 1.8-2.4 km (6,000-8,000 ft) 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 altitudes of 1.2-3 km (4,000-10,000 ft) a.s.l.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)

Sangay (Ecuador) - Report for 27 January-2 February 2010

Wed, 03 Feb 2010 01:48:21 -0500

Based on pilot observations, the Washington VAAC reported that on 2 February an ash plume from Sangay rose to an altitude of 8.2 km (27,000 ft) a.s.l. Ash was not identified in satellite imagery, although weather clouds were present in the area.

Source: Washington Volcanic Ash Advisory Center (VAAC)

Shiveluch (Russia) - Report for 27 January-2 February 2010

Wed, 03 Feb 2010 01:48:21 -0500

KVERT reported that during 22-29 January seismic activity from Shiveluch was above background levels, possibly indicating ash plumes rising to an altitude of 4.6 km (15,100 ft) 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 Color Code remained at Orange. Based on information from KEMSD, the Tokyo VAAC reported that during 29-30 January eruptions produced plumes that rose to altitudes of 4.9-5.8 km (16,000-19,000 ft) a.s.l.

Sources: Kamchatkan Volcanic Eruption Response Team (KVERT), Tokyo Volcanic Ash Advisory Center (VAAC)

Soufri�re Hills (United Kingdom) - Report for 27 January-2 February 2010

Wed, 03 Feb 2010 01:48:21 -0500

MVO reported that during 22-29 January activity from the Soufri�re Hills lava dome 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.

Source: Montserrat Volcano Observatory (MVO)

Suwanose-jima (Japan) - Report for 27 January-2 February 2010

Wed, 03 Feb 2010 01:48:21 -0500

Based on information from JMA, the Tokyo VAAC reported explosions from Suwanose-jima during 27 January-2 February. On 27 January, plumes rose to altitudes of 1.2-1.5 km (4,000-5,000 ft) a.s.l. and drifted W. Plumes rose to an altitude of 1.8 km (6,000 ft) a.s.l. on 29 January.

Source: Tokyo Volcanic Ash Advisory Center (VAAC)