Reports of increased volcanic activity at Barren Island and Narcondam volcanoes during the week of 2 January were found to be false. Professor Chandrasekharam from the Indian Institute of Technology reported that as of 4 January no unusual volcanic activity was occurring at these volcanic islands. Newspaper reports of active "mud volcanoes" in the Andaman Islands caused a great deal of concern and confusion.
On 29 December, the Tokyo VAAC reported an eruption at Suwanose-jima that produced an ash plume to ~1.2 km a.s.l. Eruptions were also reported on 1 and 4 January, but no plumes were visible on satellite imagery.
Lava-dome growth continued at St. Helens during 28 December to 4 January. Observations on 3-4 January indicated that the new dome, with the exception of the northern-most portion, was becoming heavily fractured and faulted.
Seismic unrest continued at Spurr during 26-31 December, with an average of 5-6 earthquakes recorded per day. A distinct increase in seismicity occurred on 26 December when 25 earthquakes were recorded. Spurr remained at Concern Color Code Yellow.
During 24-31 December, one long-period, six hybrid, and two volcano-tectonic earthquakes were recorded at Soufrière Hills. The sulfur-dioxide flux averaged 410 metric tons per day and ranged between 300 and 550 metric tons per day.
During 23-28 December, seismicity decreased slightly at Shiveluch but remained above background levels. Seismicity indicated that possible ash-and-gas explosions occurred on 26 and 27 December and plumes may have risen as high as ~4 km a.s.l. Observed explosions also occurred on 26 and 27 December that produced gas-and-ash explosions to ~2 km above the lava dome.
On 29 December the Darwin VAAC, based on information from RVO, reported that Manam was at Alert Level 2, a reduction from the previous Alert Level 3. During 1-4 January, Manam produced variable emissions.
During 3-4 January, surface lava flows were visible at Kilauea along the PKK lava flow on the Pulama pali fault scarp and on the coast. Summit seismicity remained low on both days with only a few long-period earthquakes recorded per day, and weak-to-absent background tremor. At Pu`u `O`o cone tremor remained at moderate levels, with periods of slight inflation and deflation recorded.
Wed, 29 Dec 2004, 06:00
On 28 December, an observed eruption at Karymsky produced a plume composed primarily of gas and steam, but with some ash, that rose to ~1 km above the crater. Thermal anomalies were also visible on satellite imagery on 27 and 28 December. On 30 December the Tokyo VAAC reported that a plume was present up to ~8 km a.s.l. and extending SW.
Read allWed, 29 Dec 2004, 06:00
According to the Washington VAAC, on 30 December an ash plume was visible at Colima on satellite imagery. The plume rose to ~7 km a.s.l. and extended as far as ~37 km E.
Read allWed, 22 Dec 2004, 06:00
During 22-27 December, activity at Tungurahua consisted of small-to-moderate explosions, several long-period earthquakes, and episodes of tremor. Emissions of steam, gas, and small amounts of ash rose to a maximum height of 1.5 km above the volcano on 22 December.
Read allWed, 22 Dec 2004, 06:00
Based on information from JMA, the Tokyo VAAC reported that eruptions at Suwanose-jima produced ash plumes to unknown heights on 22, 24, 25, and 27 December. The plumes were not visible on satellite imagery.
Read allWed, 22 Dec 2004, 06:00
During 22-28 December, growth of the new lava dome inside the crater of St. Helens continued, accompanied by low rates of seismicity, low emissions of steam and volcanic gases, and minor production of ash. Analysis of gas emissions sampled during the previous week revealed that no significant change had occurred.
Read allWed, 22 Dec 2004, 06:00
During 17-24 December, six hybrid earthquakes and one volcano-tectonic earthquake were recorded by the seismic network at Soufrière Hills. Sulfur-dioxide flux ranged 200-500 metric tons per day, with an average of 325 metric tons per day. An observation flight revealed the continued existence of an explosion-pit pond and no lava-dome growth.
Read allWed, 22 Dec 2004, 06:00
Seismicity was above background levels at Shiveluch during 19-22 December, with weak shallow earthquakes occurring at a depth of ~0.5 km beneath the active lava dome. Based on interpretations of seismic data, ash-and-gas explosions may have risen to 3.5 km a.s.l. on 20 December.
Read allWed, 22 Dec 2004, 06:00
On 22 December, explosions at Santa María's Santiaguito lava-dome complex produced ash plumes to 700-1,300 m above the dome. Small collapses occurred from lava-flow fronts on the SW side of Caliente Dome. According to the Washington VAAC, ash plumes were visible on satellite imagery on several days during 22-27 December.
Read allWed, 22 Dec 2004, 06:00
According to the Washington VAAC, on 28 December around 0715 satellite imagery showed a plume from Sangay that was most likely composed of steam with little ash. The plume was E of the volcano's summit at a height of ~6.4 km a.s.l. A hotspot was prominent on satellite imagery, but ash was more difficult to distinguish.
Read allWed, 22 Dec 2004, 06:00
During 19-26 December, seismic signals at Reventador revealed that lava emission that began in early November continued. Seismic signals also suggested that mudflows occurred on 17 and 19 December.
Read allWed, 22 Dec 2004, 06:00
Based on information from RVO, the Darwin VAAC reported that eruptions continued at Manam during 22-28 December. The Alert Level remained at 3.
Read allWed, 22 Dec 2004, 06:00
During 22-28 December, several areas of surface lava were visible at Kilauea along the PKK lava flow on the coastal flat, and along the Pulama pali fault scarp. Overall seismicity at the summit was low, but a few long-period earthquakes continued to occur. Tremor was essentially absent at the summit and moderate at Pu`u `O`o cone.
Read allWed, 22 Dec 2004, 06:00
On 22 December a narrow lava flow on Fuego's S flank reached a distance of ~200 m from the central crater. Many small block-lava avalanches traveled SW towards the Taniluyá River. The Washington VAAC reported that steam-and-ash emissions on 23 December rose to ~4.5 km a.s.l.
Read allWed, 15 Dec 2004, 06:00
During 15-20 December, activity at Tungurahua consisted of small-to-moderate explosions, several long-period earthquakes, and episodes of tremor. Emissions of steam, gas, and small amounts of ash rose to a maximum height of 2 km above the volcano.
Read allWed, 15 Dec 2004, 06:00
Based on information from RVO, the Darwin VAAC reported that the Alert Level at Manam was raised from 2 to 3 on 19 December. During 19-20 December, satellite imagery showed that ash plumes rose to at least 9 km a.s.l. and ash high as 15 km a.s.l. and drifted ~460 km WSW of Manam.
Read allWed, 15 Dec 2004, 06:00
Based on information from JMA, the Tokyo VAAC reported that an eruption at Suwanose-jima on 20 December produced a SE-drifting plume to ~1.8 km a.s.l. Also, on 21 December an eruption produced a SE-drifting ash plume to an unknown height.
Read allWed, 15 Dec 2004, 06:00
During 16-20 December, growth of the new lava dome inside the crater of St. Helens continued, accompanied by low rates of seismicity, low emissions of steam and volcanic gases, and minor production of ash. Observations on 16 December revealed that the lava dome had noticeably widened, the prominent fracture system along its top continued to widen, and ash was intermittently emitted from hot cracks.
Read allWed, 15 Dec 2004, 06:00
During 10-17 December, at Soufrière Hills six hybrid earthquakes and seven volcano-tectonic earthquakes were recorded by the seismic network. The sulfur-dioxide flux ranged 290-450 metric tons per day, averaging 360 tons per day. During the late afternoon of 15 December, heavy rain caused a mudflow in the Belham Valley.
Read allWed, 15 Dec 2004, 06:00
During 15-21 December, weak-to-moderate explosions occurred at Santa María's Santiaguito lava-dome complex, producing plumes to a maximum height of 1.3 km above the crater. Block-lava avalanches traveled down the SW flank of Caliente Dome.
Read allWed, 15 Dec 2004, 06:00
On 16 December, a block lava flow from Reventador extended more than 1.5 km from the 2002 crater through a breach in the S portion of the crater wall. The flow front was ~600 m below the central vent and extended to the ESE. Lava extrusion from a vent in the crater likely began in early November, accompanied by a dramatic increase in volcano-tectonic earthquakes.
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