The eruption that began at Manam on 24 October continued through at least 31 October. According to RVO, during 27-28 October there were occasional emissions of ash-laden brown clouds and projections of incandescent lava from Manam's Southern Crater. Fine ash from the eruptions traveled NW, and was deposited between the villages of Jogari and Baliau.
According to scientists from the Institute of Earth Sciences at the University of Iceland and the Icelandic Meteorological Office, an eruption began at the subglacial Grímsvötn volcano on 1 November around 2100. The eruption was preceded by both long-term and short-term precursors, and was triggered by the release of overburden pressure associated with a glacial outburst flood (jokulhlaup), originating from the Grímsvötn subglacial caldera lake.
According to CVO, during 28 October to 1 November, seismicity at St. Helens remained at a low level compared to early in the unrest. The seismicity during the report period was consistent with a continuing, slow rise of magma driving uplift of the crater floor and feeding a surface extrusion of lava.
Volcanic and seismic activity at Soufrière Hills continued to be at elevated levels during 22-29 October. The seismic network recorded one volcano-tectonic and 40 hybrid earthquakes. Like the previous week, the increased hybrid earthquake activity was thought to be related to heavy rainfall during the report period.
During 28-29 October, weak-to-moderate explosions occurred at Santa María's Santiaguito lava-dome complex, producing gas-and-ash plumes to ~800 m above the volcano. Some explosions were followed by collapses of the lava dome in the crater of Caliente dome. Pyroclastic flows traveled down the volcano's NE and SW flanks after some collapses.
According to NASA's Earth Observatory News website, the IKONOS satellite acquired an image of Montagu Island (Mount Belinda) on 1 October that showed a steaming vent, and dark basaltic tephra covering ice surfaces N of the lava that erupted down the volcano's N flank. A steam plume drifted N, and light colored clouds surrounded the S side of the crater.
During 28-31 October, surface lava was visible on the PKK lava flow on the Pulama pali fault scarp and all vents in the crater of Pu`u `O`o were incandescent. Seismicity was weak at Kilauea's summit and essentially no tremor was recorded. Tremor remained at moderate levels at Pu`u `O`o.
During 28-29 October, several weak explosions at Fuego sent plumes to a maximum height of 300 m above the volcano and volcanic bombs were sometimes thrown ~75 m above the volcano's crater. In addition, avalanches of incandescent volcanic material traveled ~600 m towards the ravine of the Ceniza River.
Wed, 27 Oct 2004, 06:00
During 27 October to 1 November, block-lava flows continued to travel down Colima's N, W, NW, and S flanks as they have since 30 September. Several explosions occurred daily. By 1 November, the block-lava flows on the N flank reached about 1,800 m long and about 200 m wide, and on the WNW flank block-lava reached about 600 m long and 200 m wide at its widest point.
Read allWed, 20 Oct 2004, 06:00
AVO lowered the Concern Color Codeat Veniaminof on 26 October from Yellow to Green. Seismicity, which had been associated with ash emissions that occurred during the summer of 2004, decreased to levels that indicated ash, ash-and-steam, or steam emissions were no longer occurring on a regular basis. Since early September, no ash emissions were seen on the web camera and no evidence of ash was visible on satellite imagery.
Read allWed, 20 Oct 2004, 06:00
During 21-26 October, the new lava dome inside the emerging dome of St Helens continued to grow, and seismicity remained at low levels compared to early in the unrest. Geological and thermal-imaging observations on 20 October confirmed that both the area of uplift, and the new lava extrusion increased in size noticeably since last seen on 14 October. In addition, the area of uplift and intense deformation continued to move southward and was nearing the crater wall.
Read allWed, 20 Oct 2004, 06:00
Based on information from JMA, a pilot report, and satellite imagery, the Darwin VAAC reported that an eruption began at Manam on 24 October around 1125, producing a plume to a maximum height of about 15 km (a height of ~6 km was reported in news articles). Preliminary reports from RVO stated that pyroclastic flows traveled down the valley SE of the volcano. The aviation color code was at Red, the highest value.
Read allWed, 20 Oct 2004, 06:00
Volcanic and seismic activity at Tungurahua during 21-26 October were at relatively low levels, characterized by a few long-period earthquakes, tremor, and small explosions. Emissions mainly consisted of steam, gas, and ash.
Read allWed, 20 Oct 2004, 06:00
Seismic activity at Soufrière Hills was at elevated levels during 15-22 October in comparison to previous weeks. The seismic network recorded four rockfall events and 49 hybrid earthquakes, and one volcano-tectonic earthquake. MVO scientists thought that increased hybrid earthquake activity was related to heavy rainfall during the week.
Read allWed, 20 Oct 2004, 06:00
On 26 October, AVO lowered the Concern Color Code at Shishaldin from Yellow to Green. Volcanic tremor at the volcano had remained at a relatively constant and low level for more than a month. No new satellite observations indicative of significant activity in the summit crater had been received by AVO, and there had been no recent reports of ash emissions or ash on the snow near the summit.
Read allWed, 20 Oct 2004, 06:00
During 15-22 October, seismicity at Shiveluch was above background levels, with shallow earthquakes occurring beneath the active lava dome. Based on interpretations of seismic data, ash-and-gas explosions possibly produced plumes to 6.5 km a.s.l. In addition, avalanches of hot material may have occurred during the week.
Read allWed, 20 Oct 2004, 06:00
During 21-22 October, weak-to-moderate explosions occurred at Santa María's Santiaguito lava-dome complex. Some explosions were followed by collapses of the SW edge of the lava dome in the crater of Caliente Dome. On 22 October two pyroclastic flows traveled down the volcano's flank.
Read allWed, 20 Oct 2004, 06:00
During 21-24 October, patches of incandescent lava were visible on the PKK lava flow on the Pulama pali fault scarp and all vents in the crater of Pu`u `O`o were incandescent. Seismicity was at low levels at Kilauea's summit and essentially no tremor was recorded there. Tremor was at moderate levels at Pu`u `O`o.
Read allWed, 20 Oct 2004, 06:00
During 21-22 October, several weak explosions at Fuego sent plumes to a maximum height of ~300 m above the volcano. In addition, avalanches of incandescent volcanic material traveled towards the ravines of Taniluyá and Ceniza on the volcano's flanks. The avalanches originated from two areas about 20 m below the S edge of Fuego's crater.
Read allWed, 20 Oct 2004, 06:00
During 22-26 October, block-lava flows continued to travel down Colima's N, NW, W, and S flanks as they have since 30 September. On the 26th, the block-lava flows on the N flank reached a length of ~1,800 m and a width of 200 m, and on the WNW flank the block-lava reached a length of ~600 m and a width of 200 m. On the 22nd, the volcano's gas output included 840 metric tons of sulfur dioxide.
Read allWed, 20 Oct 2004, 06:00
On 27 September, the first long-period seismic events since July 2004 were recorded at Anatahan. Only a few, small events were recorded. Beginning on 12 October, several periods of small, rather regularly spaced long-period events were recorded at intervals of 4 to 15 seconds.
Read allWed, 13 Oct 2004, 06:00
Low-level tremor continued at Veniaminof during 8-15 October, correlating with weak steaming of the intracaldera cone as observed on the web camera. No ash emissions were observed, although cloudy conditions over the caldera restricted viewing for much of the week. Veniaminof remained at Concern Color Code Yellow.
Read allWed, 13 Oct 2004, 06:00
During 13-18 October, seismicity was at low levels at St. Helens and growth of the new lava dome inside the volcano's crater continued. Gas-sensing flights on 13 October detected low levels of sulfur dioxide and hydrogen sulfide, but no carbon dioxide.
Read allWed, 13 Oct 2004, 06:00
According to DVGHM, volcanic tremor at Soputan began to increase to levels above normal on 18 October at 0930. In response, officials raised the Alert Level to Orange or 2 (on a scale of 1-4). Soputan erupted on 18 October at 1041, producing an E-drifting ash cloud to a height of ~600 m above the volcano's crater.
Read allWed, 13 Oct 2004, 06:00
Volcanic and seismic activity at Tungurahua during 13-18 October were at relatively low levels, characterized by a few long-period earthquakes, tremor, and small explosions. Emissions mainly consisted of steam and gas.
Read allWed, 13 Oct 2004, 06:00
Elevated levels of seismicity continued to be recorded at Spurr during 8-15 October. About 60 earthquakes were recorded within 30 km of the summit, with an average of about nine earthquakes per day. Spurr remained at Concern Color Code Yellow.
Read allWed, 13 Oct 2004, 06:00
Volcanic and seismic activity at Soufrière Hills remained at slightly elevated levels during 8-15 October, as they have since mid-September 2004. The seismic network recorded one rockfall and nine hybrid earthquakes. Sulfur-dioxide flux measurements were only possible on 2 days; 156 and 553 metric tons per day were recorded.
Read allWed, 13 Oct 2004, 06:00
Seismicity was above background levels at Shiveluch during 8-15 October, with weak shallow earthquakes occurring beneath the active lava dome. Two relatively strong shallow earthquakes, M 1.75 and 2.1, were recorded on 8 and 11 October, respectively. Spasmodic tremor was recorded during 7-12 October.
Read all
