On 28 November the Santa María seismic network recorded several explosions at Santiaguito lava dome. INSIVUMEH noted that many of the explosions were followed by block-and-ash avalanches, which traveled SW and S down Caliente cone. At least five collapses of megablocks from the S edge of the active crater generated short pyroclastic flows that descended to the base of Caliente cone.
Seismicity was above background levels at Kliuchevskoi during 21 to 28 November, with 80 shallow M 2-2.5 earthquakes and a large number of weak shallow events recorded. Strombolian activity was seen on the night of 21 November. Gas-and-steam plumes containing some ash rose to low levels above the crater on 23-24 November.
During 30 November to 2 December, incandescence was visible from lava in the upper flow field. Surface lava flows were not seen on the coastal flat or Pulama pali. At Kilauea, relatively strong shallow long-period seismicity at Halemaumau crater on 29 November decreased the following day.
During 21-28 November, possible ash-and-gas plumes rose to 1-1.5 km above Karymsky. In addition, seismicity was above background levels during the report period, with 160-210 shallow earthquakes occurring. Karymsky remained at Concern Color Orange.
During 28 November to 1 December, moderate-to-weak explosions at Fuego produced gas-and-ash plumes to heights of 700-900 m above the volcano. The explosions were accompanied by avalanches of volcanic material that traveled towards Teresa, Taniluyá, and Trinidad ravines. On the evening of 1 December, incandescence was seen in the ravines and in the active central crater.
During 26 November to 2 December, steam-and-ash plumes from Dukono were visible on satellite imagery. Plumes did not rise above 3 km and extended a maximum distance of ~65 km SE.
During 10-16 November, seismicity at Cotopaxi was at moderate levels, although it had increased in comparison to previous weeks. During the report period, seismicity was dominated by long-period earthquakes. Since late October volcano-tectonic earthquakes occurred beneath the zone of Pita and beneath the volcano's edifice.
On 1 and 2 December, ash clouds from Colima were visible on satellite imagery at a maximum height of ~7 km a.s.l.
Wed, 19 Nov 2003, 06:00
During 19-25 November, activity at Tungurahua remained high, with numerous moderate explosions producing plumes that were frequently visible on satellite imagery and rose up to 2 km above the crater. Ash was dispersed to the SSW and SW on 19 and 20 November and WNW and NW on 23 and 24 November, respectively. Throughout the week Strombolian activity was visible at night.
Read allWed, 19 Nov 2003, 06:00
An observer from The Wilderness Lodge reported that a 15-m-high island formed at Kavachi during an eruptive cycle 3 months prior to a visit on 16 November. By 16 November the summit had reduced to ~32 m below sea level. No evidence of volcanic activity was observed during the 3 previous months, which is the first time this has occurred in 4 years of observation.
Read allWed, 19 Nov 2003, 06:00
Small eruptions on 18 and 23 November at Santa María's Santiaguito lava dome produced localized tephra fall. Small avalanches from the SW portion of the dome occurred on 18 November. On 24 November at 0745, five explosions occurred at 1-minute intervals, producing a gas-and-ash plume that rose to 2 km above the crater and was dispersed up to 12 km SSW.
Read allWed, 19 Nov 2003, 06:00
Activity at Popocatépetl remained stable during the week with numerous gas-and-steam emissions. Based on information from the Mexico City MWO, the Washington VAAC reported that an ash plume was emitted on 22 November that rose to ~9.5 km a.s.l. and extended ~19 km NE.
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Strombolian activity was observed at Kliuchevskoi on 14-15 November. During 14-15 and 18 November, gas-and-ash plumes rose to ~2.5 km above the crater and extended more than 10 km W, E, and NE. During 15-20 November, seismic activity continued to be above background levels with 75 shallow M 1.9-2.5 earthquakes and many small, shallow earthquakes recorded.
Read allWed, 19 Nov 2003, 06:00
Minor surface lava flows were observed upslope of Kilauea's coastal plain the week of 19-25 November. Small amounts of inflation and deflation were recorded through the week with sharp deflation beginning at both Uwekahuna and Pu`u O`o early on the morning of 25 November. Moderate, shallow seismicity was recorded beneath the summit, and moderate-to-high seismicity occurred beneath Pu`u O`o.
Read allWed, 19 Nov 2003, 06:00
During 15-21 November, intermittent explosive eruptions at Karymsky produced gas-and-ash plumes that rose to 1.5-2 km above the crater. Karymsky remained at Concern Color Orange.
Read allWed, 19 Nov 2003, 06:00
Small explosive eruptions at Fuego produced gas-and-ash plumes up to 1.2 km above the crater. During the night of 18-19 November moderate-sized avalanches were observed in the upper Santa Teresa and Trinidad ravines. Night-time incandescence at the summit was common during the week.
Read allWed, 19 Nov 2003, 06:00
Satellite imagery showed ash plumes emitted from Dukono on 19 November at 1403, 20 November at 0713, and 21 November at 1428, extending ~185 km NE, ~170 km NE, and ~150 km ESE, respectively. A possible ash plume was observed on 22 November at 1349. All plumes were below ~3 km a.s.l.
Read allWed, 19 Nov 2003, 06:00
A subtle ash plume, visible in satellite imagery, was emitted from Colima on 18 November at 1900 and rose to ~5.5 km a.s.l.
Read allWed, 12 Nov 2003, 06:00
During 12-18 November, small-to-moderate eruptions of steam, gas, and some ash continued at Tungurahua. Plumes rose to ~2.5 km above the volcano, but there were no reports of ashfall in nearby towns. Strombolian activity was visible at the crater and avalanches of incandescent volcanic material rolled ~1 km down the volcano's flanks.
Read allWed, 12 Nov 2003, 06:00
During 7-14 November, volcanic activity at Soufrière Hills remained at low levels. The seismic network recorded three rockfall signals, one long-period earthquake, one long-period rockfall, and 36 hybrid earthquakes. Sulfur-dioxide emissions generally decreased from ~800 to ~200 tons per day during the report period.
Read allWed, 12 Nov 2003, 06:00
INSIVUMEH reported that as of 17 November, several weak-to-moderate eruptions took place from Santa María's Santiaguito lava dome. Plumes rose to ~700 m above the crater and drifted SW. According to the Washington VAAC, a pilot saw a plume above Santa María on 16 November.
Read allWed, 12 Nov 2003, 06:00
During 7-14 November, seismicity was above background levels at Kliuchevskoi, with the occurrence of 43 large shallow earthquakes (M 1.9-2.5), a large number of weak shallow earthquakes, and spasmodic tremor. Gas-and-steam plumes rose to ~2.5 km above the crater. Strombolian activity was visible at the volcano's central crater during the evening of 9-10 November.
Read allWed, 12 Nov 2003, 06:00
During 12-17 November, areas of surface lava were visible upslope of Kilauea's coastal flat. Seismicity at Kilauea's summit continued at moderate levels, with one or two small low-frequency earthquakes per minute occurring at shallow depths beneath the summit caldera. There were some larger earthquakes at depths of a few kilometers.
Read allWed, 12 Nov 2003, 06:00
During 7-14 November, seismicity was above background levels at Karymsky. The number of shallow earthquakes increased from 150 to 220 per day. Possible ash-and-gas explosions rose to 1-1.5 km above the volcano. Karymsky remained at Concern Color Code Orange.
Read allWed, 12 Nov 2003, 06:00
During 12-18 November, ash plumes continued to be emitted from Dukono. Plumes rose to ~3 km a.s.l. and extended a maximum distance of ~300 km to the NE.
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During 3-9 November, about nine earthquakes occurred per day at Cayambe, near the daily average since August 2003 and about twice the daily average of 4 per day before that. Seismicity also included small clusters of tectonic earthquakes with magnitudes less than 3. There were reports of a strong scent of sulfur in the sector of Picos Jarrína at an elevation of ~5,460 m.
Read allWed, 12 Nov 2003, 06:00
During 7-14 November, seismicity was above background levels at Alaid. Spasmodic volcanic tremor occurred and a large number of weak local earthquakes were recorded. Clouds obscured satellite images of the volcano. Alaid remained at Concern Color Code Yellow.
Read allWed, 5 Nov 2003, 06:00
Tungurahua maintained a generally low level of activity, with occasional plumes (often ash-poor) rising to less than 1 km above the summit. In contrast, a few ash-bearing emissions occurred. For example, on 5, 6, and 7 November there were ash falls of low intensity in the volcano's eastern sector.
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