Activity for the week of 19 January-25 January 2005
The Weekly Volcanic Activity Report is a cooperative project between the Smithsonian's Global Volcanism Program and the US Geological Survey's Volcano Hazards Program. Updated by 2300 UTC every Wednesday, notices of volcanic activity posted on these pages are preliminary and subject to change as events are studied in more detail. This is not a comprehensive list of all of Earth's volcanoes erupting during the week, but rather a summary of activity at volcanoes that meet criteria discussed in detail in the "Criteria and Disclaimers" section. Carefully reviewed, detailed reports on various volcanoes are published monthly in the Bulletin of the Global Volcanism Network.
New Activity / Unrest
| 10.412°N, 123.132°E
| Elevation 2435 m
A brief ash emission began at Canlaon around 0930 on 21 January. The cloud produced from the emission rose to an approximate height of 500 m above the active crater and drifted WNW and SW. No coincident volcanic earthquakes were recorded. There were fine ash deposits in the city of Cabagnaan, ~5.5 km SW of the crater. PHIVOLCS advised the public to avoid entering the 4-km-radius Permanent Danger Zone around the volcano.
Source: Philippine Institute of Volcanology and Seismology (PHIVOLCS)
| Mariana Islands (USA)
| 16.35°N, 145.67°E
| Elevation 790 m
The third historical eruption of Anatahan began on 5 January, with explosions occasionally occurring through about 19 January. Near mid-day on 20 January seismicity at the volcano dropped abruptly to near background levels, indicating that explosions had ceased. Degassing may have continued. The apparent cessation of Strombolian activity lasted until late 22 January, when explosions suddenly resumed. The eruption peaked at about 0700 on 23 January. Pilots reported ash to heights of 3-4.5 km. After the peak in activity the explosions decreased somewhat, but were still frequent and strong as of 24 January.
The government of the Commonwealth of the Mariana Islands (CNMI), placed Anatahan Island off limits until further notice and concluded that, although the volcano is not currently dangerous to most aircraft within the CNMI airspace, conditions may change rapidly, and aircraft should pass upwind of Anatahan or beyond 30 km downwind from the island and exercise due caution within 30 km of Anatahan.
Source: Emergency Management Office of the Commonwealth of the Mariana Islands and United States Geological Survey Volcano Hazards Program
| 19.514°N, 103.62°W
| Elevation 3850 m
During 19-24 January, several explosions occurred daily at Colima. Ash plumes produced from these eruptions drifted predominately SE.
Source: Centro Universitario de Estudios e Investigaciones de Vulcanologia - Universidad de Colima
| 14.473°N, 90.88°W
| Elevation 3763 m
During 24-25 January, several weak-to-moderate explosions at Fuego produced ash plumes to a maximum height of 1.5 km above the volcano. The eruptions were accompanied by avalanches of incandescent volcanic blocks towards several ravines.
Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)
| Hawaiian Islands (USA)
| 19.421°N, 155.287°W
| Elevation 1222 m
During 19-25 January, surface lava from Kilauea was visible along the arms of the PKK lava flow traveling down the Pulama pali fault scarp, over Paliuli, and onto the coastal flat. Lava did not enter the sea. Seismicity at Kilauea's summit was relatively low during the report period, except during the morning of 25 January when quick inflation was accompanied by long-period earthquakes. Seismicity abruptly returned to background levels when the inflation ended.
Source: US Geological Survey Hawaiian Volcano Observatory (HVO)
| Central Kamchatka (Russia)
| 56.056°N, 160.642°E
| Elevation 4754 m
During 14-21 January, seismicity was above background levels at Kliuchevskoi and the total number of shallow earthquakes continued to increase. Gas-and-steam plumes rose to ~800 m above the lava dome. Incandescence was visible in the volcano's crater during several nights. Kliuchevskoi remained at Concern Color Code Orange.
Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
| Papua New Guinea
| 4.08°S, 145.037°E
| Elevation 1807 m
RVO reported that during 18-20 January there was a reduction in volcanic activity at Manam, but tremor continued. Steam plumes were emitted from Southern Crater and Main Crater. Small amounts of ash fell in the town of Waris on 20 January. It was not known which crater was the source of the ash. Overall, seismicity was at moderate-to-high levels. Manam remained at Alert Level 2.
Source: Rabaul Volcano Observatory (RVO)
| 14.382°N, 90.601°W
| Elevation 2569 m
During 24-25 January, lava flows from Pacaya traveled as far as 150 m down the volcano's SW flank.
Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)
| 19.023°N, 98.622°W
| Elevation 5393 m
According to the Washington VAAC, an explosion at Popocatépetl on 22 January produced a NE-drifting ash plume. CENAPRED reported that aerial photographs taken on 14 January showed subsidence in the inner crater of Popocatépetl and no external lava dome at the bottom of the crater. Popocatépetl remained at Alert Level Yellow- Phase 1, with access restricted within a 12-km radius around the crater.
Sources: Centro Nacional de Prevencion de Desastres (CENAPRED), Washington Volcanic Ash Advisory Center (VAAC)
| New Britain (Papua New Guinea)
| 4.271°S, 152.203°E
| Elevation 688 m
Based on information from RVO, the Darwin VAAC reported that ash emissions commenced at Rabaul on 25 January. Ash rose to ~500 m above the summit and drifted E.
Source: Darwin Volcanic Ash Advisory Centre (VAAC)
| 16.72°N, 62.18°W
| Elevation 915 m
During 14-21 January, at Soufrière Hills two hybrid earthquakes and two rockfalls were recorded by the seismic network. Sulfur-dioxide flux rates of 300 and 380 metric tons per day were recorded on 15 and 16 January, respectively. No significant change in the morphology of the volcanic edifice was seen during an observational flight on 19 January.
Source: Montserrat Volcano Observatory (MVO)
| United States
| 46.2°N, 122.18°W
| Elevation 2549 m
During 19-25 January, 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. On 19 January, crews investigated the effects of an eruption that occurred on 16 January around 0300. During a 17-minute period, there were explosive emissions of ash and volcanic blocks from the vent area at the N end of the growing lava dome. A shower of ballistic fragments pockmarked a snow-covered area up to several hundred meters NE of the lava dome with craters up to 1 m in diameter. Ash fell thickly in E and W parts of the crater and drifted eastward over the rim depositing a thin layer of gray ash on the E flank outward for at least 3 kilometers. The scale and impact of the explosion was similar to that of 1 October 2004.
Analysis of a digital-elevation model made from photographs taken on 3 January provided new information about the size of the lava dome. Since last measured on 11 December 2004, the lava dome had maintained its 475-meter length, which was constrained by the old lava dome and crater wall, but widened from 310 to 410 m. Its highest point was 7 m higher. The entire lava dome increased in volume from 30 to 34 million cubic meters, an average rate of about 2 cubic meters per second. Based on these results CVO suggested that the rate of lava extrusion had decreased from autumn 2004 rates. St Helens remained at Volcano Advisory (Alert Level 2); aviation color code Orange.
Source: US Geological Survey Cascades Volcano Observatory (CVO)
| 1.467°S, 78.442°W
| Elevation 5023 m
During 19-24 January, there were several emissions from Tungurahua of steam, gas, and ash. The plumes that were produced rose to a maximum height of ~1 km above the volcano and drifted in multiple directions. During the report period, small amounts of ash fell in the sectors of Agoyán, San Francisco, Runtón, Pondoa, and Baños. Seismicity was at relatively low levels.
Sources: Instituto Geofísico-Escuela Politécnica Nacional (IG), Washington Volcanic Ash Advisory Center (VAAC)
| United States
| 56.17°N, 159.38°W
| Elevation 2507 m
During 14-21 January, seismic data, web camera views, and satellite images indicated that low-level ash emissions continued at Veniaminof. Seismicity was similar to levels observed during the previous week, consisting of low-amplitude volcanic tremor with occasional larger bursts. During clear weather, satellite imagery showed anomalous heat at the summit cone, consistent with hot blocks and ash being ejected from the active vent. In addition, the web camera showed intermittent ash plumes reaching as high as 3 km a.s.l. Occasional stronger bursts of seismic tremor during 20-21 January may have indicated plumes to higher levels, but not above 4 km. Veniaminof remained at Concern Color Code Orange.
Source: US Geological Survey Alaska Volcano Observatory (AVO)
Criteria & Disclaimers
The Weekly Volcanic Activity Report does not necessarily include all volcanic activity that occurred on Earth during the week. More than a dozen volcanoes globally have displayed more-or-less continuous eruptive activity for decades or longer, and such routine activity is typically not reported here. Moreover, Earth's sea-floor volcanism is seldom reported even though in theory it represents the single most prolific source of erupted material. The Weekly Volcanic Activity Report summarizes volcanic activity that meets one or more of the following criteria:
- A volcano observatory raises or lowers the alert level at the volcano.
- A volcanic ash advisory has been released by a volcanic ash advisory center (VAAC) stating that an ash cloud has been produced from the volcano.
- A verifiable news report of new activity or a change in activity at the volcano has been issued.
- Observers have reported a significant change in volcanic activity. Such activity can include, but is not restricted to, pyroclastic flows, lahars, lava flows, dome collapse, or increased unrest.
Volcanoes are included in the "New Activity/Unrest" section of the Weekly Volcanic Activity Report if the activity occurs after at least 3 months of quiescence. Once a volcano is included in the "New Activity/Unrest" section, updates will remain in that section unless the activity continues for more than 1 month without escalating, after which time updates will be listed in the "Continuing Activity" section. Volcanoes are also included in the "New Activity/Unrest" section if the volcano is undergoing a period of relatively high unrest, or increasing unrest. This is commonly equal to Alert Level Orange on a scale of Green, Yellow, Orange, Red, where Red is the highest alert. Or alert level 3 on a scale of 1-4 or 1-5.
It is important to note that volcanic activity meeting one or more of these criteria may occur during the week, but may not be included in the Weekly Volcanic Activity Report because we did not receive a report.
1. The Weekly Volcanic Activity Report is intended to provide timely information about global volcanism on a weekly basis. Consequently, the report is generated rapidly by summarizing volcanic reports from various sources, with little time for fact checking. The accuracy of the Weekly Volcanic Activity Report is dependent upon the quality of the volcanic activity reports we receive. Reports published in the Bulletin of the Global Volcanism Network are monthly, and more carefully reviewed, although all of the volcanoes discussed in the Weekly Volcanic Activity Report are not necessarily reported in the Bulletin. Because of our emphasis on rapid reporting on the web we have avoided diacritical marks. Reports are updated on the Weekly Volcanic Activity Report web page as they are received, therefore information may be included regarding events that occurred before the current report period.
2. Rapidly developing events lead to coverage that is often fragmentary. Volcanoes, their eruptions, and their plumes and associated atmospheric effects are complex phenomena that may require months to years of data analysis in order to create a comprehensive summary and interpretation of events.
3. Preliminary accounts sometimes contain exaggerations and "false alarms," and accordingly, this report may include some events ultimately found to be erroneous or misleading.
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