Activity for the week of 21 November-27 November 2001
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
| 0.171°S, 78.598°W
| Elevation 4784 m
IG's seismic data showed that an approximately 20-minute-long phreatic explosion began at Guagua Pichincha on 26 November around noon. Cloudy conditions prohibited visual observations, but a cloud composed mainly of gas, with small amounts of ash, may have been produced. The volcanic cloud was not visible in satellite imagery; it is believed to have stayed around summit level. Continuous tremor was recorded through at least the rest of the day. The last explosion at Guagua Pichincha occurred on 25 May 2001.
Sources: Instituto Geofísico-Escuela Politécnica Nacional (IG), Washington Volcanic Ash Advisory Center (VAAC)
| 77.53°S, 167.17°E
| Elevation 3794 m
As of 23 November, frequent Strombolian eruptions (~1-10 per day) occurred from a persistent ~15-m-diameter summit lava lake at Erebus. In addition, infrequent small ash eruptions took place at a vent adjacent to the lava lake.
Source: Mount Erebus Volcano Observatory
| Eastern Kamchatka (Russia)
| 54.049°N, 159.443°E
| Elevation 1513 m
A noticeable decrease in seismicity at Karymsky during the end of the week of 16-23 November led KVERT to reduce the Concern Color Code from Orange to Yellow. Seismicity remained slightly above background levels after the decrease in earthquakes and signals of possible ash-and-gas explosions. On 19 November an airline pilot reported that the volcano's edifice looked black. On 22 November KVERT observed that the upper part of the edifice was without snow and had steam emanating from it.
Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
| Solomon Islands
| 8.991°S, 157.979°E
| Elevation -20 m
A visit to Kavachi on 25 November revealed sulfur, mud, and tiny pieces of volcanic rock upwelling from the submarine volcano. The pieces of volcanic rock covered the sea surface over an area more than 100 m across. No explosive eruptions were seen during a 6 hour observation period.
Source: The Wilderness Lodge
| Hawaiian Islands (USA)
| 19.421°N, 155.287°W
| Elevation 1222 m
Lava continued to flow into the ocean at the Kamoamoa and E Kupapa`u entries. HVO personnel confirmed that the Kupapa`u entry was inactive, as was reported the previous week. Surface lava flows were visible near the E Kupapa`u entry and at spots above, on, and below the Pulama pali scarp along the Kamoamoa lava tube system. Generally, volcanic tremor remained at low-to-moderate levels at Kilauea's summit and Pu`u `O`o. The level of tremor was relatively low at the summit, but the number of small earthquakes remained well above average. Tremor at Pu`u `O`o varied in amplitude. Tiltmeters along the volcano showed no significant deformation.
Source: US Geological Survey Hawaiian Volcano Observatory (HVO)
| Central Kamchatka (Russia)
| 56.056°N, 160.642°E
| Elevation 4754 m
A gradual decrease in seismicity under Kliuchevskoi during 16-23 November led KVERT to reduce the Concern Color Code from Yellow to Green. The tallest gas-and-steam plume of the reporting interval was produced on 19 November. The plume rose 700 m above the dome and extended SE for more than 10 km.
Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
| Luzon (Philippines)
| 13.257°N, 123.685°E
| Elevation 2462 m
News reports on 21 November stated that lahars were generated at Mayon after several days of heavy rainfall mixed with unconsolidated material on the volcano's slopes. According to the civil defense, flooding caused more than 4,800 families to be evacuated from their homes.
Source: Philippine Institute of Volcanology and Seismology (PHIVOLCS)
| 19.023°N, 98.622°W
| Elevation 5393 m
During the week, Popocatépetl emitted small clouds of steam, gas, and minor amounts of ash. In addition, episodes of harmonic tremor were recorded. During a flight over the volcano on 21 November observers noticed a new 130-m-diameter lava dome growing inside the internal crater. The growth of this lava dome corresponded with increased emissions and seismicity on 17 and 18 November.
Source: Centro Nacional de Prevencion de Desastres (CENAPRED)
| North Island (New Zealand)
| 39.28°S, 175.57°E
| Elevation 2797 m
On 21 November at 0218 a moderate-to-large volcanic earthquake was recorded at Ruapehu. The earthquake was followed by ~1 hour of moderate-to-strong volcanic tremor. IGNS did not believe an eruption accompanied the earthquake because no air waves were recorded and there were no reports of unusual activity. As of 23 November, seismicity continued to be higher than normal. Ruapehu remained at Alert Level 1 (on a scale of 0-5).
| Central Kamchatka (Russia)
| 56.653°N, 161.36°E
| Elevation 3283 m
During 16-23 November a lava dome continued to grow in Shiveluch's active crater, and several eruptions produced ash, steam, and gas clouds. The highest reported ash cloud rose to 1-2 km above the dome on 19 November. Thermal anomalies in the active dome area were visible on satellite imagery. About 60 earthquakes with magnitudes greater than or equal to 1.7 occurred and weak, shallow seismic signals (possible collapses and avalanches) were registered. KVERT reduced the Color Concern Code from Orange to Yellow.
Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
| 16.72°N, 62.18°W
| Elevation 915 m
The level of volcanic activity at Soufrière Hills increased during 16-23 November in comparison to the previous week. Morphological changes were observed at the volcano's summit; lava-dome growth shifted from the E to the W and the summit area was crowned by spines with an average elevation of 940 m a.s.l. Rockfall activity was relatively low, but intensified towards the end of the report week. Rockfalls were mainly concentrated on the W side of the active area, rather than the E as in previous weeks. Incandescent material was visible at night on the E and W sides of dome. A hybrid and long-period earthquake swarm began on 14 November, reaching a peak on 21 November before slightly declining.
Source: Montserrat Volcano Observatory (MVO)
News Feeds and Google Placemarks
The RSS (Really Simple Syndication) feed is identical to the Weekly Volcanic Activity Report minus some features including the header information (latitude and longitude and summit elevation), the Geologic Summary, and a link to the volcano's page from the Global Volcanism Program. Each volcano report includes a link from the volcano's name back to the more complete information in the Weekly Volcanic Activity Report on the Smithsonian website.
The CAP (Common Alerting Protocol) feeds are XML files specifically formatted for disaster management. They are similar in content to the RSS feed, but contain no active links.
A Google Earth network link for the Weekly Volcanic Activity Report can be loaded into the free Google Earth software, and in turn will load placemarks for volcanoes in the current weekly report. Placemark balloons include the volcano name, report date, report text, sources, and links back to the GVP volcano page for that volcano and to the complete Weekly Report for that week.
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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RSS and CAP Feeds
An RSS (Really Simple Syndication) feed for the Weekly Volcanic Activity Report first made available on 5 March 2008 can be utilized with the aid of various free downloadable readers. The report content of the news feed is identical to the Weekly Volcanic Activity Report minus some features including the header information (latitude and longitude and summit elevation), the Geologic Summary, and a link to the volcano's page from the Global Volcanism Program. Each volcano report includes a link from the volcano's name back to the more complete information in the Weekly Volcanic Activity Report on the Smithsonian website. On 12 March 2009, GeoRSS tags were added so that the latitude and longitude for each volcano could be included with the feed.
At the end of each individual report is a list of the sources used. We would like to emphasize that the World Organization of Volcano Observatories (WOVO) website (http://www.wovo.org/) lists the regional volcano observatories that have the most authoritative data for many of these events.
CAP (Common Alerting Protocol) feeds are XML files specifically formatted for disaster management.
Google Earth Placemarks
A Google Earth network link for the Weekly Volcanic Activity Report was first made available on 1 April 2009. This file can be loaded into the free Google Earth software, and in turn will load placemarks for volcanoes in the current weekly report. Placemark balloons include the volcano name, report date, report text, sources, and links back to the GVP volcano page for that volcano and to the complete Weekly Report for that week.