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Smithsonian / USGS Weekly Volcanic Activity Report

You are currently viewing Archived reports for the week of 21 November-27 November 2001.

 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.

Name Location Activity
Guagua Pichincha Ecuador New

Erebus Antarctica Ongoing
Karymsky Eastern Kamchatka (Russia) Ongoing
Kavachi Solomon Islands Ongoing
Kilauea Hawaiian Islands (USA) Ongoing
Klyuchevskoy Central Kamchatka (Russia) Ongoing
Mayon Luzon (Philippines) Ongoing
Popocatepetl Mexico Ongoing
Ruapehu North Island (New Zealand) Ongoing
Sheveluch Central Kamchatka (Russia) Ongoing
Soufriere Hills Montserrat Ongoing

New Activity / Unrest

Volcano index photo  Guagua Pichincha  | Ecuador  | 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)

Ongoing Activity

Volcano index photo  Erebus  | Antarctica  | 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

Volcano index photo  Karymsky  | 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)

Volcano index photo  Kavachi  | 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

Volcano index photo  Kilauea  | 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)

Volcano index photo  Klyuchevskoy  | 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)

Volcano index photo  Mayon  | 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)

Volcano index photo  Popocatepetl  | Mexico  | 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)

Volcano index photo  Ruapehu  | 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).

Source: GeoNet

Volcano index photo  Sheveluch  | 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)

Volcano index photo  Soufriere Hills  | Montserrat  | 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)

Weekly Reports Archive

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Agung Fourpeaked Lewotolo Sakar
Ahyi Fuego Little Sitkin Salak
Aira Fujisan Llaima San Cristobal
Akan Fukutoku-Oka-no-Ba Loihi San Miguel
Alaid Galeras Lokon-Empung San Vicente
Alu-Dalafilla Galunggung Lopevi Sangay
Ambae Gamalama Machin Sangeang Api
Ambang Gamkonora Makian Santa Ana
Ambrym Gaua Makushin Santa Maria
Anatahan Gorely Maly Semyachik Sarigan
Antuco Great Sitkin Manam Sarychev Peak
Apoyeque Grimsvotn Manda Hararo Saunders
Arenal Guagua Pichincha Marapi Semeru
Asamayama Guallatiri Maroa Semisopochnoi
Askja Guntur Martin Seulawah Agam
Asosan Hachijojima Masaya Sheveluch
Augustine Hakoneyama Mauna Loa Shishaldin
Avachinsky Heard Mayon Simbo
Awu Hekla McDonald Islands Sinabung
Axial Seamount Hierro Melimoyu Sinarka
Azul, Cerro Hokkaido-Komagatake Merapi Siple
Azumayama Home Reef Metis Shoal Sirung
Bagana Hood Midagahara Slamet
Balbi Hudson, Cerro Misti, El Soputan
Bamus Huila, Nevado del Miyakejima Sorikmarapi
Banda Api Hunga Tonga-Hunga Ha'apai Momotombo Sotara
Bardarbunga Ibu Monowai Soufriere Hills
Barren Island Ijen Montagu Island Soufriere St. Vincent
Batur Iliamna Moyorodake [Medvezhia] South Sarigan Seamount
Bezymianny Iliwerung Mutnovsky Spurr
Bogoslof Inielika Myojinsho St. Helens
Brava Ioto Nabro Stromboli
Bristol Island Iya Negra, Sierra Sulu Range
Bulusan Izu-Torishima Negro, Cerro Sumbing
Calbuco Jackson Segment Nightingale Island Sundoro
Callaqui Kaba Nishinoshima Suretamatai
Cameroon Kadovar Nisyros Suwanosejima
Campi Flegrei del Mar di Sicilia Kambalny Novarupta Taal
Cayambe Kanaga NW Rota-1 Tair, Jebel at
Cereme Kanlaon Nyamuragira Takawangha
Chachadake [Tiatia] Karangetang Nyiragongo Talang
Chaiten Karkar Okataina Tambora
Chiginagak Karthala Okmok Tanaga
Chikurachki Karymsky Ontakesan Tandikat-Singgalang
Chiles-Cerro Negro Kasatochi Oraefajokull Tangkoko-Duasudara
Chillan, Nevados de Katla Osorno Tangkubanparahu
Chirinkotan Kavachi Pacaya Tara, Batu
Chirpoi Kelimutu Pagan Telica
Cleveland Kelut Palena Volcanic Group Tenerife
Colima Kerinci Paluweh Tengger Caldera
Colo Ketoi Panarea Three Sisters
Concepcion Kharimkotan Papandayan Tinakula
Copahue Kick 'em Jenny Parker Tofua
Cotopaxi Kikai Pavlof Tokachidake
Cuicocha Kilauea Peuet Sague Tolbachik
Cumbal Kirishimayama Pinatubo Toliman
Dabbahu Kizimen Planchon-Peteroa Tongariro
Dempo Klyuchevskoy Poas Tungurahua
Descabezado Grande Kolokol Group Popocatepetl Turrialba
Dieng Volcanic Complex Korovin Puyehue-Cordon Caulle Ubinas
Dukono Koryaksky Rabaul Ulawun
Ebeko Krakatau Ranakah Unknown Source
Ebulobo Krummel-Garbuna-Welcker Raoul Island Unnamed
Egon Kuchinoerabujima Rasshua Veniaminof
Ekarma Kurikomayama Raung Villarrica
Epi Kusatsu-Shiranesan Redoubt West Mata
Erebus Kverkfjoll Reventador White Island
Erta Ale Lamington Rincon de la Vieja Witori
Etna Lamongan Rinjani Wolf
Etorofu-Yakeyama [Grozny Group] Langila Ritter Island Yasur
Eyjafjallajokull Lanin Rotorua Zaozan
Fernandina Lascar Ruang Zavodovski
Fogo Lengai, Ol Doinyo Ruapehu Zhupanovsky
Fonualei Leroboleng Ruiz, Nevado del Zubair Group
Fournaise, Piton de la Lewotobi Sabancaya
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 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.

4. Many news agencies do not archive the articles they post on the Internet, and therefore the links to some sources may not be active. To obtain information about the cited articles that are no longer available on the Internet contact the source.

5. USGS Disclaimer Statement for this Website:

Information presented on this website is considered public information and may be distributed or copied. Use of appropriate byline/photo/image credit is requested. We strongly recommend that USGS data be acquired directly from a USGS server and not through other sources that may change the data in some way. While USGS makes every effort to provide accurate and complete information, various data such as names, telephone numbers, etc. may change prior to updating. USGS welcomes suggestions on how to improve our home page and correct errors. USGS provides no warranty, expressed or implied, as to the accuracy, reliability or completeness of furnished data.

Some of the documents on this server may contain live references (or pointers) to information created and maintained by other organizations. Please note that USGS does not control and cannot guarantee the relevance, timeliness, or accuracy of these outside materials.

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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.

 Acronyms and Abbreviations

a.s.l. - above sea level

AVO - Alaska Volcano Observatory

AVHRR - Advanced Very High Resolution Radiometer

CENAPRED - Centro Nacionale de Prevencion de Desastres (México)

CONRED - Coordinadora Nacional para la Reducción de Desastres

COSPEC - Correlation Spectrometer

CVGHM (formerly VSI) - Center of Volcanology and Geological Hazard Mitigation

CVO - Cascades Volcano Observatory (USGS)

GMS - Geostationary Meteorological Satellite

GOES - Geostationary Operational Environmental Satellite

GVO - Goma Volcano Observatory

GVP - Global Volcanism Program (Smithsonian Institution)

HVO - Hawaiian Volcano Observatory (USGS)

ICE - Instituto Costarricense de Electricidad (Costa Rica)

IG - Instituto Geofísico (Ecuador)

IGNS - Institute of Geological and Nuclear Sciences (New Zealand) - now GNS Science

INETER - Instituto Nicaragüense de Estudios Territoriales (Nicaragua)

INGEMMET - Instituto Geológical Minero y Metalúrgico (Peru)

INGEOMINAS - Instituto Colombiano de Geología y Minería (Colombia)

INGV-CT - Istituto Nazionale di Geofisica e Vulcanologia - Sezione di Catania (Italy)

INSIVUMEH - Instituto Nacional de Sismologia, Vulcanologia, Meteorologia e Hidrologia (Guatemala)

IRD - Institut de Recherche pour le Développement (France)

JMA - Japanese Meteorological Agency

KEMSD - Kamchatkan Experimental and Methodical Seismilogical Department

KVERT - Kamchatkan Volcanic Eruption Response Team

M - magnitude

METEOSAT - Meteorological Satellite

MEVO - Mount Erebus Volcano Observatory

MODIS - Moderate Resolution Imaging Spectroradiometer

MVO - Montserrat Volcano Observatory

MWO - Meteorological Watch Office

NEIC - National Earthquake Information Center

NIED - National Research Institute for Earth Science and Disaster Prevention (Japan)

NOAA - National Oceanic and Atmospheric Administration

NOTAM - Notice to Airmen

OVDAS - Observatorio Volcanologico de los Andes del Sur (Chile)

OFDA - Office of US Foreign Disaster Assistance

ONEMI - Oficina Nacional de Emergencia - Ministerio del Interior (Chile)

OVPDLF - Observatoire Volcanologique du Piton de la Fournaise (France)

OVSICORI-UNA - Observatorio Vulcanologico y Sismologico de Costa Rica, Universidad Nacional (Costa Rica)

PHIVOLCS - Philippine Institute of Volcanology and Seismology (Philippines)

RSAM - Real-time Seismic Amplitude Measurement

RVO - Rabaul Volcano Observatory

SERNAGEOMIN - Servicio Nacional de Geologia y Mineria (Chile)

SIGMET - Significant Meteorological Information

SNET - Servicio Nacional de Estudios Territoriales (El Salvador)

SVERT - Sakhalin Volcanic Eruption Response Team (Russia)

USAID - US Agency for International Development

USGS - United States Geological Survey

UTC - Coordinated Universal Time

VAAC - Volcanic Ash Advisory Center

VAFTAD - Volcanic Ash Forecast Transport And Dispersion

VDAP - Volcano Disaster Assistance Program (USGS)

VHP - Volcano Hazards Program (USGS)

VRC - Volcano Research Center (Japan)