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Smithsonian / USGS Weekly Volcanic Activity Report

You are currently viewing Archived reports for the week of 18 April-24 April 2001.


















 Activity for the week of 18 April-24 April 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
Marapi Indonesia New
Masaya Nicaragua New

Batur Bali (Indonesia) Ongoing
Cleveland Chuginadak Island (USA) Ongoing
Etna Sicily (Italy) Ongoing
Ijen Eastern Java (Indonesia) Ongoing
Kilauea Hawaiian Islands (USA) Ongoing
Mayon Luzon (Philippines) Ongoing
Merapi Central Java (Indonesia) Ongoing
Popocatepetl Mexico Ongoing
Semeru Eastern Java (Indonesia) Ongoing
Sheveluch Central Kamchatka (Russia) Ongoing
Soufriere Hills Montserrat Ongoing
Tungurahua Ecuador Ongoing


New Activity / Unrest


Volcano index photo  Marapi  | Indonesia  | 0.38°S, 100.474°E  | Elevation 2885 m

Based on information from VSI, the Darwin VAAC reported that after increased volcanic activity occurred over the preceding two weeks VSI raised the Alert Level at Marapi from 1 to 2. The increased activity included an eruption on 16 April that sent an ash cloud up to 2 km above the summit. In addition, an eruption on about 23 April produced an ash cloud that rose up to ~6 km a.s.l. and drifted to the E.

Sources: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM), Darwin Volcanic Ash Advisory Centre (VAAC)



Volcano index photo  Masaya  | Nicaragua  | 11.984°N, 86.161°W  | Elevation 635 m

At 1426 on 23 April a small explosion at Masaya's Santiago crater lasted for ~2 minutes and occurred in three phases. During the first phase volcanic gas under high pressure was explosively released and created a new vent in the bottom of Santiago crater. The eruption sent rock fragments up to 60 cm in diameter as far as 500 m from the crater. Several vehicles parked at a visitors platform near the crater were damaged by the ejecta and one person suffered minor injuries. During the second and third phases a mixture of hot volcanic gas, pieces of lava, and ash ignited dry vegetation near the crater. INETER personnel who monitored the seismic activity before the eruption and scientists from Cambridge University who were working in the crater one hour before the eruption did not notice any unusual activity at the volcano. INETER personnel monitored the volcano after the eruption and found that several small explosions, gas outbreaks, and minor collapses of the crater wall occurred. They warned that further explosions may occur that could affect areas near the crater (within ~500 m).

Sources: Associated Press, Instituto Nicaragüense de Estudios Territoriales (INETER)



Ongoing Activity


Volcano index photo  Batur  | Bali (Indonesia)  | 8.242°S, 115.375°E  | Elevation 1717 m

VSI reported that there were no major changes visible at Batur during 9-15 April. Thin steam plumes continued to rise above the volcano's crater. Seismographs recorded no shallow volcanic earthquakes, two deep volcanic earthquakes, two small explosion earthquakes, and 17 tectonic earthquakes. The volcano remained at Alert Level 2 (on a scale of 1-4).

Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)



Volcano index photo  Cleveland  | Chuginadak Island (USA)  | 52.825°N, 169.944°W  | Elevation 1730 m

Volcanic unrest continued at Cleveland through 20 April. A thermal anomaly was persistently detected in satellite imagery on days when the weather was clear to partly cloudy. Low-level pulses of volcanic tremor were detected several times during the week by an AVO seismic network 230 km to the E of the volcano. AVO received no reports of significant volcanic activity from either pilots, residents, or satellite remote sensors.

Source: US Geological Survey Alaska Volcano Observatory (AVO)



Volcano index photo  Etna  | Sicily (Italy)  | 37.748°N, 14.999°E  | Elevation 3295 m

Sistema Poseidon reported that during 9-15 April volcanic activity at Etna was similar to the previous week. Strombolian activity continued at Bocca Nuova crater, although by the end of the report period activity decreased in comparison to previous weeks. Lava also continued to flow down the NE flank of Southeast Crater, and degassing continued at Voragine and Northeast craters. The Australian Broadcasting Corporation reported that on about 22 April thirty small earthquakes occurred near Etna, but did not cause any injuries or property damage.

Sources: ABC News - Australian Broadcasting Corporation, Sezione di Catania - Osservatorio Etneo (INGV)



Volcano index photo  Ijen  | Eastern Java (Indonesia)  | 8.058°S, 114.242°E  | Elevation 2769 m

Volcanic activity at Ijen during 9-15 April was higher than normal, with a relatively large number (nine) of shallow volcanic earthquakes. Seismographs also recorded ten small explosion events. The volcano remained at Alert Level 2 (on a scale of 1-4).

Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)



Volcano index photo  Kilauea  | Hawaiian Islands (USA)  | 19.421°N, 155.287°W  | Elevation 1222 m

Surface lava flows were visible above the Pulama Pali and traveling down it without reaching the coast. The lava flows were predominately pahoehoe with minor `a`a. Generally, volcanic tremor near Pu`u `O`o cone and in Kilauea's caldera was at low levels, although a swarm of long-period earthquakes occurred beneath the caldera from 18 to at least 24 April. Tiltmeters in the summit area and along the east rift zone indicated no significant deformation.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)



Volcano index photo  Mayon  | Luzon (Philippines)  | 13.257°N, 123.685°E  | Elevation 2462 m

PHIVOLCS reported that during the week ending on 15 April there had been a total of 60 low-frequency earthquakes and 13 high-frequency short-duration harmonic tremors. The SO2 flux during the same period averaged 3,400 metric tons/day, which is still significantly above the baseline value of 500 tons/day. Deformation monitoring showed that the volcano was inflated, but the present trend revealed insignificant change. Moderate steaming was typical. Faint incandescence was observed at the crater using a telescope for approximately an hour on both 16 and 17 April; the incandescence was graded as level 1 intensity. Alert Level 3 remained in effect, prohibiting entry within the 6-km-radius permanent danger zone.

Source: Philippine Institute of Volcanology and Seismology (PHIVOLCS)



Volcano index photo  Merapi  | Central Java (Indonesia)  | 7.54°S, 110.446°E  | Elevation 2910 m

VSI reported that during 9-15 April lava avalanches continued to fill the upstream areas of the Sat, Senowo, Lamat, and Bebeng rivers, with a maximum runout distance of 2 km in the Sat River. In addition, eleven pyroclastic flows entered the Sat and Lamat rivers, reaching as far as 3 km. Avalanche earthquakes continued to dominate the seismicity, but their amplitude and frequency decreased in comparison to the previous week. An observer reported that on 13 April a small amount of ash fell around the Babadan Post Observatory ~7 km W of the volcano. Merapi remained at Alert Level 2 (on a scale of 1-4).

Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)



Volcano index photo  Popocatepetl  | Mexico  | 19.023°N, 98.622°W  | Elevation 5393 m

Small-to-moderate exhalations continued at Popocatépetl. On 17 April a small lahar traveled down the Achupashal Gorge. The volcano remained at Alert Level Yellow Phase III, with a restricted 12-km-radius area.

Sources: Associated Press, Centro Nacional de Prevencion de Desastres (CENAPRED), Washington Volcanic Ash Advisory Center (VAAC)



Volcano index photo  Semeru  | Eastern Java (Indonesia)  | 8.108°S, 112.922°E  | Elevation 3657 m

VSI reported that during 9-15 April activity at Semeru was higher than normal. Minor explosions that rose 300 m above the volcano were observed during clear weather. Seismographs recorded an increase in seismicity in comparison to the previous week, with 339 explosion events, 51 avalanche events, and three tectonic earthquakes. Semeru remained at Alert Level 2 (on a scale of 1-4).

Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)



Volcano index photo  Sheveluch  | Central Kamchatka (Russia)  | 56.653°N, 161.36°E  | Elevation 3283 m

During 13-20 April seismic activity was above background levels at Shiveluch before increasing sharply on 22 April. Heavy clouds prevented visual observations of the volcano, but seismic data suggested that no ash explosions occurred. Due to the high seismic activity KVERT raised the Concern Color Code from Yellow to Orange.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)



Volcano index photo  Soufriere Hills  | Montserrat  | 16.72°N, 62.18°W  | Elevation 915 m

MVO reported that during 13-20 April volcanic activity at Soufrière Hills remained low, with few rockfalls and little seismicity. A swarm of hybrid earthquakes occurred primarily during 0419 to 0741 on 20 April. A very small amount of growth occurred on the S side of the lava dome, which was accompanied by occasional ash venting. Sulfur dioxide flux also remained low.

Source: Montserrat Volcano Observatory (MVO)



Volcano index photo  Tungurahua  | Ecuador  | 1.467°S, 78.442°W  | Elevation 5023 m

IG stated that during the night of 20 April incandescence was visible in the interior of the dome and the next day a steam column rose a short distance above the summit. IG warned that residents near the volcano should be alert to the possibility of mud flows forming during periods of heavy rain. Since 5 September 2000, the Alert Level has been at Yellow in the town of Baños and at Orange for the rest of the population in the high-risk zone.

Sources: Instituto Geofísico-Escuela Politécnica Nacional (IG), Washington Volcanic Ash Advisory Center (VAAC)



Weekly Reports Archive

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Bamus Hunga Tonga-Hunga Ha'apai Monowai Soufriere Hills
Banda Api Ibu Montagu Island Soufriere St. Vincent
Bardarbunga Ijen Moyorodake [Medvezhia] South Sarigan Seamount
Barren Island Iliamna Mutnovsky Spurr
Batur Iliwerung Myojinsho St. Helens
Bezymianny Inielika Nabro Stromboli
Bogoslof Ioto Negra, Sierra Sulu Range
Brava Iya Negro, Cerro Sumbing
Bristol Island Izu-Torishima Nightingale Island Sundoro
Bulusan Jackson Segment Nishinoshima Suretamatai
Calbuco Kaba Nisyros Suwanosejima
Callaqui Kadovar Novarupta Taal
Cameroon Kambalny NW Rota-1 Tair, Jebel at
Campi Flegrei del Mar di Sicilia Kanaga Nyamuragira Takawangha
Cayambe Kanlaon Nyiragongo Talang
Cereme Karangetang Okataina Tambora
Chachadake [Tiatia] Karkar Okmok Tanaga
Chaiten Karthala Ontakesan Tandikat-Singgalang
Chiginagak Karymsky Oraefajokull Tangkoko-Duasudara
Chikurachki Kasatochi Osorno Tangkubanparahu
Chiles-Cerro Negro Katla Pacaya Tara, Batu
Chillan, Nevados de Kavachi Pagan Telica
Chirinkotan Kelimutu Palena Volcanic Group Tenerife
Chirpoi Kelut Paluweh Tengger Caldera
Cleveland Kerinci Panarea Three Sisters
Colima Ketoi Papandayan Tinakula
Colo Kharimkotan Parker Tofua
Concepcion Kick 'em Jenny Pavlof Tokachidake
Copahue Kikai Peuet Sague Tolbachik
Cotopaxi Kilauea Pinatubo Toliman
Cuicocha Kirishimayama Planchon-Peteroa Tongariro
Cumbal Kizimen Poas Tungurahua
Dabbahu Klyuchevskoy Popocatepetl Turrialba
Dempo Kolokol Group Puyehue-Cordon Caulle Ubinas
Descabezado Grande Korovin Rabaul Ulawun
Dieng Volcanic Complex Koryaksky Raikoke Unknown Source
Dukono Krakatau Ranakah Unnamed
Ebeko Krummel-Garbuna-Welcker Raoul Island Unnamed
Ebulobo Kuchinoerabujima Rasshua Veniaminof
Egon Kurikomayama Raung Villarrica
Ekarma Kusatsu-Shiranesan Redoubt West Mata
Epi Kverkfjoll Reventador White Island
Erebus Lamington Rincon de la Vieja Witori
Erta Ale Lamongan Rinjani Wolf
Etna Langila Ritter Island Yasur
Etorofu-Yakeyama [Grozny Group] Lanin Rotorua Zaozan
Eyjafjallajokull Lascar Ruang Zavodovski
Fernandina Lengai, Ol Doinyo Ruapehu Zhupanovsky
Fogo Leroboleng Ruiz, Nevado del Zubair Group
Fonualei Lewotobi Sabancaya
Fournaise, Piton de la Lewotolo Sakar
Fourpeaked Little Sitkin Salak
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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

Criteria

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.


Disclaimers

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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URL https://volcano.si.edu/reports_weekly.cfm
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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)