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Smithsonian / USGS Weekly Volcanic Activity Report

You are currently viewing Archived reports for the week of 11 April-17 April 2001.


















 Activity for the week of 11 April-17 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
Jackson Segment Gorda Ridge New

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


New Activity / Unrest


Jackson Segment  | Gorda Ridge  | 42.15°N, 127.05°W  | Elevation -3100 m

Scientists from NOAA used the T-phase Monitoring System to search for megaplumes from a possible eruption of the Jackson Segment of the Gorda Ridge that began on 3 April. They did not find evidence of a plume after collecting 25 vertical hydrographic casts during 11-16 April. Two bottom camera tows were also collected, but the film had not been developed at the time of this report. By 11 April seismic activity was at very low levels, possibly below the detection threshold of the T-phase Monitoring System.

Source: NOAA Vents Program



Ongoing Activity


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

During 2-9 April, thin steam plumes were observed rising from Batur's crater. Seismographs recorded one deep volcanic earthquake, two shallow volcanic earthquakes, ten tectonic earthquakes, and five small explosion events. Batur is 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 13 April. A thermal anomaly was last detected on satellite imagery on 8 April, but cloudy conditions in the area may have hidden the anomaly from the satellite's view during the rest of the week. 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 2-8 April Strombolian activity continued at Bucca Nuova crater. In addition, degassing of the crater was accompanied by ash emissions. Lava continued to flow from a fissure on the NE flank of Southeast Crater. Lava also flowed from a 6-m-high tumulus that formed on the N flank of the volcano at an elevation of approximately 3,095 m. Voragine and Northeast craters continued degassing at low levels.

Source: Sezione di Catania - Osservatorio Etneo (INGV)



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

Seismic activity at Ijen was high during 2-9 April. Five episodes of tremor were reported. The number of shallow volcanic earthquakes decreased in comparison to the previous week. Overall, seismographs recorded 13 shallow volcanic earthquakes, two tectonic earthquakes, and one small explosion event. The volcano is 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  Karangetang  | Siau Island (Indonesia)  | 2.781°N, 125.407°E  | Elevation 1797 m

Observers noted that during 2-9 April a plume, which may have contained ash, rose 25-400 m above the volcano and a steam plume rose 200 m above crater II. A red-colored reflection was visible rising 25-75 m above the volcano. No seismic data were available. 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  Kelut  | Eastern Java (Indonesia)  | 7.93°S, 112.308°E  | Elevation 1731 m

VSI reported that there were no major changes in volcanic activity at Kelut during 2-9 April. The temperature of the water in the crater lake decreased slightly. On 2 April the lake was at 48.5°C and on 9 April it was at 48°C. 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

After phases of deflation, inflation, and increased seismicity last week, volcanic activity at Kilauea returned to normal levels. Lava flowed down the Pulama pali and several surface flows were visible on the coastal flat. By 15 April surface lava flows seemed to diminish. Generally, volcanic tremor near Pu`u `O`o cone and in Kilauea's caldera was at a low levels. 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 8 April there had been a total of 116 low-frequency volcanic earthquakes, six high-frequency volcanic earthquakes, and three 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. During most of the week no glow was observed at the crater, except during 1915 to 2223 on 10 April when faint incandescence was observed at the crater using a telescope; 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

Visual and instrumental monitoring by VSI personnel during 2-9 April revealed that volcanic activity continued at Merapi. Lava avalanches continued to enter upstream areas of the Sat, Senowo, Lamat, and Bebeng rivers, with a maximum runout distance of 2.5 km in the Sat River. An observer reported that ten pyroclastic flows traveled down the Sat, Senowo, and Bebeng rivers, reaching as far as 2.3 km in the Sat River. Fumaroles emitted steam and gas up to 950 m above the volcano's summit. Both the number and amplitude of earthquakes was high, but less than previously recorded. Seismic activity was dominated by avalanche 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  Popocatepetl  | Mexico  | 19.023°N, 98.622°W  | Elevation 5393 m

Several small-to-moderate exhalations occurred during the week at Popocatéptl. CENAPRED reported that at 1948 on 16 April a moderate explosion sent incandescent fragments up to 2 km away from the volcano's crater to the NE and NW and produced an ash plume that rose 4 km above the crater and drifted to the SW. The 40-second-long eruption partially destroyed the lava dome that had formed within the crater over the course of several weeks. 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  Rotorua  | North Island (New Zealand)  | 38.08°S, 176.27°E  | Elevation 757 m

A vent in Kuirau Park in Rotorua ejected a small amount of hot mud, most likely on 8 April.

Source: GeoNet



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

There was a significant increase in the number of earthquakes detected at Semeru during 2-9 April following a decrease in volcanic activity during the previous several weeks. Seismographs recorded 28 deep volcanic earthquakes, 305 explosion events, 248 avalanche events, and 3 tectonic earthquakes. Cloudy conditions prohibited visual observations. 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

Seismicity was at background levels during 6-13 April. Short series of separate, shallow earthquakes and episodes of volcanic tremor were registered during the week. Some of the seismic events may have corresponded to weak ash-and-gas and steam-and-gas explosions. During 6-8 April a gas-and-steam plume rose 500-800 m above the volcano and extended 5-10 km to the E. At 1500 on 7 April a gas-and-steam plume rose up to 1.2 km above the volcano. The Concern Color Code remained at Yellow.

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 6-13 April volcanic activity at Soufrière Hills remained low. Seismic and rockfall activity were low and there was a small amount of growth on the S side of the lava dome. Sulfur dioxide flux also remained low. MVO warned that although activity is low, dangerous conditions can develop quickly and in the event of heavy rain the Belham Valley to the NE of the volcano should be avoided due to the possibility of mudflows.

Source: Montserrat Volcano Observatory (MVO)



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

Based on information from IG, the Washington VAAC reported that two small eruptions produced ash clouds that rose ~7 km a.s.l. and blew towards the W; one at 1530 on 14 April, and the other at 1140 on 15 April. The ash clouds were not visible on satellite imagery.

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



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Chirpoi Kelimutu Paluweh Tengger Caldera
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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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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)