All times are local unless otherwise stated.

St. Helens | 31 October-6 November 2001 | New Activity / Unrest Cite this Report

St. Helens Washington

Beginning on 2 November at about 1800 a swarm of approximately 200 very small, shallow earthquakes was detected for at least 24 hours beneath Mount St. Helens. The earthquakes had magnitudes less than 0, occurred at depths less than 1 km, and were mostly in or under the lava dome's N flank. Such earthquakes are common at Mount St. Helens, but a swarm with so many earthquakes had not been recorded for several years. Cascades Volcano Observatory (CVO) scientists were uncertain what caused the earthquakes, but they suggested that increasing ground water levels due to autumn rain could have caused slippage on fractures in and below the lava dome and crater floor. CVO stated that the probability of small landslides, debris flows in the crater, and steam explosions is enhanced during these periods. Larger-scale eruptions are unlikely without significant additional precursory activity. Sources: Seattle Post-Intelligencer, US Geological Survey Cascades Volcano Observatory (CVO)

Avachinsky | 31 October-6 November 2001 | Continuing ActivityCite this Report
Avachinsky Eastern Kamchatka (Russia)	During 26 October to 2 November seismicity was at background levels, with only weak earthquakes detected (magnitudes less than or equal to 1.2). During 29 October to 1 November, when the volcano was visible, weak-to-powerful gas-and-steam emissions were observed extending to the SE and E. The Concern Color Code was reduced from Yellow to Green. Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
Colima | 31 October-6 November 2001 | Continuing ActivityCite this Report
Colima Mexico	The Universidad de Colima reported on 4 November that significant deformation had been registered at Colima. Seismicity remained low and there was little visibility at the volcano. Source: Centro Universitario de Estudios Vulcanológicos (CUEV) - Universidad de Colima
Iliwerung | 31 October-6 November 2001 | Continuing ActivityCite this Report
Iliwerung Lembata Island	An increase in tectonic earthquakes around Iliwerung during 17-26 October led VSI to raise the Alert Level from 1 to 2 (on a scale of 1-4). From 2 to 11 earthquakes were felt per day with Modified Mercalli intensities of I-II. Visual and instrumental monitoring did not show a significant change in volcanic activity. Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)
Karangetang | 31 October-6 November 2001 | Continuing ActivityCite this Report
Karangetang Sangihe Islands	On 29 October at 0029 an explosion from Crater IV, in the southern portion of the main crater, produced a gray cloud that rose 1.5 km above the crater. During 22-28 October white plumes rose 600 m above main crater, and 50-100 m above Crater II. A "red reflection" was observed reaching up to 75 m above the crater. The number of deep volcanic earthquakes increased compared to the previous week, but no seismicity associated with eruptive activity was recorded. Multiphase earthquakes, associated with lava dome growth, continued to be detected. 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)
Kilauea | 31 October-6 November 2001 | Continuing ActivityCite this Report
Kilauea Hawaiian Islands (USA)	During 30 October to 5 November lava continued to flow into the sea at the Kamoamoa and E Kupapa`u entries. On 30 October a new entry located directly off the former Kupapa`u Point was observed. Surface lava flowed above and down Pulama pali along the trace of the Kamoamoa lava tube system. There were possible surface flows at the western portion of the Kamoamoa entry, while surface activity ended at the eastern portion. Generally, volcanic tremor remained at low-to-moderate levels at Kilauea's summit and Pu`u `O`o. Tremor was relatively low at the summit; tiny earthquakes occurred that were strongest during the beginning of the week. Bursts of higher amplitude tremor were interspersed with more continuous tremor at Pu`u `O`o. Tiltmeters across the volcano showed no significant deformation. Source: US Geological Survey Hawaiian Volcano Observatory (HVO)
Merapi | 31 October-6 November 2001 | Continuing ActivityCite this Report
Merapi Central Java	During 22-28 October, VSI personnel observed 121 incandescent lava avalanches traveling SW predominately to the upstream portion of the Sat River, and to a lesser extent to the Lamat and Senow rivers. The maximum run-out distance was 2.75 km. On 24 October four minor pyroclastic flows were observed travelling a maximum distance of 2 km to the upstream portions of the Sat and Senowo rivers. Seismicity was dominated by avalanche earthquakes similar in magnitude and frequency to earthquakes the previous week. Merapi remained at Alert Level 2 (on a scale of 1-4). Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)
Popocatepetl | 31 October-6 November 2001 | Continuing ActivityCite this Report
Popocatepetl Mexico	Volcanic activity remained low at Popocatépetl, with emissions of small clouds of steam, gas, and minor amounts of ash. Episodes of low-amplitude harmonic tremor also occurred. An aerial photograph of the crater was taken on 25 October by the Dirección General de Carreteras Federales, SCT. It showed that the lava dome, which was first reported on 20 September 2001, had subsided. In addition, a new, small 50-m-diameter lava dome had grown in the bottom of the internal crater. According to CENAPRED, a similar situation had been observed in April 2001 and the presence of the lava dome indicates the possibility of small explosions occurring in the next days to weeks. The volcano remained at Alert Level Yellow Phase II. Sources: Centro Nacional de Prevencion de Desastres (CENAPRED), Washington Volcanic Ash Advisory Center (VAAC)
Sheveluch | 31 October-6 November 2001 | Continuing ActivityCite this Report
Sheveluch Central Kamchatka (Russia)	During 26 October-2 November, a lava dome continued to grow in Shiveluch's active crater. The evening of 29-30 October incandescent avalanches were observed travelling down the W and SW slopes of the lava dome. Gas-and-steam plumes rose ~1.5 km above the dome on 30 and 31 October. Thermal anomalies in the active dome area were visible on satellite imagery. Spasmodic volcanic tremor and weak, shallow seismic signals (possible collapses and avalanches) were registered. The intensity of volcanic tremor was greater than the previous week. Shiveluch remained at Concern Color Code Orange. Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
Soufriere Hills | 31 October-6 November 2001 | Continuing ActivityCite this Report
Soufriere Hills Montserrat	Beginning on 26 October, seismicity at Soufrière Hills was at low levels until it increased on 1 November. Clear weather conditions allowed observations of the lava dome on 31 October and 1 November. The active lava dome had grown substantially and appeared to switch growth direction from the NE to the E, where a massive, near-vertical headwall had developed. Several small pyroclastic flows were generated by material avalanching off the eastern flank of the dome. Cycles of mostly hybrid earthquakes, with a coincident increase in rockfalls, were weak until they strengthened on 1 November. Mudflows occurred in the Belham Valley during several days with periods of torrential rainfall. Source: Montserrat Volcano Observatory (MVO)
Tungurahua | 31 October-6 November 2001 | Continuing ActivityCite this Report
Tungurahua Ecuador	IG reported that during the morning of 1 November three emissions of steam and ash were observed rising 1 to 2 km above Tungurahua's summit and drifting to the E and NE. According to the Washington VAAC, no ash was visible on satellite imagery at 0545, although any significant ash would have been visible. On 2 November there was a small increase in the number of long-period events and steam-and-ash emissions. Sources: Instituto Geofísico-Escuela Politécnica Nacional (IG-EPN), Washington Volcanic Ash Advisory Center (VAAC), El Comercio

Weekly Reports Archive

Since the Weekly Volcanic Activity Report began in November 2000, there have been 19,584 individual reports over 1,195 weeks (average of 16 per week) on 332 different volcanoes.

Use the dropdowns to choose the year and week for archived Weekly Reports.

 News Feeds and Google Placemarks

 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 cover longer time periods and are 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.

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

 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)