All times are local unless otherwise stated.

San Cristobal (Nicaragua) | 16 May-22 May 2001 | New Activity / Unrest Cite this Report
San Cristobal Central America Volcanic Arc	Volcanic activity increased at San Cristóbal on 17 May, accompanied by a relatively large amount of seismic tremor. Pulses of gas-and-ash emissions were observed rising up to 100 m above the rim of the volcano's crater. Light ash fell in the town of Santa Barbara, 14 km SW of the volcano. Sources: El Nuevo Diario, Instituto Nicaragüense de Estudios Territoriales (INETER), ABC News - Australian Broadcasting Corporation
Sheveluch (Russia) | 16 May-22 May 2001 | New Activity / Unrest Cite this Report
Sheveluch Eastern Kamchatka Volcanic Arc	Due to the occurrence of several large explosions at Shiveluch, KVERT increased the Concern Color Code to Red on 21 May. An approximately 40-minute-long eruption began at 1556 on 19 May. An ash cloud rose to an altitude of 10 km a.s.l. and drifted to the NE. Short pyroclastic flows and hot avalanches from the lava dome were restricted to areas near the lava dome. At 1802 and 1814 on 20 May a large thermal anomaly was visible on satellite imagery. At 1925 and 2014 two explosions sent ash columns to heights ranging between 4.7 and 5 km a.s.l. At 0713 on 21 May an explosion sent an ash column to 10-12 km a.s.l. AVO reported that ash was visible on satellite imagery. At 0209 on 22 May an eruption produced a mushroom-shaped ash column to a height of ~20 km a.s.l. that drifted to the SSE. Reflected incandescence was observed above the volcano from the town of Klyuchi, 46 km from the volcano. The Concern Color Code changed several times during the week; on 19 May it was raised from Yellow to Red, on 20 May it was reduced to Yellow, and the following day it was raised again to Red. Sources: Anchorage Volcanic Ash Advisory Center (VAAC), Tokyo Volcanic Ash Advisory Center (VAAC), Kamchatkan Volcanic Eruption Response Team (KVERT)

Cleveland (United States) | 16 May-22 May 2001 | Continuing ActivityCite this Report
Cleveland Aleutian Ridge Volcanic Arc	Cleveland was observed on satellite images numerous times during the week and no thermal anomalies were detected. AVO had received no reports of significant volcanic activity from pilots, residents, or satellite remote-sensors since the last eruption on 19 March. Source: US Geological Survey Alaska Volcano Observatory (AVO)
Etna (Italy) | 16 May-22 May 2001 | Continuing ActivityCite this Report
Etna Sicily Volcanic Province	According to the Italy's Volcanoes website, mild eruptive activity continued at Southeast Crater, with persistent lava outflow from a vent on the NNE flank of its cone. Very weak Strombolian bursts occurred at the summit vent of the cone that occasionally sent incandescent bombs up to 100 m above the crater rim. A Spanish tourist who visited the volcano alone has been missing since 14 May and is presumed dead. The remains of her tent were found on 18 May near the rim of Bocca Nuova crater. Local press sources reported that a rescue team found footprints leading from the tent to the rim of one of the two active pits within the crater, but no prints were found leading back from the pit. It is possible that the tourist was standing on the rim of the pit when a portion of it broke loose. Source: Italy's Volcanoes
Fujisan (Japan) | 16 May-22 May 2001 | Continuing ActivityCite this Report
Fujisan Izu Volcanic Arc	Based on information from JMA, VRC reported that 67 earthquakes occurred at Mt. Fuji on 30 April, which was the highest number since 53 earthquakes occurred on 18 December 2000. Activity had been relatively low since January 2001. During 3-9 May ~130 predominately low-frequency earthquakes occurred that were located ~15 km beneath an area just NE of the volcano's summit. No other anomalous volcanic activity was observed by NIED. Source: Volcano Research Center-Earthquake Research Institute (University of Tokyo)
Kilauea (United States) | 16 May-22 May 2001 | Continuing ActivityCite this Report
Kilauea Hawaiian-Emperor Hotspot Volcano Group	Lava continued to flow down Pulama pali and was observed entering the sea at the SE corner of the lava flow field. On 20 May the largest tilt event to occur at Kilauea in more than 4 years took place. Beginning at 0500 the volcano's summit began to slowly deflate (~2 microradians) until about 1630 when it very abruptly began to inflate (~10 microradians). The inflation peaked at 1735, and deflation began at 1750. The event was accompanied by strong tremor, which ended a prolonged period of small earthquakes that had lasted, with a 9-hour break on the night of 18 May, for several days. At about 1920 a lava pond was observed forming in Pu`u `O`o crater. Observations the next day revealed that the pond had drained, leaving only a few spattering vents. Source: US Geological Survey Hawaiian Volcano Observatory (HVO)
Lokon-Empung (Indonesia) | 16 May-22 May 2001 | Continuing ActivityCite this Report
Lokon-Empung Sangihe Volcanic Arc	An article in the Jakarta Post stated that an eruption at Lokon that began at 2014 on 20 May deposited ash in a wide area around the volcano, including the provincial capital of Manado, approximately 20 km NE of the volcano. They reported that ash rose up to 900 m above the volcano and that the eruption was accompanied by tremor. Source: The Jakarta Post
Mayon (Philippines) | 16 May-22 May 2001 | Continuing ActivityCite this Report
Mayon Eastern Philippine Volcanic Arc	Elevated levels of volcanic activity continued at Mayon. Rockfalls were produced from fragments that were shed off of the summit lava dome. Seismic activity was relatively low. SO2 emission rates were at a very high level of ~7,400 metric tons per day, which is significantly above the baseline value of 500 tons/day. Moderate steaming occurred and Intensity I (faint) and II (fair, visible with the naked eye) incandescence was occasionally observed at the crater. Weak-to-moderate ash-and-steam venting occurred from the lava dome. Electronic distance meter (EDM) data indicated a general, but minor, inflation of the volcanic edifice. Alert Level 3 remained in effect, prohibiting entry within the 6-km-radius permanent danger zone. PHIVOLCS warned that residents around the volcano, especially those staying in areas facing the Bonga Gully and the SE sector, should be vigilant and prepared to evacuate at any time. Sources: Philippine Institute of Volcanology and Seismology (PHIVOLCS), Associated Press
Miyakejima (Japan) | 16 May-22 May 2001 | Continuing ActivityCite this Report
Miyakejima Izu Volcanic Arc	Based on information from the JMA, VRC reported that no ash clouds had been observed at Miyake-jima since the 19 March eruption. They also reported that steam plumes with abundant SO2 were continuously emitted from the summit caldera to 0.5-2 km above the caldera rim. Continuous SO2 emission released as much as 33,000 to 46,000 tons of SO2 per day. Low-level seismic activity continued and a M 2.8 earthquake occurred on 7 May. Global positioning system (GPS) measurements showed steady, continuous deflation of the volcano though the rate was lower than before September 2000. During air inspections very small collapses of the caldera rims were occasionally seen. Source: Volcano Research Center-Earthquake Research Institute (University of Tokyo)
Okmok (United States) | 16 May-22 May 2001 | Continuing ActivityCite this Report
Okmok Aleutian Ridge Volcanic Arc	AVO reported that the earthquake swarm centered near Okmok that was first detected on 11 May greatly diminished by 15 May. Source: US Geological Survey Alaska Volcano Observatory (AVO)
Popocatepetl (Mexico) | 16 May-22 May 2001 | Continuing ActivityCite this Report
Popocatepetl Trans-Mexican Volcanic Arc	Small-to-moderate sized exhalations consisting mostly of gas and steam occurred at Popocatépetl during the week. Source: Centro Nacional de Prevencion de Desastres (CENAPRED)
Soufriere Hills (United Kingdom) | 16 May-22 May 2001 | Continuing ActivityCite this Report
Soufriere Hills Lesser Antilles Volcanic Arc	MVO reported that during 11-18 May volcanic activity increased, with about twice the number of rockfalls than the previous week. Most of the rockfalls were small and were observed to the SW of the summit, N of the town of Galway's. Growth of the lava dome was concentrated in the S sector of the volcano above White River. A new lobe of lava was observed in the area, although the rate of growth appeared to be low. Sulfur dioxide flux remained low. Most of Montserrat received very light ashfall throughout the week as a result of changeable winds. Source: Montserrat Volcano Observatory (MVO)
Tungurahua (Ecuador) | 16 May-22 May 2001 | Continuing ActivityCite this Report
Tungurahua Northern Andean Volcanic Arc	Volcanic activity increased slightly at Tungurahua during the week. On 15 May several small eruptions occurred, with the largest sending ash up to 3 km above the summit. Light ash fell in the towns of Cotaló and Bilbao. The Washington VAAC reported that an eruption that began around 1830 on 17 May sent an ash cloud to ~9 km a.s.l. that drifted to the SW. According to IG on 17 and 18 May Tungurahua was not visible due to cloudy conditions, but intense activity was indicated by the high number of long-period earthquakes and seismic signals that may have been associated with eruptions. At 0615 on 19 May an eruption produced an ash cloud that rose ~6.7 km a.s.l. IG warned that lahars might be generated if rainfall mixed with ash deposited on the upper W flanks of the volcano. Sources: Washington Volcanic Ash Advisory Center (VAAC), Instituto Geofísico-Escuela Politécnica Nacional (IG-EPN)

Weekly Reports Archive

Since the Weekly Volcanic Activity Report began in November 2000, there have been 21,469 individual reports over 1,278 weeks (average of 17 per week) on 339 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.

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.

For site security purposes and to ensure that this service remains available to all users, this government computer system employs software programs to monitor network traffic to identify unauthorized attempts to upload or change information, or otherwise cause damage. Unauthorized attempts to upload information or change information on this website are strictly prohibited and may be punishable under the Computer Fraud and Abuse Act of 1986 and the National Information Infrastructure Protection Act. Information may also be used for authorized law enforcement investigations. (Last modified September 21, 1999.)

U.S. Department of the Interior, U.S. Geological Survey, Reston, VA, USA
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)