All times are local unless otherwise stated.

Sheveluch | 2 May-8 May 2001 | New Activity / Unrest Cite this Report
Sheveluch Central Kamchatka (Russia)	Volcanic activity continued at high levels at Shiveluch, with an increase in seismic activity, a thermal anomaly visible in satellite imagery, several small explosions, and a small pyroclastic-flow-producing eruption. An increase in seismic activity occurred on 1 May following the initial increase on 22 April and subsequent slight decrease on 28 April. The seismic activity increase on 1 May consisted of many shallow earthquakes and episodes of weak spasmodic tremor. Several small eruptions produced gas-and-steam plumes that rose up to 1.5 km. AVO reported that on 2 May a weak thermal anomaly (3 pixels) that was originally detected on 30 April was visible on satellite imagery. By 3 May the thermal anomaly had increased in intensity, with 2 of the 3-4 pixels at or near saturation on the imagery. At 0958 on 7 May an eruption produced an ash-and-gas plume that rose ~4.5 km a.s.l. and extended to the NW. Small pyroclastic flows were visible traveling down the volcano's SW slope. The Concern Color Code at Shiveluch remained at Orange. Sources: Tokyo Volcanic Ash Advisory Center (VAAC), Kamchatkan Volcanic Eruption Response Team (KVERT)
Three Sisters | 2 May-8 May 2001 | New Activity / Unrest Cite this Report
Three Sisters Oregon	The USGS Cascades Volcano Observatory reported on 8 May that between 1996 and 2000 they detected slight uplift of the ground surface over a broad area 5 km W of South Sister volcano. The uplift occurred over an area ~15-20 km in diameter and the maximum amount of uplift at its center is ~10 cm. CVO personnel believe the uplift may reflect intrusion of a small volume of magma at ~7 km depth beneath the ground surface. They stated that if the intrusion of magma continues it could eventually lead to a volcanic eruption, but precursory activity would most likely occur beforehand. There is no precursory activity that suggests an eruption is imminent; seismic activity at the volcano is near or below background levels, gas emissions are low, and no unusual surface changes have been observed. Sources: US Geological Survey Cascades Volcano Observatory (CVO), Associated Press
Ulawun | 2 May-8 May 2001 | New Activity / Unrest Cite this Report
Ulawun New Britain (Papua New Guinea)	Based on information from the Rabaul Volcanological Observatory, the Darwin VAAC stated that no eruptions of Ulawun had been reported since the 30 April event, though cloudy conditions have inhibited clear views of the volcano. Limited evacuations occurred on 3 May due to the possibility of further volcanic activity. Ulawun is at stage 2 alert. Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Cleveland | 2 May-8 May 2001 | Continuing ActivityCite this Report
Cleveland Chuginadak Island (USA)	Volcanic unrest continued at Cleveland through 4 May. The volcano was obscured by clouds during the report period and no thermal anomalies were observed. Pulses of volcanic tremor continued to be detected by an AVO seismic network 230 km to the E of the volcano. AVO personnel installed a temporary seismic-recording instrument at Nikolski, ~70 km to the E of the volcano, in an attempt to verify that the source of the tremor is Cleveland. AVO had received no reports of significant volcanic activity from either pilots, residents, or satellite remote-sensors since the last eruption on 19 March. Source: US Geological Survey Alaska Volcano Observatory (AVO)
Etna | 2 May-8 May 2001 | Continuing ActivityCite this Report
Etna Sicily (Italy)	Sistema Poseidon reported that during 30 April to 6 May degassing occurred at Bocca Nuova, Southeast, and Voragine craters. In addition to degassing, ash was emitted from Bocca Nuova crater, although after 3 May the emissions became more sporadic. Lava continued to flow from the northern vent on Southeast Crater and hornitos were formed in the area. Source: Sezione di Catania - Osservatorio Etneo (INGV)
Ijen | 2 May-8 May 2001 | Continuing ActivityCite this Report
Ijen Eastern Java	During 23-29 April seismic activity was higher than normal at Ijen, with a high number of shallow volcanic earthquakes (nine). In addition, one small explosion event and seven tectonic earthquakes were recorded. Visual observations were not possible. 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)
Karangetang | 2 May-8 May 2001 | Continuing ActivityCite this Report
Karangetang Sangihe Islands	During 23-29 April Karangetang Observatory personnel observed lava flowing from Karangetang's main crater to a maximum distance of 700 m. A possible steam plume rose 500 m above the main crater. No seismic data were available. Karangetang remained at Alert Level 2 (on a scale of 1-4). Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)
Kilauea | 2 May-8 May 2001 | Continuing ActivityCite this Report
Kilauea Hawaiian Islands (USA)	Small streams of lava traveled down the Pulama Pali fault scarp. On 6 May lava was visible entering the sea at three locations and producing small steam plumes. The swarm of long-period earthquakes that occurred beneath the caldera the previous week came to an end. Generally, earthquake activity and volcanic tremor near Pu`u `O`o and in Kilauea's caldera were at 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)
Marapi | 2 May-8 May 2001 | Continuing ActivityCite this Report
Marapi Central Sumatra	VSI reported that volcanic activity continued at Marapi at a decreased level in comparison to the previous week. Thirty explosions were observed and an ash plume rose 3 km above the summit. Tephra fell up to 4 km in radius from the crater. Marapi remained at Alert Level 2 (on a scale of 1-4). Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)
Mayon | 2 May-8 May 2001 | Continuing ActivityCite this Report
Mayon Luzon (Philippines)	At 1848 on 7 May an explosion occurred at Mayon that was recorded by the seismic network on the volcano, but was not observed due to cloudy conditions. After the eruption, faint incandescence was visible at the crater with the naked eye during 1915-1945; the incandescence was graded as level 2 intensity. During the week ending on 29 April there had been a total of 33 low-frequency earthquakes and 12 high-frequency short-duration harmonic tremors. The SO2 flux during the same period averaged 3,100 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. The crater was visible, but no glow was observed. Alert Level 3 remained in effect, prohibiting entry within the 6-km-radius permanent danger zone. Source: Philippine Institute of Volcanology and Seismology (PHIVOLCS)
Merapi | 2 May-8 May 2001 | Continuing ActivityCite this Report
Merapi Central Java	Activity at Merapi increased during 23-29 April, with reports of several medium-sized pyroclastic flows. Four pyroclastic flows were observed traveling into the upper reaches of the Sat, Senowo, Lamat, and Bebeng rivers, with a maximum runout distance of 1.8 km in the Sat River. Lava avalanches traveled up to 2.5 km down the Sat River. Superficial earthquakes continued to dominate the seismicity. 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 | 2 May-8 May 2001 | Continuing ActivityCite this Report
Popocatepetl Mexico	Several small exhalations at Popocatépetl produced small plumes of steam and ash with the largest plume rising up to 1.5 km above the crater. The volcano remained at Alert Level Yellow Phase III, with a restricted 12-km-radius area. Sources: Centro Nacional de Prevencion de Desastres (CENAPRED), Washington Volcanic Ash Advisory Center (VAAC), Associated Press
Semeru | 2 May-8 May 2001 | Continuing ActivityCite this Report
Semeru Eastern Java	Volcanic activity increased at Semeru in comparison to the previous week. Seismographs recorded 759 explosion events (550 last week), 157 avalanche events, and four 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)
Soufriere Hills | 2 May-8 May 2001 | Continuing ActivityCite this Report
Soufriere Hills Montserrat	MVO reported that during 27 April- 4 May volcanic activity at Soufrière Hills remained low, although there was a slight increase during 28 and 29 April. An increase in rockfall activity occurred from 28 April to 1 May; there were 16 rockfalls on 29 April, 34 on 30 April, and 15 on 1 May. For the previous six weeks there had usually been less than 10 rockfalls per day. The increase in activity may have been due to heavy rain on 29 and 30 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 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)
Tungurahua | 2 May-8 May 2001 | Continuing ActivityCite this Report
Tungurahua Ecuador	Moderate levels of volcanic activity continued at Tungurahua, with small steam-and-ash transmissions occurring. Seismic activity indicated that a lahar may have traveled down the flanks of the volcano on 3 May. Source: Instituto Geofísico-Escuela Politécnica Nacional (IG-EPN)

Weekly Reports Archive

Since the Weekly Volcanic Activity Report began in November 2000, there have been 19,996 individual reports over 1,215 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.

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)