Smithsonian / USGS Weekly Volcanic Activity Report

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 and averaging 16 reported volcanoes, this is not a comprehensive list of all eruptions this week, but rather a summary of activity that meet criteria discussed in the "Criteria and Disclaimers" section below.

Volcanic activity reported here is preliminary and subject to change. Carefully reviewed, detailed narratives over longer time periods are published as reports of the Bulletin of the Global Volcanism Network available through volcano profile pages.

Smithsonian / USGS Weekly Volcanic Activity Report for the week of 14 April-20 April 2021
Name	Country	Volcanic Province	Eruption Start Date	Report Status
Fagradalsfjall	Iceland	Iceland Neovolcanic Rift Volcanic Province	—	New
Karymsky	Russia	Eastern Kamchatka Volcanic Arc	2024 Jun 20	New
Piton de la Fournaise	France	Reunion Hotspot Volcano Group	—	New
Semisopochnoi	United States	Aleutian Ridge Volcanic Arc	—	New
Soufriere St. Vincent	Saint Vincent and the Grenadines	Lesser Antilles Volcanic Arc	—	New
Aira	Japan	Ryukyu Volcanic Arc	2017 Mar 25	Continuing
Dukono	Indonesia	Halmahera Volcanic Arc	1933 Aug 13	Continuing
Ebeko	Russia	Kuril Volcanic Arc	2022 Jun 11	Continuing
Kadovar	Papua New Guinea	Bismarck Volcanic Arc	—	Continuing
Kilauea	United States	Hawaiian-Emperor Hotspot Volcano Group	2024 Sep 15	Continuing
Lewotolok	Indonesia	Sunda Volcanic Arc	—	Continuing
Merapi	Indonesia	Sunda Volcanic Arc	2020 Dec 31	Continuing
Popocatepetl	Mexico	Trans-Mexican Volcanic Belt	2005 Jan 9	Continuing
Raung	Indonesia	Sunda Volcanic Arc	—	Continuing
Sabancaya	Peru	Central Andean Volcanic Arc	2016 Nov 6	Continuing
Sangay	Ecuador	Northern Andean Volcanic Arc	2019 Mar 26	Continuing
Semeru	Indonesia	Sunda Volcanic Arc	2017 Jun 6	Continuing
Sheveluch	Russia	Eastern Kamchatka Volcanic Arc	1999 Aug 15	Continuing
Sinabung	Indonesia	Sunda Volcanic Arc	—	Continuing
Suwanosejima	Japan	Ryukyu Volcanic Arc	2004 Oct 23	Continuing
Tanaga	United States	Aleutian Ridge Volcanic Arc	—	Continuing
Ugashik-Peulik	United States	Alaska Peninsula Volcanic Arc	—	Continuing
Ukinrek Maars	United States	Alaska Peninsula Volcanic Arc	—	Continuing

All times are local unless otherwise stated.

Fagradalsfjall (Iceland) | 14 April-20 April 2021 | New Activity / Unrest Cite this Report

Fagradalsfjall
Iceland Neovolcanic Rift Volcanic Province

IMO reported that the fissure eruption in the W part of the Krýsuvík-Trölladyngja volcanic system, close to Fagradalsfjall on the Reykjanes Peninsula, continued during 14-20 April. Lava flowed from about eight vents and the flow field continued to expand; on 14 April a new hiking trail (“A”) had been covered. Volcanic gas emissions were at dangerous levels during 14-15 April so the eruption site was closed to the public. At about 1500 on 17 April a new vent was confirmed to have opened. It was small and close to another crater, possibly the one that had opened on 13 April. Lava was not flowing from the northernmost crater (the first that had opened outside Geldingadalur) during 18-20 April.

The eruption had been ongoing for 30 days by 17 April. Based on a report from University of Iceland’s Institute of Earth Sciences, the average lava-flow rate during the first 17 days of the eruption was 4.5-5 cubic meters per second but had increased to 7 cubic meters per second over the previous 13 days. During 12-18 April the flow rate was closer to 8 cubic meters per second, a slight increase over the recent average. By 19 April the area of the flow field was 0.9 square kilometers and the total volume was over 14 million cubic meters.

IMO warned visitors that new fissures could open without adequate visible warning, especially in an area by Litla-Hrút, just S of Keilir, `where seismicity was concentrated. They also warned of increased gas emissions hazards. The Aviation Color Code remained Orange due to the lack of ash and tephra emissions.

Source: Icelandic Meteorological Office (IMO)

Karymsky (Russia) | 14 April-20 April 2021 | New Activity / Unrest Cite this Report

Karymsky
Eastern Kamchatka Volcanic Arc

KVERT reported that a thermal anomaly over Karymsky was visible in satellite images during 9-12 April; weather conditions obscured views during 13-16 April. An explosion at 1745 on 11 April produced ash plumes that rose to 4 km (13,100 ft) a.s.l. and drifted 112 km SSE. The Aviation Color Code remained at Orange (the second highest level on a four-color scale).

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Piton de la Fournaise (France) | 14 April-20 April 2021 | New Activity / Unrest Cite this Report

Piton de la Fournaise
Reunion Hotspot Volcano Group

OVPF reported that the eruption at Piton de la Fournaise continued during 14-20 April. Lava fountaining was visible from both cones on most days, though sometimes inclement weather prevented visual observations of the eruption site. During an overflight on 16 April scientists observed that the most distal part of the lava flows had stopped advancing. The larger and more northern cone was 28 m high. The cone at a lower elevation, about 100 m away, had two vents. The smaller cone fed lava flows that traveled though tubes and emerged after 100 m, continuing to advance as many surficial breakout flows. The total length of the flow field was about 3.5 km and the maximum width was 750 m.

Sulfur dioxide emissions gradually increased between 400 and 859 tonnes per day during 9-12 April, peaked at 4,054 tonnes per day on 13 April, and then dropped to 2,100 tonnes per day on 14 April. OVPF estimated lava-flow rates based on the gas-emission rates, noting that weather conditions could affect the accuracy of the measurements. They estimated that the average flow rate in cubic meters per second was 20 during 9-10 April, an average of 24 with a maximum value of 59 on 13 April, 12.5 on 14 April, and 6.5-8.3 during 16-19 April. The Alert Level was raised to 2-2.

Source: Observatoire Volcanologique du Piton de la Fournaise (OVPF)

Semisopochnoi (United States) | 14 April-20 April 2021 | New Activity / Unrest Cite this Report

Semisopochnoi
Aleutian Ridge Volcanic Arc

AVO reported that an eruption at Semisopochnoi continued during 14-20 April. Sulfur dioxide emissions were identified in satellite images during 13-14 April. An explosion was recorded by the regional infrasound network at 0417 on 14 April, though weather cloud cover as high as 4 km (13,000 ft) a.s.l. prevented satellite confirmation of an ash plume. Ash emissions began during the morning of 15 April and continued through the day, drifting more than 350 km SE at altitudes as high as 6 km (20,000 ft) a.s.l. They did not decrease in intensity, so at 1915 AVO raised the Aviation Color Code to Red and the Volcano Alert Level to Warning. Sustained ash emissions continued on 16 April, though the plume rose as high as 3 km (10,000 ft) a.s.l. and winds pushed it N. Explosions were detected through the night and early in the morning. Minor ash deposits around the volcano were visible. Eruptive activity declined during 16-17 April; one clear satellite view suggested that activity had declined or ceased. At 1249 on 17 April AVO lowered the Aviation Color Code to Orange and the Volcano Alert Level to Watch. Several explosions were recorded during 17-19 April though weather clouds obscured views. Volcanic plumes were visible just above the weather cloud deck (situated at 3 km (10,000 ft) a.s.l.) and drifted S during 19-20 April. A few darker (possibly ash rich) plumes were visible in satellite data at 0700 and 1150 on 19 April and on 20 April.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

Soufriere St. Vincent (Saint Vincent and the Grenadines) | 14 April-20 April 2021 | New Activity / Unrest Cite this Report

Soufriere St. Vincent
Lesser Antilles Volcanic Arc

University of the West Indies Seismic Research Centre (UWI-SRC) and National Emergency Management Organisation (NEMO) reported that the explosive eruption at Soufrière St. Vincent (often simply referred to as “La Soufriere”) continued during 14-20 April, though at a decreasing frequency. Explosions and pyroclastic flows were reported on 13 April, as well as lahars in the Sandy Bay area. During 14 April seismicity continued to be characterized by episodes of tremor, about 13-15 hours apart, separated by swarms of small, long-period (LP) earthquakes. An episode of tremor that began at 1135 was associated with increased explosive activity, though the emissions were gas rich and less energetic than previous events. Another episode of tremor began at 0230 on 15 April along with increased venting. Almost constant swarms of long-period and hybrid events were recorded through the day, punctuated by three brief episodes (less than 30 minutes) of low-level tremor. An episode of tremor began at 2100 and lasted 40 minutes, and was possibly associated with a minor increase in venting. For the first time sulfur dioxide emissions were successfully measured by ground-based instruments; scientists recorded 809 tons per day from a Coast Guard boat along the W coast.

Periods of tremor and near-constant swarms of LP and hybrid events were recorded on 16 April. An explosion at 0615 on 16 April generated an ash plume that rose about 8 km (26,200 ft) a.s.l. and drifted W. A three-minute period of high-level tremor started at the same time and was flowed by over two hours of lower-level tremor. Sulfur dioxide emissions were again measured from the W coast, yielding a flux of 460 tons per day. The rate of LP and hybrid events dropped significantly at 2000. Sulfur dioxide plumes reached India.

Occasional satellite images of the summit showed a series of changes to the new crater, centered in the SW part of the summit crater. By 17 April an Institut de Physique du Globe de Paris scientist reported that the crater was about 900 m N to S, at least 750 m E to W, and about 100 m deep based on RADAR data. Several vents were either visible or inferred from points of emissions. Sulfur dioxide emissions were 232 and 391 tons per day on 17 and 18 April, respectively. A period of high tremor began at 1649 on 18 April. An explosion produced an ash plume that rose to 8 km (26,200 ft) a.s.l. and drifted S and SW. This explosion occurred 52 hours after the last one and was the 30th since the explosive phase started. The period of tremor lasted until about 2100 and was followed by ongoing small LP and hybrid events. The rates of those events dropped again, at around 0100 on 19 April. One rockfall was detected by the seismic network at 0139, and two were noted the next day. At 0400 on 20 April a lahar was detected by the seismic network and lasted for 30 minutes; it possibly traveled down the SE flank.

During 15-19 April NEMO reported details about the people that have evacuated. The total number of displaced people was 12,775 by 19 April, with 6,208 people in 85 public shelters and 6,567 people (1,800 families) in private shelters. There were no casualties caused by the eruption.

Sources: University of the West Indies Seismic Research Centre (UWI-SRC), National Emergency Management Organisation (NEMO), Government of Saint Vincent and the Grenadines, Advanced geospatial Data Management Platform (ADAM)

Aira (Japan) | 14 April-20 April 2021 | Continuing ActivityCite this Report

Aira
Ryukyu Volcanic Arc

JMA reported that during 12-19 April incandescence from Minamidake Crater (at Aira Caldera’s Sakurajima volcano) was visible nightly. There was a total of nine explosions and one eruptive event. Ash plumes rose 1-2 km above the summit and bombs were ejected 800-1,300 m away from the crater. The sulfur dioxide emission rate was high at 2,400 tons per day on 12 April. The Alert Level remained at 3 (on a 5-level scale).

Source: Japan Meteorological Agency (JMA)

Dukono (Indonesia) | 14 April-20 April 2021 | Continuing ActivityCite this Report

Dukono
Halmahera Volcanic Arc

Based on satellite and wind model data, the Darwin VAAC reported that during 13-20 April ash plumes from Dukono rose to 2.1-2.4 km (7,000-8,000 ft) a.s.l. and drifted E and NE. The Alert Level remained at 2 (on a scale of 1-4), and the public was warned to remain outside of the 2-km exclusion zone.

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

Ebeko (Russia) | 14 April-20 April 2021 | Continuing ActivityCite this Report

Ebeko
Kuril Volcanic Arc

Volcanologists in Severo-Kurilsk (Paramushir Island), about 7 km E of Ebeko, observed explosions during 9-16 April that sent ash plumes to 3.6 km (11,800 ft) a.s.l. and drifted in multiple directions. The Aviation Color Code remained at Orange (the second highest level on a four-color scale).

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Kadovar (Papua New Guinea) | 14 April-20 April 2021 | Continuing ActivityCite this Report

Kadovar
Bismarck Volcanic Arc

Based on satellite and wind model data, the Darwin VAAC reported that on 15 April ash plumes from Kadovar rose to an altitude of 1.8 km (6,000 ft) a.s.l. and drifted W.

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Kilauea (United States) | 14 April-20 April 2021 | Continuing ActivityCite this Report

Kilauea
Hawaiian-Emperor Hotspot Volcano Group

HVO reported that the W vent on the inner NW wall of Kilauea's Halema`uma`u Crater continued to supply the lava lake during 14-20 April. Lava flowed at a low rate from the main vent into the lake through crusted-over channels and submerged inlets. The depth of the lake was about 226-227 m and lava continued to circulate in the W part, though the active area continued to shrink; the E half of the lake remained solidified. Lava sometimes overflowed the margins of the lake. The sulfur dioxide emission rate was 950 tons/day on 14 April. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Lewotolok (Indonesia) | 14 April-20 April 2021 | Continuing ActivityCite this Report

Lewotolok
Sunda Volcanic Arc

PVMBG reported that the eruption at Lewotolok continued during 13-19 April. Gray-and-white ash plumes rose as high as 1.5 km above the summit and drifted E and W. Rumbling was often audible. Incandescent material was ejected 300-1,000 m above the summit during 14-16 April. Incandescent material was ejected to the E during 9 and 11-12 April. The Alert Level remained at 3 (on a scale of 1-4) and the public was warned to stay 4 km away from the summit crater.

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

Merapi (Indonesia) | 14 April-20 April 2021 | Continuing ActivityCite this Report

Merapi
Sunda Volcanic Arc

BPPTKG reported that the lava dome just below Merapi’s SW rim and the lava dome in the summit crater both continued to extrude lava during 9-15 April. The SW rim lava-dome volume was an estimated 1,024,800 cubic meters on 15 April, with a growth rate of about 12,200 cubic meters per day, and continued to shed material down the flank. A total of six pyroclastic flows traveled a maximum of 1.8 km down the SW flank. Incandescent avalanches, recorded 119 times, traveled as far as 1.5 km down the SW flank. The volume of the summit lava dome was 1,681,000 cubic meters on 14 April. The Alert Level remained at 3 (on a scale of 1-4), and the public was warned to stay 5 km away from the summit.

Source: Balai Penyelidikan dan Pengembangan Teknologi Kebencanaan Geologi (BPPTKG)

Popocatepetl (Mexico) | 14 April-20 April 2021 | Continuing ActivityCite this Report

Popocatepetl
Trans-Mexican Volcanic Belt

CENAPRED reported that each day during 13-20 April there were 14-34 steam, gas, and ash emissions from Popocatépetl and periods of tremor lasting from 5-15 hours. Two volcanic earthquakes were recorded at 1054 and 2354 on 16 April. Minor crater incandescence was visible overnight during 17-18 April. A M 1.3 volcano-tectonic earthquake was recorded at 2057 on 18 April. The Alert Level remained at Yellow, Phase Two (middle level on a three-color scale).

Source: Centro Nacional de Prevencion de Desastres (CENAPRED)

Raung (Indonesia) | 14 April-20 April 2021 | Continuing ActivityCite this Report

Raung
Sunda Volcanic Arc

PVMBG reported that gray-and-white ash plumes rose 50-400 m above Raung's summit during 13-14 April and drifted N, NE, E, and S. Emissions were white and rose as high as 400 m during 15-16 and 19 April. Weather conditions prented visual observations on some days. The Alert Level remained at 2 (on a scale of 1-4), and the public was warned to remain outside of the 2-km exclusion zone.

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

Sabancaya (Peru) | 14 April-20 April 2021 | Continuing ActivityCite this Report

Sabancaya
Central Andean Volcanic Arc

Instituto Geofísico del Perú (IGP) reported a daily average of 91 explosions at Sabancaya during 12-18 April. Gas-and-ash plumes rose as high as 2.3 km above the summit and drifted S, SW, NW, and N. Eight thermal anomalies originating from the lava dome in the summit crater were identified in satellite data. Minor inflation continued to be detected near Hualca Hualca (4 km N). The Alert Level remained at Orange (the second highest level on a four-color scale) and the public were warned to stay outside of a 12-km radius.

Source: Instituto Geofísico del Perú (IGP)

Sangay (Ecuador) | 14 April-20 April 2021 | Continuing ActivityCite this Report

Sangay
Northern Andean Volcanic Arc

IG reported a high level of activity at Sangay during 13-20 April. Seismicity was characterized by daily explosions, long-period earthquakes, lahar events, and signals indicating emissions. Weather clouds and rain often prevented visual observations of the volcano, though based on the Washington VAAC and webcam images, ash plumes were visible during 13-14 and 17-20 April rising 600-2,400 m above the summit and drifting mainly N, NW, and W. The seismic network occasionally recorded lahar signals, especially during 14-16 April. Ashfall was reported in Chimborazo (W) and Guamote (40 km WNW) on 17 April, and crater incandescence was visible through the night of 19-20 April.

Source: Instituto Geofísico-Escuela Politécnica Nacional (IG-EPN)

Semeru (Indonesia) | 14 April-20 April 2021 | Continuing ActivityCite this Report

Semeru
Sunda Volcanic Arc

PVMBG reported that at 0650 on 19 April an ash plume from Semeru rose 400 m above the summit and drifted W. The Alert Level remained at 2 (on a scale of 1-4), with a general exclusion zone of 1 km and extensions to 5 km in the SSE sector.

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

Sheveluch (Russia) | 14 April-20 April 2021 | Continuing ActivityCite this Report

Sheveluch
Eastern Kamchatka Volcanic Arc

KVERT reported that a thermal anomaly over Sheveluch was identified in satellite images during 9-16 April. The Aviation Color Code remained at Orange (the second highest level on a four-color scale).

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Sinabung (Indonesia) | 14 April-20 April 2021 | Continuing ActivityCite this Report

Sinabung
Sunda Volcanic Arc

PVMBG reported that on 13 April eruptive events at Sinabung generated ash plumes that rose 500-1,600 m above the summit. Avalanches of material traveled 1-1.5 km. On 14 April gray ash plumes rose 500 m above the summit and avalanches traveled 500-700 m down the E and SE flanks. During 15-20 April white plumes were often seen rising as high as 700 m, though weather conditions sometimes prevented visual observations. The Alert Level remained at 3 (on a scale of 1-4), with a general exclusion zone of 3 km and extensions to 5 km in the SE sector and 4 km in the NE sector.

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

Suwanosejima (Japan) | 14 April-20 April 2021 | Continuing ActivityCite this Report

Suwanosejima
Ryukyu Volcanic Arc

JMA reported that incandescence from Suwanosejima's Ontake Crater was visible at night during 9-16 April. Seven explosions generated ash plumes that rose as high as 1.5 km above the crater rim and ejected bombs 400 m away. Ashfall was reported in Toshima village (4 km SSW). The Alert Level remained at 2 and the public was warned to stay 1 km away from the crater.

Source: Japan Meteorological Agency (JMA)

Tanaga (United States) | 14 April-20 April 2021 | Continuing ActivityCite this Report

Tanaga
Aleutian Ridge Volcanic Arc

AVO reported that communication was reestablished with two seismic stations on Tanaga, making a total of four operational stations. On 19 April AVO changed both the Aviation Color Code and the Volcano Alert Level to Green and Normal, respectively, reflecting the resumption of seismically monitoring unrest.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

Ugashik-Peulik (United States) | 14 April-20 April 2021 | Continuing ActivityCite this Report

Ugashik-Peulik
Alaska Peninsula Volcanic Arc

AVO reported a loss of operation and communication with seismic stations that monitor Ugashik-Peulik, likely caused by snow cover. Both the Aviation Color Code and the Volcano Alert Level were changed to Unassigned on 19 April, reflecting the inability to locate earthquakes to detect unrest. Monitoring will continue with the remaining seismic stations, regional infrasound networks, lightning detection, and satellite images.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

Ukinrek Maars (United States) | 14 April-20 April 2021 | Continuing ActivityCite this Report

Ukinrek Maars
Alaska Peninsula Volcanic Arc

AVO reported a loss of operation and communication with seismic stations that monitor Ukinrek-Maars, likely caused by snow cover. Both the Aviation Color Code and the Volcano Alert Level were changed to Unassigned on 19 April, reflecting the inability to locate earthquakes to detect unrest. Monitoring will continue with the remaining seismic stations, regional infrasound networks, lightning detection, and satellite images.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

Weekly Reports Archive

Since the Weekly Volcanic Activity Report began in November 2000, there have been 20,627 individual reports over 1,243 weeks (average of 17 per week) on 338 different volcanoes.

Search by Date

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

Search by Volcano

Puyehue-Cordon Caulle

Dieng Volcanic Complex

Antillanca Volcanic Complex

Atka Volcanic Complex

Etorofu-Yakeyama [Grozny Group]

Fournaise, Piton de la

Moyorodake [Medvezhia]

Krummel-Garbuna-Welcker

Krysuvik-Trolladyngja

Whakaari/White Island

Campi Flegrei del Mar di Sicilia

Palena Volcanic Group

Soufriere St. Vincent

South Sarigan Seamount

Hunga Tonga-Hunga Ha'apai

News Feeds and Google Placemarks

Download Smithsonian / USGS Weekly Volcanic Activity Report Network RSS Feed

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. At the end of each report is a list of the sources used. 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. This feature was first made available on 5 March 2008.

Download Smithsonian / USGS Weekly Volcanic Activity Report Network CAP Feed

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.

Download Smithsonian / USGS Weekly Volcanic Activity Report Network Link

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 profile page and to the complete Weekly Report for that week. This feature was first made available on 1 April 2009.

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 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