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Smithsonian / USGS Weekly Volcanic Activity Report

Weekly Volcanic Activity Map

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 12 May-18 May 2021
Name Location Eruption Start Date Report Status
Great Sitkin Andreanof Islands (USA) New
Sheveluch Central Kamchatka (Russia) 1999 Aug 15 New
Stromboli Aeolian Islands (Italy) 1934 Feb 2 New
Aira Kyushu (Japan) 2017 Mar 25 Continuing
Dukono Halmahera (Indonesia) 1933 Aug 13 Continuing
Ebeko Paramushir Island (Russia) 2016 Oct 20 Continuing
Ibu Halmahera (Indonesia) 2008 Apr 5 Continuing
Karymsky Eastern Kamchatka (Russia) 2021 Apr 3 Continuing
Kilauea Hawaiian Islands (USA) Continuing
Krysuvik-Trolladyngja Iceland 2021 Mar 19 Continuing
Langila New Britain (Papua New Guinea) 2015 Oct 22 (?) Continuing
Lewotolok Lembata Island (Indonesia) 2020 Nov 27 Continuing
Merapi Central Java (Indonesia) 2020 Dec 31 Continuing
Pacaya Guatemala 2015 Jun 7 ± 1 days Continuing
Piton de la Fournaise Reunion Island (France) Continuing
Sabancaya Peru 2016 Nov 6 Continuing
Sangay Ecuador 2019 Mar 26 Continuing
Santa Maria Guatemala 1922 Jun 22 Continuing
Semeru Eastern Java (Indonesia) 2014 Apr 1 ± 15 days Continuing
Semisopochnoi Aleutian Islands (USA) Continuing
Sinabung Indonesia 2020 Aug 8 Continuing
Suwanosejima Ryukyu Islands (Japan) 2004 Oct 23 Continuing
Taal Luzon (Philippines) Continuing
Tengger Caldera Eastern Java (Indonesia) Continuing
Ugashik-Peulik United States Continuing
Ukinrek Maars United States Continuing
Veniaminof United States Continuing
Weekly Reports Archive

Since the Weekly Volcanic Activity Report began in November 2000, there have been 16,863 individual reports over 1,073 weeks (average of 16 per week) on 311 different volcanoes.

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Agung Copahue Ijen Little Sitkin Pelee South Sarigan Seamount
Ahyi Cotopaxi Iliamna Llaima Peuet Sague Spurr
Aira Cuicocha Iliwerung Loihi Pinatubo St. Helens
Akan Cumbal Inielika Lokon-Empung Planchon-Peteroa Stromboli
Alaid Dabbahu Ioto Lopevi Poas Sulu Range
Alu-Dalafilla Dempo Irazu Machin Popocatepetl Sumbing
Ambae Descabezado Grande Iya Makian Puyehue-Cordon Caulle Sundoro
Ambang Dieng Volcanic Complex Izu-Torishima Makushin Rabaul Suretamatai
Ambrym Dukono Jackson Segment Maly Semyachik Raikoke Suwanosejima
Anatahan Ebeko Kaba Manam Ranakah Taal
Antillanca Volcanic Complex Ebulobo Kadovar Manda Hararo Raoul Island Tair, Jebel at
Antuco Egon Kambalny Marapi Rasshua Takawangha
Apoyeque Ekarma Kanaga Maroa Raung Talang
Arenal Epi Kanlaon Martin Redoubt Tambora
Asamayama Erebus Karangetang Masaya Reventador Tanaga
Askja Erta Ale Karkar Maule, Laguna del Reykjanes Tandikat-Singgalang
Asosan Etna Karthala Mauna Loa Rincon de la Vieja Tangkoko-Duasudara
Augustine Etorofu-Yakeyama [Grozny Group] Karymsky Mayon Rinjani Tangkuban Parahu
Avachinsky Eyjafjallajokull Kasatochi McDonald Islands Ritter Island Tara, Batu
Awu Fernandina Katla Melimoyu Rotorua Telica
Axial Seamount Fogo Katmai Merapi Ruang Tenerife
Azul, Cerro Fonualei Kavachi Midagahara Ruapehu Tengger Caldera
Azumayama Fournaise, Piton de la Kelimutu Misti, El Ruiz, Nevado del Three Sisters
Bagana Fourpeaked Kelut Miyakejima Sabancaya Tinakula
Balbi Fuego Kerinci Momotombo Sakar Tofua
Bamus Fujisan Ketoi Monowai Salak Tokachidake
Banda Api Fukutoku-Oka-no-Ba Kharimkotan Montagu Island San Cristobal Tolbachik
Bardarbunga Galeras Kick 'em Jenny Moyorodake [Medvezhia] San Miguel Toliman
Barren Island Galunggung Kikai Mutnovsky San Vicente Tongariro
Batur Gamalama Kilauea Myojinsho Sangay Tungurahua
Bezymianny Gamkonora Kirishimayama Nabro Sangeang Api Turrialba
Bogoslof Gareloi Kizimen Negra, Sierra Santa Ana Ubinas
Brava Gaua Klyuchevskoy Negro, Cerro Santa Maria Ugashik-Peulik
Bristol Island Gorely Kolokol Group Nightingale Island Sarigan Ukinrek Maars
Bulusan Great Sitkin Korovin Nishinoshima Sarychev Peak Ulawun
Calbuco Grimsvotn Koryaksky Nisyros Saunders Unnamed
Callaqui Guagua Pichincha Krakatau Novarupta Semeru Unnamed
Cameroon Guallatiri Krummel-Garbuna-Welcker NW Rota-1 Semisopochnoi Veniaminof
Campi Flegrei del Mar di Sicilia Guntur Krysuvik-Trolladyngja Nyamulagira Seulawah Agam Villarrica
Cayambe Hachijojima Kuchinoerabujima Nyiragongo Sheveluch West Mata
Cereme Hakoneyama Kurikomayama Okataina Shishaldin Westdahl
Chachadake [Tiatia] Heard Kusatsu-Shiranesan Okmok Simbo Whakaari/White Island
Chaiten Hekla Kverkfjoll Ontakesan Sinabung Witori
Chiginagak Helgrindur Lamington Oraefajokull Sinarka Wolf
Chikurachki Hierro Lamongan Osorno Siple Yasur
Chiles-Cerro Negro Hokkaido-Komagatake Langila Pacaya Sirung Zaozan [Zaosan]
Chillan, Nevados de Home Reef Lanin Pagan Slamet Zavodovski
Chirinkotan Hood Lascar Palena Volcanic Group Snaefellsjokull Zhupanovsky
Chirpoi Huaynaputina Lateiki Paluweh Soputan Zubair Group
Cleveland Hudson, Cerro Lengai, Ol Doinyo Panarea Sorikmarapi
Colima Huila, Nevado del Leroboleng Papandayan Sotara
Colo Hunga Tonga-Hunga Ha'apai Lewotobi Parker Soufriere Hills
Concepcion Ibu Lewotolok Pavlof Soufriere St. Vincent
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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.



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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 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.

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)

Report for Great Sitkin
AVO reported that elevated surface temperatures at Great Sitkin had been identified in satellite images since January and had been increasing in frequency during the previous two months. A minor increase in seismicity began to be recorded on 9 May and volcanic gas emissions increased on 10 May. AVO raised the Aviation Color Code to Yellow and the Volcano Alert Level to Advisory on 12 May.
Source: US Geological Survey Alaska Volcano Observatory (AVO)
Report for Sheveluch
KVERT reported that a thermal anomaly over Sheveluch was identified in satellite images during 7-14 May. A new lava block (named “Dolphin-2”) that extruded from the top of the lava dome was visible in a 15 May photo. The Aviation Color Code remained at Orange (the second highest level on a four-color scale).
Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
Report for Stromboli
INGV reported a collapse event at Stromboli’s Area N (North Crater area) on 19 May. A series of explosions began at 1447, producing a pyroclastic flow that at 1451 descended the Sciara del Fuoco to the coast and traveled 1 km over the sea. The explosions and pyroclastic flow produced large, dense ash clouds that rose above both the summit area and along the entire length of the pyroclastic flow. A series of less intense pyroclastic flows began at 1502 that also reached the sea. Lava flows from Area N also descended the Sciara del Fuoco to the coast.
Source: Sezione di Catania - Osservatorio Etneo (INGV)
Report for Aira
JMA reported that during 10-17 May nightly incandescence from Minamidake Crater (at Aira Caldera’s Sakurajima volcano) was visible. Very small eruptive events were occasionally recorded. The Alert Level remained at 3 (on a 5-level scale), and residents were warned to stay 2 km away from the crater.
Source: Japan Meteorological Agency (JMA)
Report for Dukono
Based on satellite and wind model data, the Darwin VAAC reported that during 11-17 May ash plumes from Dukono rose to 2.1-2.4 km (7,000-8,000 ft) a.s.l. and drifted in multiple directions. 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)
Report for Ebeko
Volcanologists in Severo-Kurilsk (Paramushir Island), about 7 km E of Ebeko, observed explosions during 6, 9, and 12-13 May that sent ash plumes to 3.5 km (11,500 ft) a.s.l. and drifted N, NE, E, and SE. The Aviation Color Code remained at Orange (the second highest level on a four-color scale).
Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
Report for Ibu
PVMBG reported that during 11-12 and 15-17 gray-and-white ash plumes from Ibu rose 200-800 m above the summit and drifted mainly N, W, and S. Inclement weather sometimes prevented visual observations, especially during 13-14 May. The Alert Level remained at 2 (on a scale of 1-4), and the public was warned to stay at least 2 km away from the active crater and 3.5 km away on the N side.
Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)
Report for Karymsky
KVERT reported that a weak thermal anomaly over Karymsky was visible in satellite images on 7 and 9 May; weather clouds prevented observations during 8-14 May. The Aviation Color Code remained at Orange (the second highest level on a four-color scale).
Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
Report for Kilauea
HVO reported that the W vent on the inner NW wall of Kilauea's Halema`uma`u Crater continued to supply the 229-m-deep lava lake at a low rate through a submerged inlet during 12-18 May. Lava circulated in two small pools in the W part. The solidified portion comprised 99 percent of the total area, based on thermal measurements acquired on 13 May. The sulfur dioxide emission rate was 115-225 tons per day during 12-14 May, continuing a downward trend that began in mid-April. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.
Source: US Geological Survey Hawaiian Volcano Observatory (HVO)
Report for Krysuvik-Trolladyngja
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 11-18 May. The lava effusion rate was 10.8 meters per second, lower than the 12.9 meters per second rate recorded the week before. Pulsating lava fountains from crater 5, about 7-8 episodes per hour, sent material higher than 300 m. Very high fountains were visible in Reykjavik. Lava continued to flow into the Meradalir Valley; on 17 May video showed sections of the cone’s rim collapsing into the crater. By 18 May the area of the flow field had grown to 2.06 square kilometers, the total volume erupted was 38 million cubic meters. Authorities directed the construction of earthen barriers to prevent lava flowing into the Nátthaga valley and possibly overtaking Highway 427 (Suðurstrandarvegur) to the S, protecting the road and buried fiberoptic cables. The Aviation Color Code remained at Orange due to the lack of ash and tephra emissions. Authorities warned of increased gas emissions hazards.
Sources: Icelandic Meteorological Office (IMO), Institute of Earth Sciences, Icelandic National Broadcasting Service (RUV), National Commissioner of the Icelandic Police (NCIP) Department of Civil Protection and Emergency Management
Report for Langila
Based on analyses of satellite imagery and wind model data, the Darwin VAAC reported that on 15 May ash plumes from Langila rose as high as 3 km (5,000 ft) a.s.l. A lower portion of the cloud at 2.4 km (8,000 ft) a.s.l. drifted NW at the upper portion drifted S. On 16 May an ash plume rose to 2.1 km
Source: Darwin Volcanic Ash Advisory Centre (VAAC)
Report for Lewotolok
PVMBG reported that white-and-gray plumes from Lewotolok rose as high as 600 m and drifted W and NW during 12-17 May. Incandescent material was ejected 100-300 m above the summit during 14-16 May and 300 m SE on 15 May. Rumbling and thumping sounds were heard during 14-17 May. The Alert Level remained at 3 (on a scale of 1-4) and the public was warned to stay 3 km away from the summit crater.
Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)
Report for Merapi
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 7-13 May. The SW rim lava-dome volume was an estimated 1.16 million cubic meters on 2 May, with a growth rate of about 11,500 cubic meters per day, and continued to shed material down the flank. A total of four pyroclastic flows traveled a maximum of 1.5 km down the SW flank. Incandescent avalanches, recorded 49 times, traveled as far as 1.8 km down the SW flank and twice went 700 m SE. The summit lava dome grew 2 m taller during 6-16 May. Electronic Distance Measurement (EDM) data showed a distance shortening between points in the NW at a rate of 0.7 cm per day, indicating minor inflation. 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)
Report for Pacaya
INSIVUMEH reported that during 12-18 May the cone on Pacaya’s N flank (near Cerro Chino) continued to be active, feeding lava flows and occasionally ejecting incandescent material as high as 40 m. The lava flow slowly advanced mainly W, though remained about 2.4 km long. The flow also spread laterally and shed incandescent blocks, especially along the flow margins and where the flow travels down steep slopes. Gas-and-ash plumes visible almost daily rose as high as 900 m above the summit and drifted W, SW, and S. Ashfall was reported in El Rodeo (4 km WSW) during 15-16 May and in El Patrocinio (about 5 km W) during 15-17 May.
Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)
Report for Piton de la Fournaise
OVPF reported that the eruption at Piton de la Fournaise continued during 12-18 May at both craters, though at low levels. Lava flows mainly traveled though lava tubes and emerged from the end of the flow field, advancing E to 920 m elevation by 13 May. Minor inflation of the summit area was recorded. Dense gas plumes rose from both craters. The Alert Level remained at 2-2.
Source: Observatoire Volcanologique du Piton de la Fournaise (OVPF)
Report for Sabancaya
Instituto Geofísico del Perú (IGP) reported a daily average of 37 explosions at Sabancaya during 10-16 May. Gas-and-ash plumes rose as high as 3.5 km above the summit and drifted S, SE, E, and NE. Ashfall was reported in the district of Chivay (NE), in the area of Achacota. 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)
Report for Sangay
IG reported a high level of activity at Sangay during 12-18 May. Weather clouds and rain often prevented visual and webcam observations of the volcano; daily lahars were detected by the seismic network. Ash plumes rose 900-1,200 m and drifted W during 14-15 May. Several dense ash emissions were identified in satellite images on 16 May. According to the Washington VAAC ash plumes rose as high as 12.2 km (40,000 ft) a.s.l. and drifted N; part of the ash plume drifted WSW at 6.4 km (21,000 ft) a.s.l. Minor ashfall was reported in the local community of Ishupamba (Province of Chimborazo), near the volcano. Ash plumes rose 1.2-1.5 km above the volcano and drifted WSW and SW during 17-18 May.
Source: Instituto Geofísico-Escuela Politécnica Nacional (IG)
Report for Santa Maria
INSIVUMEH reported that on 15 May lahars descended Santa María's Cabello de Ángel (a tributary of Nimá I) drainage, carrying tree trunks, branches, and blocks 1-3 m in diameter. The lahars reached the El Faro estate. The next day lahars descended the Cabello de Ángel and Nimá I drainages carrying blocks up to 1 m in diameter. The lahars were 25 m wide and 1 m deep, and had a sulfur odor.
Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)
Report for Semeru
PVMBG reported that Semeru continued to erupt during 12-18 May. Dense gray-and-white plumes rose 300-700 m above the summit and drifted SW and N during 13-15 and 17 May. Avalanches of material traveled as far as 200 m down the Kobokan drainage on 13 May. 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)
Report for Semisopochnoi
AVO reported that weakly elevated surface temperatures and sulfur dioxide gas emissions at Semisopochnoi were identified in satellite images during 16-17 May. Several small explosions were recorded in infrasound data during 17-18 May; a small ash cloud was observed in a satellite image from 1521. Sulfur dioxide gas emissions and steaming from the active vents were identified in satellite data. The Aviation Color Code was raised to Orange and the Volcano Alert Level was raised to Watch on 18 May.
Source: US Geological Survey Alaska Volcano Observatory (AVO)
Report for Sinabung
PVMBG reported that the eruption at Sinabung continued during 12-18 May. Weather conditions often prevented visual observations of the volcano; white fumarolic plumes were visible on 11, 13, and 15 May rising as high as 700 m above the summit and drifting in multiple directions. On 11 May an eruptive event produced a gray ash plume that rose up to 1 km. Avalanches of material traveled 1 km down the E and SE flanks on 12 May. On 13 May gray ash plumes rose 700-1,000 m above the summit, pyroclastic flows traveled 2.5 km down the E and SE flanks, and avalanches moved down the E and SE flanks as far as 1 km. On 14 May pyroclastic flows traveled as far as 4 km SE. 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)
Report for Suwanosejima
JMA reported that six explosions at Suwanosejima's Ontake Crater produced eruption plumes that rose as high as 2 km above the crater rim during 7-14 May. Large volcanic bombs were ejected 400 m from the crater. The Alert Level remained at 2 and the public was warned to stay 1 km away from the crater.
Source: Japan Meteorological Agency (JMA)
Report for Taal
PHIVOLCS reported that unrest at Taal continued during 11-18 May. Low-level background tremor that had begun at 0905 on 8 April continued, along with 0-201 daily low-frequency events, 2-355 daily volcanic earthquakes, and 0-249 periods of volcanic tremor with variable durations (1-35 minutes); seismicity was the lowest during 13-14 May. Most of the earthquakes were very shallow (less than 5 km deep) beneath Taal Volcano Island (TVI) and the NE part of Taal Lake. Upwelling of hot volcanic fluids in the crater lake during most days was accompanied by steam plumes that were as tall as 300 m. On other days fumarolic plumes from vents in Main Crater rose 5-40 m. Almost-daily measurements of sulfur dioxide emissions were 2,214-3,758 tonnes/day, though a peak of 5,179 tonnes/day was recorded on 12 May and comparable to a 13 January 2020 measurement taken when the volcano was erupting. Tilt data showed a minor but abrupt inflation signal on 17 May; slow and steady inflation of the Taal region was recorded by multiple instruments after the January 2020 eruption. On 18 May PHIVOLCS noted the continuing state of elevated unrest, reminding the public that the Alert Level for Taal remained at 2 (on a scale of 0-5). PHIVOLCS strongly recommended no entry onto the island, and access to the Main Crater, Daang Kastila fissure (along the walking trail), and boating on Taal Lake was strictly prohibited.
Source: Philippine Institute of Volcanology and Seismology (PHIVOLCS)
Report for Tengger Caldera
PVMBG reported that during 14-17 May white-and-gray plumes rose as high as 500 m above the summit of Tengger Caldera’s Bromo cone and drifted in multiple directions. A sulfur odor was noted at the observation post. The Alert Level remained at 2 (on a scale of 1-4), and visitors were warned to stay outside of a 1-km radius of the crater.
Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)
Report for Ugashik-Peulik
On 12 May AVO changed the Aviation Color Code and Volcano Alert Level for Ugashik-Peulik to Green and Normal, respectively, reflecting that communication with seismic stations had been re-established, allowing for the location of earthquakes and detection of unrest.
Source: US Geological Survey Alaska Volcano Observatory (AVO)
Report for Ukinrek Maars
On 12 May AVO changed the Aviation Color Code and Volcano Alert Level for Ukinrek-Maars to Green and Normal, respectively, reflecting that communication with seismic stations had been re-established, allowing for the location of earthquakes and detection of unrest.
Source: US Geological Survey Alaska Volcano Observatory (AVO)
Report for Veniaminof
No eruptive activity at Veniaminof had been recorded in seismic or infrasound data since early April. On 12 May AVO changed both the Aviation Color Code and Volcano Alert Level to Unassigned, noting that several seismic station outages impeded the ability to detect seismic unrest at the volcano. Monitoring was ongoing based on the utilization of the remaining seismic stations, the regional infrasound networks, the detection of lightning, and satellite image monitoring.
Source: US Geological Survey Alaska Volcano Observatory (AVO)