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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 18 May-24 May 2016
Name Country Volcanic Province Eruption Start Date Report Status
Etna Italy Sicily Volcanic Province 2022 Nov 27 New
Santa Maria Guatemala Central America Volcanic Arc 1922 Jun 22 New
Turrialba Costa Rica Central America Volcanic Arc New
Aira Japan Ryukyu Volcanic Arc 2017 Mar 25 Continuing
Alaid Russia Kuril Volcanic Arc Continuing
Bagana Papua New Guinea Solomon Volcanic Arc 2000 Feb 28 (in or before) Continuing
Cleveland United States Aleutian Ridge Volcanic Arc Continuing
Colima Mexico Trans-Mexican Volcanic Belt Continuing
Dukono Indonesia Halmahera Volcanic Arc 1933 Aug 13 Continuing
Fuego Guatemala Central America Volcanic Arc 2002 Jan 4 Continuing
Kilauea United States Hawaiian-Emperor Hotspot Volcano Group Continuing
Klyuchevskoy Russia Eastern Kamchatka Volcanic Arc Continuing
Masaya Nicaragua Central America Volcanic Arc 2015 Oct 3 Continuing
Nevado del Ruiz Colombia Northern Andean Volcanic Arc 2014 Nov 18 Continuing
Pavlof United States Aleutian Ridge Volcanic Arc Continuing
Popocatepetl Mexico Trans-Mexican Volcanic Belt 2005 Jan 9 Continuing
Reventador Ecuador Northern Andean Volcanic Arc 2008 Jul 27 Continuing
Sangay Ecuador Northern Andean Volcanic Arc 2019 Mar 26 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
Tengger Caldera Indonesia Sunda Volcanic Arc Continuing
All times are local unless otherwise stated.
Weekly Reports Archive

Since the Weekly Volcanic Activity Report began in November 2000, there have been 20,553 individual reports over 1,240 weeks (average of 17 per week) on 338 different volcanoes.

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

 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 Etna
INGV reported that intense Strombolian activity began at Etna's Northeast Crater (NEC) during the evening of 17 May. Incandescent bombs were ejected above the crater rim and tephra was deposited on the flanks. During the morning of 18 May this activity was accompanied by ash emissions that drifted E and rapidly dispersed. Weak incandescence from the 25 November 2015 vent, on the upper E flank of the New Southeast Crater (NSEC) was visible, and an inclinometer about 1 km NW of NEC recorded rapid inflation of the summit area.

Just after 1250 on 18 May cameras recorded the onset of activity at Voragine (VOR) crater, which within a few minutes evolved into a pulsating lava fountain. At the same time Strombolian activity at NEC diminished and dark ash emissions formed briefly. Ash plumes from VOR rose as high as 3.5 km above the crater and drifted ESE. During the afternoon lava overflowed from the W rim of the Voragine-Bocca Nuova depression, and traveled W within the summit area. A second lava flow, emitted from a vent located at the E base of the Northeast Crater (NEC), expanded into the N portion of the Valle del Bove. The second lava flow remained active until the early morning hours of 19 May. Later that morning, the volcanic tremor amplitude sharply increased, and contemporaneously loud and virtually continuous bangs were heard in populated areas to the E and S of the volcano. A dense eruption plume drifted E at an altitude slightly higher than 1 km above the summit of Etna. Ash and lapilli fell onto the E flank of the volcano, near an area affected by the tephra fall on the previous day. A few hours later images revealed a new lava flow from VOR traveling W. Eruptive activity continued at least through 0900, though the volcanic tremor amplitude had diminished.
Source: Sezione di Catania - Osservatorio Etneo (INGV)
Report for Santa Maria
In a special report posted on 22 May, INSIVUMEH reported a high level of activity at Caliente cone, part of Santa María's Santiaguito lava-dome complex. Strong explosions generated dense ash plumes that rose as high as 2.5 km and drifted over 40 km S, SW, and W. Ashfall was reported in Colomba, Coatepeque, San Felipe Retalhuleu, El Nuevo Palmar, Las Marías, Aldea Loma Linda, San Marcos Palajunoj, the ranches of El Faro, La Florida Patzulin, and El Patrocinio, and other areas on the E flank. Pyroclastic flows traveled 2 km, down the E, S, and W flanks of Caliente cone and down the Cabello de Ángel and San Isidro drainages. The report also noted that during recent days ballistics were ejected as far as 3 km.
Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)
Report for Turrialba
OVSICORI-UNA reported that starting at about 1800 on 17 May the seismic network at Turrialba began recording very-long-period earthquakes, followed by sustained volcanic tremor with significant amplitude that began at 2200. At 1120 on 18 May an ash plume rose 600-700 m above the summit area and drifted SW. At 1430 tremor amplitude decreased, along with the emissions. A gas-and-vapor plume with low ash content rose as high as 300 m and drifted WNW. On 19 May vigorous gas emissions were observed, alternating with ash emissions at 0600, 0938, 1111, and 1405. The plumes rose 300-700 m and drifted S, SW, W, and NW; ashfall was reported in areas of Valle Central, including in Coronado, Guadalupe, and Heredia (38 km W). Tremor increased slightly at 1550 and an ash plume rose 1 km and drifted NNW. On 20 May at 0720 a Strombolian phase began, producing an ash-and-gas plume that rose 3 km and drifted W. The eruptive column collapsed, generating pyroclastic flows that reached the nearby ranches of La Silva and La Picada, Irazu volcano, and the Cráter Central. According to a news article, some airlines have canceled or delayed flights into the Juan Santamaría International Airport (48 km W).

Gas-and-ash emissions continued during 21-22 May; plumes rose as high as 600 m above the summit. Villagers reported ashfall in areas of San José (70 km W), Cartago (25 km SW), Alajuela (49 km W), Heredia (38 km W), Puriscal (65 km WSW), and Jaco (100 km SW). During 22-23 May tremor amplitude decreased. Ash plumes rose as high as 1 km and drifted W and SW on 23 May, causing ashfall in areas downwind including Tapezco (Zarcero-Alfaro Ruíz, 70 km WNW), Guácima de Alajuela (55 km WSW), Cartago (25 km SW), Alajuela, Heredia, Barva (39 km W), Finca Lara (17 km W), Finca Laguna (23 km WNW), Grecia, and Naranjo. Seismic tremor amplitude significantly decreased on 24 May, and ash was no longer visible in the emissions. Gas-and-steam plumes rose 500 m above the volcano.
Sources: Observatorio Vulcanologico y Sismologico de Costa Rica-Universidad Nacional (OVSICORI-UNA), Tico Times
Report for Aira
JMA reported that Aira Caldera’s Sakurajima volcano remained vigorously active. During 16-23 May the seismic network detected 15 explosions at Showa Crater, generating ash plumes that rose as high as 3.5 km above the crater rim (on 16 May). A small-scale explosion occurred at Minamidake summit crater on 18 May. The Alert Level remained at 3 (on a 5-level scale).
Source: Japan Meteorological Agency (JMA)
Report for Alaid
KVERT reported that moderate activity at Alaid continued during 13-20 May. Satellite images showed an intense thermal anomaly over the volcano during 13-16 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 Bagana
Based on analyses of satellite imagery and model data, the Darwin VAAC reported that on 22 May ash plumes from Bagana rose to an altitude of 2.1 km (7,000 ft) a.s.l. and drifted over 110 km W.
Source: Darwin Volcanic Ash Advisory Centre (VAAC)
Report for Cleveland
Based on analysis of satellite data, on 18 May AVO reported that a small-volume lava dome had erupted in Cleveland's summit crater during the past several days. The 50-m-diameter dome was similar in size and morphology to the past 10 domes extruded and destroyed since 2011 (the most recent cycle was earlier in May). Weak seismicity detected on 17 May was likely caused by lava extrusion. The Level of Concern Color Code remained at Orange and the Volcano Alert Level remained at Watch.
Source: US Geological Survey Alaska Volcano Observatory (AVO)
Report for Colima
Based on information from the Mexico City MWO, satellite data, and webcam views, the Washington VAAC reported that on 19 and 24 May ash plumes from Colima rose to altitudes of 4.3-4.9 km (14,000-16,000 ft) a.s.l. and drifted NE.
Source: Washington Volcanic Ash Advisory Center (VAAC)
Report for Dukono
Based on analyses of satellite imagery and wind data, the Darwin VAAC reported that during 18-22 and 24 May ash plumes from Dukono rose to altitudes of 2.1-2.7 km (7,000-9,000 ft) a.s.l. and drifted in multiple directions.
Source: Darwin Volcanic Ash Advisory Centre (VAAC)
Report for Fuego
On 19 May CONRED reported that pyroclastic flows not generated by explosions had descended Fuego's flanks during the previous 12 hours. INSIVUMEH reported that during 19-22 May weak-to-moderate explosions generated ahs plumes that rose 450-750 m above the crater and drifted 7 km W, SW, and S. Incandescent material was ejected 100 m high and generated avalanches down the Las Lajas (SE), Trinidad (S), Santa Teresa (W), Ceniza (SSW), and Honda drainages. A 300-m-long lava flow was active in the Las Lajas drainage. CONRED noted that at 1800 on 22 May Fuego began its 10th Strombolian phase for 2016, characterized by a 1.5-km-long lava flow, explosions, and ash plumes that rose 1.3 km above the crater and drifted 15 km W and SW. During 23-24 May explosions produced ash plumes that rose 4.3-4.8 km and drifted 10-15 km WSW. The lava flow was active as far as 1 km.
Sources: Coordinadora Nacional para la Reducción de Desastres (CONRED), Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)
Report for Kilauea
HVO reported that seismicity beneath Kilauea's summit, upper East Rift Zone, and Southwest Rift Zone was at background levels during 18-24 May. The lava lake continued to circulate and eject spatter in the Overlook vent; some rockfall/wall collapse events occurred during 19-20 May. Webcams recorded glow from multiple spatter cones on the Pu'u 'O'o Crater floor and from skylights in the lava tube on the NE flank of the cone. The June 27th NE-trending lava flow continued to be active within 5.8 km NE of Pu'u 'O'o Crater. On 19 May HVO noted that webcams detected about 1 m of uplift of the Pu'u 'O'o Crater floor during the previous few days. During 19-20 May four small rockfalls from the crater wall resulted in disturbance to the lake surface or increased spattering.
Source: US Geological Survey Hawaiian Volcano Observatory (HVO)
Report for Klyuchevskoy
KVERT reported that a Strombolian eruption at Klyuchevskoy continued during 13-20 May. Satellite and video data showed a lava flow effusing on the SE flank, down the Apakhonchich drainage. Satellite images showed an intense thermal anomaly over the volcano, and ash plumes drifting as far as 80 km E and SE on 13 and 16 May. The Aviation Color Code was raised to Orange.
Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
Report for Masaya
INETER reported that during 18-19 May RSAM values at Masaya fluctuated between 300 and 700 units which are low-to-moderate values. The lava lake in Santiago Crater continued to strongly circulate and the vent widened through 24 May.
Source: Instituto Nicaragüense de Estudios Territoriales (INETER)
Report for Nevado del Ruiz
Servicio Geológico Colombiano’s (SGC) Observatorio Vulcanológico y Sismológico de Manizales reported that during 17-23 May seismicity at Nevado del Ruiz was characterized by long-period and very-long-period earthquakes, episodes of continuous tremor, and pulses of volcanic tremor associated with gas-and-ash emissions. Significant amounts of water vapor and gas rose from the crater during the week. Ashfall was reported in La Florida, Manizales, on 20 May. According to a news article an ash emission on 22 May prompted closure of the La Nubia airport in Manizales. Later that day a gas, steam, and ash plume rose 2.5 km and drifted NW and W. Based on information from SGC, the Washington VAAC reported that on 17 May an ash emission rose to an altitude of 7 km (23,000 ft) a.s.l. Cloud cover in the area prevented satellite observations of the activity. The Alert Level remained at III (Yellow; the second lowest level on a four-color scale).
Sources: Servicio Geológico Colombiano (SGC), Washington Volcanic Ash Advisory Center (VAAC), Salon
Report for Pavlof
On 20 May AVO reported that the period of volcanic activity at Pavlof that began on 13 May had ended; eruptive activity had not been evident in satellite or seismic data since the low-level ash emissions observed on 17 May. AVO lowered the Aviation Color Code to Yellow and Volcano Alert Level to Advisory, and noted that pauses in eruptive activity of days to weeks were common during eruptive episodes at Pavlof.
Source: US Geological Survey Alaska Volcano Observatory (AVO)
Report for Popocatepetl
During 18-24 May there were 43-492 daily emissions from Popocatépetl and as many as eight explosions detected daily; some emissions corresponded with increased crater incandescence at night. Periods of low-amplitude harmonic tremor were also detected almost daily. Daily cloud cover prevented visual observations. The Alert Level remained at Yellow, Phase Two.
Source: Centro Nacional de Prevencion de Desastres (CENAPRED)
Report for Reventador
During 18-24 April IG reported a high level of seismic activity including explosions, volcano-tectonic events, long-period earthquakes, harmonic tremor, and signals indicating emissions at Reventador; cloud cover sometimes prevented visual observations. Incandescent blocks rolled as far as 1.5 km down the flanks on most days. On 18 May a pyroclastic flow traveled 1.5 km down the SE flank, and a gas-and-ash plume rose 1.5 km above the crater. A gas-and-ash plume drifted W on 20 May, and on 24 May a pyroclastic flow traveled 1 km down the SE flank.
Source: Instituto Geofísico-Escuela Politécnica Nacional (IG-EPN)
Report for Sangay
Based on notices from the Guayaquil MWO, the Washington VAAC reported that on 20 May an ash plume from Sangay rose to an altitude of 6.7 km (22,000 ft) a.s.l. and drifted E.
Source: Washington Volcanic Ash Advisory Center (VAAC)
Report for Sheveluch
KVERT reported that during 13-20 May lava-dome extrusion onto Sheveluch’s N flank was accompanied by strong fumarolic activity, dome incandescence, ash explosions, and hot avalanches. Satellite images showed an intense daily thermal anomaly over the dome. The Aviation Color Code remained at Orange.
Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
Report for Sinabung
Based on satellite images and information from PVMBG, the Darwin VAAC reported that during 18, 21-22, and 24 May ash plumes from Sinabung rose to altitudes of 3.6-5.5 km (12,000-18,000 ft) a.s.l. and drifted S and E. BNPB reported that pyroclastic flow descended the flanks at 1648 on 21 May, killing six people and critically injuring three more. The victims were gardening in the village of Gamber, 4 km SE from the summit crater, in the restricted zone. The report noted that activity at Sinabung remained high; four pyroclastic flows descended the flanks on 21 May, and ash plumes rose as high as 3 km.
Sources: Badan Nacional Penanggulangan Bencana (BNPB), Darwin Volcanic Ash Advisory Centre (VAAC)
Report for Suwanosejima
Based on JMA notices, the Tokyo VAAC reported that on 18 May an explosion at Suwanosejima generated an ash plume that rose to an altitude of 1.8 km (6,000 ft) a.s.l. and drifted W.
Source: Tokyo Volcanic Ash Advisory Center (VAAC)
Report for Tengger Caldera
Based on satellite images and wind data, the Darwin VAAC reported that during 23-24 May ash plumes from Tengger Caldera's Bromo cone rose to an altitude of 3 km (10,000 ft) a.s.l. and drifted as far as 75 km NE
Source: Darwin Volcanic Ash Advisory Centre (VAAC)