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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 20 May-26 May 2015
Name Country Volcanic Province Eruption Start Date Report Status
Calbuco Chile Southern Andean Volcanic Arc New
Concepcion Nicaragua Central America Volcanic Arc New
Kilauea United States Hawaiian-Emperor Hotspot Volcano Group New
Piton de la Fournaise France Reunion Hotspot Volcano Group New
Telica Nicaragua Central America Volcanic Arc New
Wolf Ecuador Galapagos Hotspot Volcano Group New
Aira Japan Ryukyu Volcanic Arc 2017 Mar 25 Continuing
Batu Tara Indonesia Sunda 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
Karymsky Russia Eastern Kamchatka Volcanic Arc 2024 Jun 20 Continuing
Kerinci Indonesia Sunda Volcanic Arc Continuing
Krakatau Indonesia Sunda Volcanic Arc Continuing
Kuchinoerabujima Japan Ryukyu Volcanic Arc Continuing
Marapi Indonesia Sunda Volcanic Arc 2023 Dec 3 Continuing
Papandayan Indonesia Sunda Volcanic Arc Continuing
Popocatepetl Mexico Trans-Mexican Volcanic Belt 2005 Jan 9 Continuing
Raung Indonesia Sunda Volcanic Arc Continuing
Reventador Ecuador Northern Andean Volcanic Arc 2008 Jul 27 Continuing
Santa Maria Guatemala Central America Volcanic Arc 1922 Jun 22 Continuing
Sheveluch Russia Eastern Kamchatka Volcanic Arc 1999 Aug 15 Continuing
Shishaldin United States Aleutian Ridge Volcanic Arc Continuing
Sinabung Indonesia Sunda Volcanic Arc Continuing
Slamet Indonesia Sunda Volcanic Arc Continuing
Tengger Caldera Indonesia Sunda Volcanic Arc Continuing
Ubinas Peru Central Andean Volcanic Arc 2024 May 6 Continuing
Villarrica Chile Southern Andean Volcanic Arc 2014 Dec 2 ± 7 days Continuing
Zhupanovsky Russia Eastern Kamchatka 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 20,531 individual reports over 1,239 weeks (average of 17 per week) on 336 different volcanoes.

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


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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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 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 Calbuco
OVDAS-SERNAGEOMIN reported that during 20-26 May activity at Calbuco fluctuated at low levels and continued to decline. Inclement weather prevented observations of the summit area on most days; white plumes were observed rising 300-400 m and drifting SE during 24-26 May, and incandescence at the crater was observed at night during 25-26 May. According to ONEMI, the number of evacuees within the 20-km evacuation zone remained at 6,685 on 26 May. The Alert Level remained at Orange (the second highest level on a four-color scale), and the 10-km-radius exclusion zone continued to be in effect.
Sources: Servicio Nacional de Geología y Minería (SERNAGEOMIN), Oficina Nacional de Emergencia-Ministerio del Interior (ONEMI)
Report for Concepcion
According to a 6 May news article, activity at Concepción had increased about three weeks prior and was characterized by fluctuating levels of seismicity and gas explosions. In a 8 May statement, INETER noted that seismic activity and gas explosions at Concepción had decreased since the day before; 15 gas explosions has been detected in a 24-hour period. By 24 May there had been a total of 987 gas explosions detected by the network since an unspecified date of increased activity.
Sources: Instituto Nicaragüense de Estudios Territoriales (INETER), La Vanguardia
Report for Kilauea
HVO reported that seismicity beneath Kilauea's summit, upper East Rift Zone, and Southwest Rift Zone was at background levels during 20-26 May. The summit tiltmeter network recorded fluctuating inflationary and deflationary tilt from the typical Halema'uma'u source. Nighttime incandescence suggested an active lava pond in an isolated vent W of Pu'u 'O'o Crater. The June 27th NE-trending lava flow continued to be active with surface flows within 8.6 km NE of Pu'u 'O'o.
Source: US Geological Survey Hawaiian Volcano Observatory (HVO)
Report for Piton de la Fournaise
OVPDLF reported that the eruption at Piton de la Fournaise that began on 17 May continued through 26 May. After a peak on 17 May, sulfur dioxide emissions fluctuated but had gradually decreased overall. Lava-flow rates estimated by satellite data had also fluctuated but showed an overall decrease from 24.2 cubic meters per second on 17 May to 2.5 cubic meters per second on 21 May. During 21-22 May observers reported large variations in activity, including increasing heights of the lava fountain (over 50 m high), collapsing parts of the newly formed cinder cone, and a new very fluid lava flow adjacent to the main flow. During an overflight on 23 May scientists observed a large blue sulfur dioxide plume above the vent, lower lava fountains, a smaller vent in the cone, and the presence of a lava tube about 200 m downstream of the vent. During 24-25 May activity remained unchanged; low lava fountains and low-level lava flows persisted.
Source: Observatoire Volcanologique du Piton de la Fournaise (OVPF)
Report for Telica
On 8 May INETER reported that activity at Telica had been increasing. Earthquakes SE of the volcano and seven small-intensity explosions had been detected during an unspecified period, although a M 2.4 earthquake had occurred at 1102 on 7 May. During 11-12 May there were 18 explosions, for a total of 64 since the increased activity began. An explosion at 0950 on 12 May was accompanied by small quantities of ash emissions. At 1223 an explosion generated a gas-and-ash plume and ejected hot rocks (pre-existing material) 400 m high and to the W. Minor ashfall was reported in El Realejo, Corinth, Posoltega, and Chichigalpa. Seismicity was at normal levels. By 1200 on 18 May a total of 421 small explosions had been detected (164 in the previous 24 hours); gas emissions were low. During 18-20 May reports noted that 31 small gas explosions had been detected; ash had not been detected since 17 May and activity was decreasing. During 21-22 May 16 small gas explosions occurred, for a total of 540 explosions. Gas explosions continued during 22-24 May. A few of the explosions ejected hot rock fragments and generated ash plumes. Ashfall was reported in Posoltega, Guanacastal, Quezalguaque, Chinandega, El Viejo, Chichigalpa, and El Realejo.
Source: Instituto Nicaragüense de Estudios Territoriales (INETER)
Report for Wolf
According to IG the seismic station located on Fernandina Island recorded several events at Wolf (on Isabela Island) starting at 2350 on 24 May. The most significant signal occurred at 0058 on 25 May, corresponding to an explosion and the start of an eruption. At 0215 the Washington VAAC detected an ash plume that rose to an altitude of 10.7 km (35,000 ft) a.s.l. and drifted 65 km SW. At 0345 one ash plume drifted 250 km ENE at an altitude of 15.2 km (50,000 ft) a.s.l., and another drifted 250 km S at an altitude of 13.7 km (45,000 ft) a.s.l. Starting at 0428 the Hawai'i Institute of Geophysics and Planetology (HIGP) reported intense thermal anomalies on Wolf's SE flank based on MODIS satellite data. Galapagos National Park staff reported an arcuate fissure along the upper SSE rim and several lava flows descending the flanks. Later that day the VAAC noted a smaller ash emission that drifted 150 km SW, and a bright thermal anomaly that had persisted. Satellites detecting sulfur dioxide showed that the cloud was sulfur-dioxide rich and ash poor; ~100-200 kt of sulfur dioxide had been emitted during the first 13 hours of the eruption.
Sources: Instituto Geofísico-Escuela Politécnica Nacional (IG-EPN), Washington Volcanic Ash Advisory Center (VAAC), Galapagos Conservancy, Simon Carn, Hawai'i Institute of Geophysics and Planetology (HIGP) Thermal Alerts Team
Report for Aira
JMA reported 19 explosions during 18-25 May from Showa Crater at Aira Caldera’s Sakurajima volcano, some that ejected tephra as far as 1,300 m, and incandescence from the crater was occasionally visible at night. During 21-22 May explosions generated ash plumes that rose 3-4.3 km above the crater. The Alert Level remained at 3 (on a 5-level scale).
Source: Japan Meteorological Agency (JMA)
Report for Batu Tara
Based on analyses of satellite imagery and wind data, the Darwin VAAC reported that during 21-22 May ash plumes from Batu Tara rose to an altitude of 2.5 km (8,000 ft) a.s.l. and drifted over 80 km W.
Source: Darwin Volcanic Ash Advisory Centre (VAAC)
Report for Colima
Based on satellite images, the Washington VAAC reported that on 21 May an ash plume rose from Colima to an altitude below 4.9 km (16,000 ft) a.s.l. and drifted W.
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 17-19 May ash plumes from Dukono rose to an altitude of 3 km (10,000 ft) a.s.l. and drifted 75 km NW.
Source: Darwin Volcanic Ash Advisory Centre (VAAC)
Report for Fuego
INSIVUMEH reported that activity at Fuego remained high during 21-26 May. Explosions produced ash plumes that rose 800 m above the crater and drifted 8-10 km W and SW. Ash fell in nearby areas including Panimache I and II, Morelia, and Santa Sofía. Homes within a 10-km radius vibrated from explosions. Incandescent material was ejected 150-200 m above the crater and incandescent block avalanches descended the Cenizas (SSW) and Trinidad (S) ravines.
Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)
Report for Karymsky
KVERT reported that moderate activity at Karymsky likely continued during 15-22 May. Satellite images detected a thermal anomaly during 15-16 May and an ash plume drifting 27 km W on 16 May. The Aviation Color Code remained at Orange.
Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
Report for Kerinci
PVMBG reported that during 1 February-21 May 2015 white plumes from Kerinci rose 50-150 m and drifted E and W. Seismicity during 1-21 May was dominated by signals indicating emissions (100-110 per day on average) as well as volcanic earthquakes (1 per day on average). The Alert Level remained at 2 (on a scale of 1-4). Residents and visitors were advised not to enter an area within 3 km of the summit.
Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)
Report for Krakatau
PVMBG reported that during 22 April-25 May diffuse white plumes rose 25 m above Anak Krakatau, although foggy weather often prevented observations. Seismicity was high during May, and continued to be dominated by shallow and deep volcanic earthquakes, and signals indicating emissions. The Alert Level remained at 2 (on a scale of 1-4). Residents and visitors were warned not to approach the volcano within 1 km of the crater.
Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)
Report for Kuchinoerabujima
JMA reported that no eruptions occurred from Kuchinoerabujima during 18-22 May, although the level of activity remained elevated. White plumes rose 600 m above Shindake Crater, and incandescence from the W part of the crater was observed at night. Volcanic earthquakes were detected; tremor was absent. Fumarolic activity in a crack in W part of the crater was observed during a field survey. The Alert Level remained at 3 (on a scale of 1-5).
Source: Japan Meteorological Agency (JMA)
Report for Marapi
PVMBG reported that during February-25 May diffuse white plumes rose as high as 300 m above Marapi, although inclement weather often prevented observations. Seismicity fluctuated. The Alert Level remained at 2 (on a scale of 1-4). Residents and visitors were advised not to enter an area within 3 km of the summit.
Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)
Report for Papandayan
PVMBG reported that during 22 April-25 May seismicity at Papandayan was dominated by shallow volcanic earthquakes but also consisted of volcanic earthquakes, low-frequency earthquakes, tremor, and local and remote tectonic earthquakes. Visual monitoring occurred from the Pakuwon Village post; observers noted white plumes rising at most 30 m above the crater. The Alert Level remained at 2 (on a scale of 1-4); residents and tourists were reminded not to approach the craters within a 1-km radius.
Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)
Report for Popocatepetl
CENAPRED reported that during 20-26 May the seismic network at Popocatépetl recorded 40-307 daily emissions consisting of water vapor, gas, and sometimes ash; cloud cover often prevented visual observations. Nighttime crater incandescence was noted every night; sometimes the incandescence would become more intense with accompanying emissions. A small explosion at 0023 on 21 May generated a plume with low ash content that rose 800 m and drifted SW. During 22-24 May ash plumes rose 0.5-2.5 km and drifted SW. Ashfall was reported in Ocuituco (24 km SW) on 22 May. From 1702 to 1955 on 25 May a series of explosions accompanied by tremor ejected steam, gas, and ash plumes that drifted SSE. Explosions were detected on 26 May; ashfall was rpeorted in Tetela del Volcán (20 km SW).The Alert Level remained at Yellow, Phase Two.
Source: Centro Nacional de Prevencion de Desastres (CENAPRED)
Report for Raung
PVMBG reported that, during infrequent times of clear weather during 1 February-21 May, gray and gray-to-brown plumes were observed rising as high as 300 m above Raung's crater rim. Rumbling was frequently heard at the observation post. Crater incandescence was observed during February and on 12 April. Seismicity fluctuated and was dominated by tremor. The Alert Level remained at 2 (on a scale of 1-4); residents and tourists were reminded not to approach the craters within a 2-km radius.
Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)
Report for Reventador
During 20-26 May IG reported moderate-to-high seismic activity including explosions, long-period earthquakes, harmonic tremor, and signals indicating emissions at Reventador; cloud cover sometimes prevented visual observations. A lava flow on the SW flank advanced during 20-21 May. During 24-25 May ash plumes rose 600-800 m and drifted SW, although at 1730 on 25 May a water vapor plume with moderate ash content rose 1.5 km and drifted SW.
Source: Instituto Geofísico-Escuela Politécnica Nacional (IG-EPN)
Report for Santa Maria
INSIVUMEH reported that a moderate explosion at Caliente cone, part of Santa María's Santiaguito lava-dome complex, generated an ash plume that rose 600 m and drifted SW; ashfall was reported in La Florida and Monte Claro. During 23-24 May explosions produced ash plumes that rose 500 m and drifted SE and E. Ash fell in the Palajunoj area and Monte Claro. Small explosions and avalanches were detected during 24-26 May.
Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)
Report for Sheveluch
KVERT reported that during 15-22 May lava-dome extrusion onto Sheveluch’s N flank was accompanied by fumarolic activity. A thermal anomaly was detected in satellite images during 15-19 May. The Aviation Color Code remained at Orange.
Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
Report for Shishaldin
AVO reported that seismicity at Shishaldin continued to be elevated over background levels 20-26 May indicating that low-level eruptive activity confined to the summit crater likely continued. Elevated surface temperatures were periodically detected in satellite images. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.
Source: US Geological Survey Alaska Volcano Observatory (AVO)
Report for Sinabung
PVMBG reported that foggy weather often prevented visual observations of Sinabung during 19-25 May, except for a few clearer periods on some days. White plumes rose as high as 800 m during 19-20 and 22-24 May. Lava from the lava dome was active as far as 1.5 km S during 21-23 May. On 24 May a pyroclastic flow traveled 2 km down the S flank and produced an ash plume that rose 500 m. Seismicity consisted of avalanche signals, low-frequency and hybrid events, tectonic events, and volcanic earthquakes; RSAM values increased due to an increase of avalanche signals. The Alert Level remained at 3 (on a scale of 1-4). Visitors and tourists were prohibited from approaching the crater within a radius of 6 km on the S, 5 km on the SE flanks, and 3 km in the other directions.
Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)
Report for Slamet
PVMBG reported that during 21 April-21 May dense white plumes rose as high as 700 m above Slamet's crater. Seismicity consisted of emission signals and tremor; RSAM values fluctuated. The Alert Level remained at 2 (on a scale of 1-4). Residents and tourists were warned to not approach the crater within a radius of 2 km.
Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)
Report for Tengger Caldera
PVMBG reported that during 1 April-25 May white plumes from Tengger Caldera's Bromo cone rose 50 m above the crater. A sulfur dioxide odor was noted at the Bromo observation post. Seismicity was dominated by tremor, but also included volcanic earthquakes. The Alert Level remained at 2 (on a scale of 1-4). Residents and visitors were warned not to approach the crater within a radius of 1 km.
Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)
Report for Ubinas
Instituto Geofísico del Perú (IGP) Observatorio Volcanológico del Sur (OVS) reported that during 19-26 May long-period earthquakes continued at the same rate while volcano-tectonic and hybrid events increased. Overall the dominant signal was spasmodic tremor associated with ash-and-steam emissions. While conducting fieldwork during 19-22 May, OVS staff observed persistent water vapor, gas, and ash emissions that rose 400 m. At 1051 and 1213 on 24 May ash plumes rose as high as 1.2 km and drifted NE and E.
Source: Instituto Geofísico del Perú (IGP)
Report for Villarrica
OVDAS-SERNAGEOMIN reported no significant changes at Villarrica during 20-26 May. Seismicity had significantly decreased, although the data continued to indicate small explosions and degassing from the lava lake. Deformation data suggested inflation during 24-26 May. The Alert Level remained at Orange (the second highest level on a four-color scale) and the public was warned to stay outside of a 5-km radius around the crater and away from drainages.
Sources: Servicio Nacional de Geología y Minería (SERNAGEOMIN), Oficina Nacional de Emergencia-Ministerio del Interior (ONEMI)
Report for Zhupanovsky
On 16 May KVERT reported that the explosive eruption that began at Zhupanovsky on 6 June 2014 ended at the beginning of April 2015. The last ash plume occurred on 3 April, although weak thermal anomalies continued to be detected. The Aviation Color Code was lowered to Yellow. On 20 May an ash plume drifted 470 km E.
Source: Kamchatkan Volcanic Eruption Response Team (KVERT)