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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 29 May-4 June 2013
Name Location Eruption Start Date Report Status
Cleveland Chuginadak Island (USA) New
Copahue Central Chile-Argentina New
Kikai Ryukyu Islands (Japan) 2023 Mar 27 New
Mayon Luzon (Philippines) 2023 Apr 27 ± 2 days New
Pavlof Alaska Peninsula, Alaska New
Popocatepetl Mexico 2005 Jan 9 New
Turrialba Costa Rica New
Aira Kyushu (Japan) 2017 Mar 25 Continuing
Bagana Bougainville (Papua New Guinea) 2000 Feb 28 (in or before) Continuing
Fuego South-Central Guatemala 2002 Jan 4 Continuing
Karymsky Eastern Kamchatka (Russia) Continuing
Kilauea Hawaiian Islands (USA) Continuing
Kizimen Eastern Kamchatka (Russia) Continuing
Pacaya South-Central Guatemala Continuing
Poas Costa Rica 2023 Dec 1 Continuing
Rabaul New Britain (Papua New Guinea) Continuing
Reventador Ecuador 2008 Jul 27 Continuing
Santa Maria Southwestern Guatemala 1922 Jun 22 Continuing
Sheveluch Central Kamchatka (Russia) 1999 Aug 15 Continuing
Tolbachik Central Kamchatka (Russia) Continuing
All times are local unless otherwise stated.
Weekly Reports Archive

Since the Weekly Volcanic Activity Report began in November 2000, there have been 19,996 individual reports over 1,215 weeks (average of 16 per week) on 332 different volcanoes.

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Agung Cuicocha Iliwerung Llaima Popocatepetl Sumbing
Ahyi Cumbal Inielika Lokon-Empung Purace Sundoro
Aira Dabbahu Ioto Lonquimay Puyehue-Cordon Caulle Suretamatai
Akan Davidof Irazu Lopevi Rabaul Suwanosejima
Alaid Dempo Iya Machin Raikoke Taal
Alu-Dalafilla Descabezado Grande Izu-Torishima Makushin Ranakah Tair, Jebel at
Ambae Dieng Volcanic Complex Jackson Segment Maly Semyachik Raoul Island Takawangha
Ambang Dukono Kaba Manam Rasshua Talang
Ambrym East Epi Kadovar Manda Hararo Raung Tambora
Anatahan Ebeko Kaitoku Seamount Marapi Redoubt Tanaga
Aniakchak Ebulobo Kama'ehuakanaloa Maroa Reventador Tandikat-Singgalang
Antillanca Volcanic Complex Edgecumbe Kambalny Martin Reykjanes Tangkoko-Duasudara
Antuco Egon Kanaga Masaya Rincon de la Vieja Tangkuban Parahu
Apoyeque Ekarma Kanlaon Maule, Laguna del Rinjani Tara, Batu
Arenal Eldey Karangetang Mauna Loa Ritter Island Ta'u
Asamayama Erebus Karkar Mayon Rotorua Taupo
Askja Erta Ale Karthala McDonald Islands Ruang Telica
Asosan Etna Karymsky Melebingoy Ruapehu Tenerife
Atka Volcanic Complex Etorofu-Yakeyama [Grozny Group] Kasatochi Melimoyu Ruby Tengger Caldera
Augustine Eyjafjallajokull Katla Merapi Ruiz, Nevado del Three Sisters
Avachinsky Fagradalsfjall Katmai Midagahara Sabancaya Tinakula
Awu Fernandina Kavachi Misti, El Sakar Tofua
Axial Seamount Fogo Kelimutu Miyakejima Salak Tokachidake
Azul, Cerro Fonualei Kelud Momotombo San Cristobal Tolbachik
Azumayama Fournaise, Piton de la Kerinci Monowai San Miguel Toliman
Bagana Fourpeaked Ketoi Montagu Island San Vicente Tongariro
Balbi Fuego Kharimkotan Moyorodake [Medvezhia] Sangay Trident
Bamus Fujisan Kick 'em Jenny Mutnovsky Sangeang Api Tungurahua
Banda Api Fukutoku-Oka-no-Ba Kie Besi Myojinsho Santa Ana Turrialba
Bardarbunga Galeras Kikai Nabro Santa Maria Ubinas
Barren Island Galunggung Kilauea Negra, Sierra Sao Jorge Ugashik-Peulik
Batur Gamalama Kirishimayama Negro, Cerro Sarigan Ukinrek Maars
Bezymianny Gamkonora Kita-Ioto Nightingale Island Sarychev Peak Ulawun
Bogoslof Gareloi Kizimen Nishinoshima Saunders Unnamed
Brava Gaua Klyuchevskoy Nisyros Savo Unnamed
Bristol Island Gorely Kolokol Group Novarupta Semeru Veniaminof
Bulusan Great Sitkin Koryaksky NW Rota-1 Semisopochnoi Villarrica
Calbuco Grimsvotn Krakatau Nyamulagira Seulawah Agam Vulcano
Callaqui Guagua Pichincha Krummel-Garbuna-Welcker Nyiragongo Sheveluch West Mata
Cameroon Guallatiri Krysuvik-Trolladyngja Ofu-Olosega Shishaldin Westdahl
Campi Flegrei del Mar di Sicilia Guntur Kuchinoerabujima Okataina Simbo Whakaari/White Island
Cayambe Hachijojima Kurikomayama Okmok Sinabung Witori
Chachadake [Tiatia] Hakoneyama Kusatsu-Shiranesan Ontakesan Sinarka Wolf
Chaiten Heard Kverkfjoll Oraefajokull Siple Wrangell
Chiginagak Hekla La Palma Osorno Sirung Yakedake
Chikurachki Helgrindur Lamington Pacaya Slamet Yasur
Chiles-Cerro Negro Hierro Lamongan Pagan Snaefellsjokull Yufu-Tsurumi
Chillan, Nevados de Hokkaido-Komagatake Langila Palena Volcanic Group Soputan Zaozan [Zaosan]
Chirinkotan Home Reef Lanin Paluweh Sorikmarapi Zavodovski
Chirpoi Hood Lascar Panarea Sotara Zhupanovsky
Ciremai Huaynaputina Late Papandayan Soufriere Hills Zubair Group
Cleveland Hudson, Cerro Lateiki Pavlof Soufriere St. Vincent
Colima Huila, Nevado del Lengai, Ol Doinyo Pelee South Sarigan Seamount
Colo Hunga Tonga-Hunga Ha'apai Leroboleng Peuet Sague Spurr
Concepcion Ibu Lewotobi Pinatubo St. Helens
Copahue Ijen Lewotolok Planchon-Peteroa Stromboli
Cotopaxi Iliamna Little Sitkin Poas Sulu Range
 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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A Google Earth network link for the Weekly Volcanic Activity Report can be loaded into the free Google Earth software, and in turn will load placemarks for volcanoes in the current weekly report. Placemark balloons include the volcano name, report date, report text, sources, and links back to the GVP volcano profile page and to the complete Weekly Report for that week. This feature was first made available on 1 April 2009.

 Criteria & Disclaimers

Criteria



The Weekly Volcanic Activity Report does not necessarily include all volcanic activity that occurred on Earth during the week. More than a dozen volcanoes globally have displayed more-or-less continuous eruptive activity for decades or longer, and such routine activity is typically not reported here. Moreover, Earth's sea-floor volcanism is seldom reported even though in theory it represents the single most prolific source of erupted material. The Weekly Volcanic Activity Report summarizes volcanic activity that meets one or more of the following criteria:

- A volcano observatory raises or lowers the alert level at the volcano.
- A volcanic ash advisory has been released by a volcanic ash advisory center (VAAC) stating that an ash cloud has been produced from the volcano.
- A verifiable news report of new activity or a change in activity at the volcano has been issued.
- Observers have reported a significant change in volcanic activity. Such activity can include, but is not restricted to, pyroclastic flows, lahars, lava flows, dome collapse, or increased unrest.

Volcanoes are included in the "New Activity/Unrest" section of the Weekly Volcanic Activity Report if the activity occurs after at least 3 months of quiescence. Once a volcano is included in the "New Activity/Unrest" section, updates will remain in that section unless the activity continues for more than 1 month without escalating, after which time updates will be listed in the "Continuing Activity" section. Volcanoes are also included in the "New Activity/Unrest" section if the volcano is undergoing a period of relatively high unrest, or increasing unrest. This is commonly equal to Alert Level Orange on a scale of Green, Yellow, Orange, Red, where Red is the highest alert. Or alert level 3 on a scale of 1-4 or 1-5.

It is important to note that volcanic activity meeting one or more of these criteria may occur during the week, but may not be included in the Weekly Volcanic Activity Report because we did not receive a report.

Disclaimers



1. The Weekly Volcanic Activity Report is intended to provide timely information about global volcanism on a weekly basis. Consequently, the report is generated rapidly by summarizing volcanic reports from various sources, with little time for fact checking. The accuracy of the Weekly Volcanic Activity Report is dependent upon the quality of the volcanic activity reports we receive. Reports published in the Bulletin of the Global Volcanism Network are cover longer time periods and are more carefully reviewed, although all of the volcanoes discussed in the Weekly Volcanic Activity Report are not necessarily reported in the Bulletin. Because of our emphasis on rapid reporting on the web we have avoided diacritical marks. Reports are updated on the Weekly Volcanic Activity Report web page as they are received, therefore information may be included regarding events that occurred before the current report period.

2. Rapidly developing events lead to coverage that is often fragmentary. Volcanoes, their eruptions, and their plumes and associated atmospheric effects are complex phenomena that may require months to years of data analysis in order to create a comprehensive summary and interpretation of events.

3. Preliminary accounts sometimes contain exaggerations and "false alarms," and accordingly, this report may include some events ultimately found to be erroneous or misleading.

4. Many news agencies do not archive the articles they post on the Internet, and therefore the links to some sources may not be active. To obtain information about the cited articles that are no longer available on the Internet contact the source.

5. USGS Disclaimer Statement for this Website:

Information presented on this website is considered public information and may be distributed or copied. Use of appropriate byline/photo/image credit is requested. We strongly recommend that USGS data be acquired directly from a USGS server and not through other sources that may change the data in some way. While USGS makes every effort to provide accurate and complete information, various data such as names, telephone numbers, etc. may change prior to updating. USGS welcomes suggestions on how to improve our home page and correct errors. USGS provides no warranty, expressed or implied, as to the accuracy, reliability or completeness of furnished data.

Some of the documents on this server may contain live references (or pointers) to information created and maintained by other organizations. Please note that USGS does not control and cannot guarantee the relevance, timeliness, or accuracy of these outside materials.

For site security purposes and to ensure that this service remains available to all users, this government computer system employs software programs to monitor network traffic to identify unauthorized attempts to upload or change information, or otherwise cause damage. Unauthorized attempts to upload information or change information on this website are strictly prohibited and may be punishable under the Computer Fraud and Abuse Act of 1986 and the National Information Infrastructure Protection Act. Information may also be used for authorized law enforcement investigations. (Last modified September 21, 1999.)

U.S. Department of the Interior, U.S. Geological Survey, Reston, VA, USA
URL: https://volcano.si.edu/reports_weekly.cfm

 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 Cleveland
On 4 June AVO reported that no explosions from Cleveland had been detected since 6 May, and there was no evidence of lava effusion since 13 May. Weakly elevated surface temperatures detected in recent clear-weather satellite images were consistent with cooling of a newly emplaced lava flow. AVO lowered the Volcanic Alert Level to Advisory and the Aviation Color Code to Yellow.
Source: US Geological Survey Alaska Volcano Observatory (AVO)
Report for Copahue
OVDAS-SERNAGEOMIN reported that during 28-29 May seismicity at Copahue had decreased with respect to the previous 24-hour period; the majority of the signals were low-magnitude hybrid events, detected at an average rate of 127 per hour. Meteorological cloud cover prevented visual observations. During 29-30 May seismicity again decreased; earthquakes were detected at a rate of 40 events per hour. A camera near the volcano recorded a white plume that rose 100-200 m and drifted SE. The seismic network continued to record a downward trend during 30-31 May, with 120 events per hour detected during the night. By the time of the release of the report at 1700 on 31 May about 20 events per hour were being detected. Visual observations were again inhibited due to weather conditions. About 42 events per hour were recorded during 31 May-1 June, about 52 events per hour were detected during 1-2 June, and about 102 events per hour were detected during 2-3 June. A small plume rose 80 m above the crater during 2-3 June. ONEMI reported on 3 June that about 280 people, of 2,440 people, remained within the 25-km evacuation zone. That same day SERNAGEOMIN lowered the Alert Level to Orange.
Sources: Servicio Nacional de Geología y Minería (SERNAGEOMIN), Oficina Nacional de Emergencia-Ministerio del Interior (ONEMI)
Report for Kikai
Based on information from JMA, the Tokyo VAAC reported that on 4 June an ash plume from Kikai drifted W.
Source: Tokyo Volcanic Ash Advisory Center (VAAC)
Report for Mayon
PHIVOLCS reported that during 30-31 May diffuse, short-lived, bluish, hydrogen sulfide emissions rose from Mayon, and incandescence from the crater was observed. Sulfur dioxide emissions fluctuated between 5 and 388 tonnes per day, remaining below the normal level of 500 tonnes per day. Seismicity was low, while a recently concluded ground deformation survey indicated slight inflation compared to February survey data. Based on the visual observations, and despite that most monitoring parameters remained within baseline levels, PHIVOLCS raised the Alert Level to 1 and reminded the public not to enter the 6-km-radius Permanent Danger Zone (PDZ).
Source: Philippine Institute of Volcanology and Seismology (PHIVOLCS)
Report for Pavlof
AVO reported that ash emissions at Pavlof began at approximately 1100 on 4 June as observed in satellite images and by pilots. Satellite images showed an ash cloud drifting SE, and pilots estimated that the cloud was at an altitude of 5.8 km (19,000 ft) a.s.l. Weak seismicity that began at 1057 accompanied the emissions, and then continued. The Volcanic Alert Level was increased to Watch and the Aviation Color Code was increased Orange.
Source: US Geological Survey Alaska Volcano Observatory (AVO)
Report for Popocatepetl
CENAPRED reported that during 29 May-4 June seismicity at Popocatépetl indicated continuing gas-and-steam emissions that contained variable amounts of ash; cloud cover often prevented visual confirmation. Incandescence from the crater was often observed at night. On most days steam-and-gas plumes were observed drifting SW and SSW. Some periods of high-frequency and low-amplitude tremor were detected on 31 May and 1 June. During the early morning on 3 June a continuous plume of steam and ash was observed drifting SW. Later that day an ash plume rose 1 km on 3 June. The Alert Level remained at Yellow, Phase Three.
Source: Centro Nacional de Prevencion de Desastres (CENAPRED)
Report for Turrialba
OVSICORI-UNA reported that on 29 May a pilot flying past Turrialba about 40 km away observed a blackish plume. Officials from the Parque Nacional Volcán Turrialba observed a gas plume that was slightly darker than usual between 0730 and 0745; seismic records showed no abnormal activity at those times or during the previous 48 hours. In addition, web camera images showed no noticeable ash emissions since 23 May. Gas plumes over 750 degrees Celsius were emitted from Boca 2010 (on the W wall) and Boca 2012 (on the E wall). The plume from Boca 2010 was whiter than the plume emitted from Boca 2012, mainly due to the difference in the ratio of magmatic gases and aerosols, and no ash.

On 4 June slight ashfall was reported in Pacayas and San Pablo in Oreamuno de Cartago (25 km SW). An observer in the National Park noted that between 1400 and 1500 gas emissions were slightly stronger and also grayish.
Source: Observatorio Vulcanologico y Sismologico de Costa Rica-Universidad Nacional (OVSICORI-UNA)
Report for Aira
JMA reported that during 27-31 May Sakura-jima's Showa Crater had four explosions, ejecting tephra that fell at most 1.3 km from the crater. Crater incandescence was occasionally detected at night. A small pyroclastic flow traveled 700 m down the E flank. A pyroclastic flow also occurred in the crater. Based on information from JMA, the Tokyo VAAC reported that on 30 May explosions produced plumes that rose to altitudes of 2.1-2.4 km (7,000-8,000 ft) a.s.l. and drifted E. An explosion was detected on 1 June, and on 2 June an explosion produced an ash plume that rose 1.5 km (5,000 ft) a.s.l.
Sources: Japan Meteorological Agency (JMA), Tokyo Volcanic Ash Advisory Center (VAAC)
Report for Bagana
Based on analyses of satellite imagery and wind data, the Darwin VAAC reported that on 4 June an ash plume from Bagana rose to an altitude of 2.4 km (8,000 ft) a.s.l. and drifted over 35 km W.
Source: Darwin Volcanic Ash Advisory Centre (VAAC)
Report for Fuego
INSIVUMEH reported that rumbling and sounds resembling jet engines were heard from Fuego during 28-30 May; cloud cover often inhibited visual observations of the crater. On 29 May a lahar carrying blocks up to 50 cm in diameter traveled SE down the Las Lajas and El Jute drainages. On 30 May a plume was observed rising 200 m above the crater and drifting S. During 1-2 and 4 June explosions generated ash plumes that rose at most 800 m and drifted 5-8 km W and NW. Incandescent material was ejected 100 m above the crater and generated avalanches. On 2 June heavy rain caused lahars that traveled down the Ceniza drainage, carrying trees, logs, and blocks. On 3 June diffuse white plumes rose 200 m.
Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)
Report for Karymsky
KVERT reported that weak seismic activity was detected at Karymsky during 25-26 May; technical problems prevented seismic data collection on the other days during 24-31 May. Satellite data showed a thermal anomaly on the volcano on 25 and 28 May, during periods of clearer weather conditions. The Aviation Color Code remained at Orange.
Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
Report for Kilauea
During 29 May-4 June HVO reported that the circulating lava lake occasionally rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas.

At Pu'u 'O'o Crater, glow emanated from three spatter cones and a small lava pond on the E part of the crater floor. The Kahauale’a II lava flows traveled N from the base of Pu'u 'O'o cone. The most distal front of the flow was 1.8 km from its source at a spatter cone on the NE edge of Pu'u 'O'o's crater floor. At 0740 on 26 May lava began to spill from the N side of the NE spatter cone, feeding a new breakout on the N flank of Pu'u 'O'o. .

Peace Day activity, fed by lava tubes extending from Pu'u 'O'o, consisted of some breakout activity on the pali and coastal plain, but mainly flows entering the ocean at locations inside and outside the National Park boundary.
Source: US Geological Survey Hawaiian Volcano Observatory (HVO)
Report for Kizimen
KVERT reported that during 24-31 May moderate seismic activity continued at Kizimen. Video and satellite data showed that lava continued to extrude from the summit, producing incandescence, strong gas-and-steam activity, and hot avalanches on the W and E flanks. A thermal anomaly was detected daily in satellite images. The Aviation Color Code remained at Orange.
Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
Report for Pacaya
INSIVUMEH reported that incandescence from Pacaya's crater was observed late at night on 28 May. Weather conditions prevented observations the next day. On 30 May a small effusive eruption occurred for about two hours. A small explosion ejected ash and lapilli 200 m above the crater that was then deposited within 400 m of the crater. Inclement weather prevented observations the rest of the day; however, the seismic network detected tremor and weak explosions.
Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)
Report for Poas
OVSICORI-UNA reported that during May temperatures of the cryptodome at Poás were high enough to produce nighttime incandescence. Maximum temperatures of 575 and 450 degrees Celsius were recorded on 8 and 30 May, respectively. Activity of the lake was very similar to that reported for May 2012, characterized by sporadic phreatic eruptions and a slow decline in the water level. On 8 May 2013 the water level was 0.5 m below the level measured on 8 May 2012. Phreatic eruptions occurred at 1100 on 1 May, at 1700 on 8 May, and at 1125 and 1510 on 28 May. Fumarolic activity was variable.

During the early morning hours on 2 and 3 June, residents reported a gas plume rising 1 km above the crater floor. OVSICORI-UNA noted that recent plumes were high-temperature (450-575 degrees Celsius) and rich in sulfur dioxide, giving the plumes a bluish-white color.
Source: Observatorio Vulcanologico y Sismologico de Costa Rica-Universidad Nacional (OVSICORI-UNA)
Report for Rabaul
RVO reported that during 17-31 May white vapor plumes sometimes containing fine ash rose at most 800 m from Rabaul caldera's Tavurvur cone and drifted NW and SE. Ashfall was reported in areas downwind including Rabaul town (3-5 km NW). Roaring and rumbling noises also continued. Seismicity was low, and slight inflation was detected at a station on Matupit Island (2 km W).
Source: Rabaul Volcano Observatory (RVO)
Report for Reventador
The Washington VAAC reported that on 1 June gas emissions from Reventador possibly contained diffuse ash. Ash was not detected in satellite images.
Source: Washington Volcanic Ash Advisory Center (VAAC)
Report for Santa Maria
INSIVUMEH reported that on 29 May white gas plumes rose 200 m above Santa María's Santiaguito lava-dome complex and drifted W. Avalanches occurred on the NE and S flanks of the dome. An explosion on 30 May generated an ash plume that rose 500 m; ashfall was reported in Calahuaché village. On 1 June a weak lahar descended the Nima I drainage on the SE flank, and on 2 June dense white plumes rose from the dome. At 1855 on 4 June a lahar again descended the Nima I drainage and was about 40 m wide and 2.5 m thick.
Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)
Report for Sheveluch
Based on visual observations and analyses of satellite data, KVERT reported that during 24-31 May a viscous lava flow effused on the N flank of Shiveluch's lava dome, accompanied by hot avalanches, incandescence, and fumarolic activity. Satellite imagery showed a daily thermal anomaly on the lava dome. The Aviation Color Code remained at Orange.
Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
Report for Tolbachik
KVERT reported that the S fissure along the W side of Tolbachinsky Dol, a lava plateau on the SW side of Tolbachik, continued to produce very fluid lava flows during 24-31 May that traveled to the W, S, and E sides of the plateau. Cinder cones continued to grow along the S fissure and weak gas-and-steam plumes were observed. A large thermal anomaly on the N part of Tolbachinsky Dol was visible daily in satellite imagery. The Aviation Color Code remained at Orange.
Source: Kamchatkan Volcanic Eruption Response Team (KVERT)