Logo link to homepage

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, notices of volcanic activity posted on these pages are preliminary and subject to change as events are studied in more detail.

This is not a comprehensive list of all of Earth's volcanoes erupting during the week, but rather a summary of activity that meet criteria discussed in detail in the "Criteria and Disclaimers" section. Carefully reviewed, detailed narratives on various volcanoes are published as reports of the Bulletin of the Global Volcanism Network.

Smithsonian / USGS Weekly Volcanic Activity Report for the week of 11 May-17 May 2016
Name Location Eruption Start Date Report Status
Awu Sangihe Islands (Indonesia) New
Ruapehu North Island (New Zealand) New
Aira Kyushu (Japan) 2017 Mar 25 Continuing
Alaid Kuril Islands (Russia) Continuing
Chirpoi Kuril Islands (Russia) Continuing
Cleveland Chuginadak Island (USA) Continuing
Colima Mexico Continuing
Cotopaxi Ecuador Continuing
Dukono Halmahera (Indonesia) 1933 Aug 13 Continuing
Kilauea Hawaiian Islands (USA) 2020 Dec 20 Continuing
Klyuchevskoy Central Kamchatka (Russia) 2019 Apr 9 Continuing
Langila New Britain (Papua New Guinea) 2015 Oct 22 (?) Continuing
Masaya Nicaragua 2015 Oct 3 Continuing
Nevado del Ruiz Colombia 2014 Nov 18 Continuing
Pavlof United States Continuing
Sangay Ecuador 2019 Mar 26 Continuing
Sheveluch Central Kamchatka (Russia) 1999 Aug 15 Continuing
Sinabung Indonesia 2020 Aug 8 Continuing
Telica Nicaragua Continuing
Turrialba Costa Rica Continuing
Weekly Reports Archive

Since the Weekly Volcanic Activity Report began in November 2000, there have been 16,627 individual reports over 1,061 weeks (average of 16 per week) on 312 different volcanoes.

Search by Date



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

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



Search by Volcano



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
 News Feeds and Google Placemarks


Download Smithsonian / USGS Weekly Volcanic Activity Report Network RSS Feed

The RSS (Really Simple Syndication) feed is identical to the Weekly Volcanic Activity Report minus some features including the header information (latitude and longitude and summit elevation), the Geologic Summary, and a link to the volcano's page from the Global Volcanism Program. At the end of each report is a list of the sources used. Each volcano report includes a link from the volcano's name back to the more complete information in the Weekly Volcanic Activity Report on the Smithsonian website. This feature was first made available on 5 March 2008.



Download Smithsonian / USGS Weekly Volcanic Activity Report Network CAP Feed

The CAP (Common Alerting Protocol) feeds are XML files specifically formatted for disaster management. They are similar in content to the RSS feed, but contain no active links.



Download Smithsonian/USGS Weekly Volcanic Activity Report Network Link Download Smithsonian / USGS Weekly Volcanic Activity Report Network Link

A Google Earth network link for the Weekly Volcanic Activity Report can be loaded into the free Google Earth software, and in turn will load placemarks for volcanoes in the current weekly report. Placemark balloons include the volcano name, report date, report text, sources, and links back to the GVP volcano profile page and to the complete Weekly Report for that week. This feature was first made available on 1 April 2009.

 Criteria & Disclaimers

Criteria



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

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

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

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

Disclaimers



1. The Weekly Volcanic Activity Report is intended to provide timely information about global volcanism on a weekly basis. Consequently, the report is generated rapidly by summarizing volcanic reports from various sources, with little time for fact checking. The accuracy of the Weekly Volcanic Activity Report is dependent upon the quality of the volcanic activity reports we receive. Reports published in the Bulletin of the Global Volcanism Network are 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 Awu
PVMBG reported that seismicity at Awu fluctuated during April and the first part of May. On 11 May the number of earthquakes rose significantly; the number of local tectonic and deep volcanic earthquakes was the highest recorded in the last year, and the number of shallow volcanic earthquakes was the second highest recorded (the highest number was recorded on 24 November 2015, prompting an increase in the Alert Level). Earthquake hypocenters were located at depths between 0.5 and 4 km. On 12 May the Alert Level was raised to 3 (on a scale of 1-4); residents and tourists were advised to stay 4 km away from the crater.
Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)
Report for Ruapehu
On 17 May GeoNet reported that the lake temperature of Ruapehu's summit Crater Lake had decreased from a high of 46 degrees Celsius to 39 degrees, with some of the decrease attributed to rain and snowfall. Moderate levels of volcanic tremor continued, and analysis of water samples collected the previous week showed no changes in the lake chemistry. During recent visits, scientists measured a larger output of volcanic gases. The Volcanic Alert Level remained at 2 (moderate to heightened unrest) and the Aviation Colour Code remained at Yellow.
Source: GeoNet
Report for Aira
JMA reported that an explosion at the Minamidake summit crater (at Aira Caldera’s Sakurajima volcano) generated an ash plume that rose 3.7 km above the crater rim. During 13-16 May explosions from Showa Crater generated an ash plume that rose as high as 3.5 km above the crater rim. On 13 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 6-13 May. Satellite images showed an intense daily thermal anomaly over the volcano and a lava flow on the SW flank. 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 Chirpoi
SVERT reported that a weak thermal anomaly over Snow, a volcano of Chirpoi, was detected in satellite images during 9-11 and 14 May. The Aviation Color Code remained at Yellow.
Source: Sakhalin Volcanic Eruption Response Team (SVERT)
Report for Cleveland
AVO reported that an explosion at Cleveland was detected at 0732 on 10 May by infrasound (air pressure) sensors. Cloud cover prevented satellite views during most of the previous week; nothing noteworthy was detected in satellite data and no anomalous seismicity was recorded after the explosion through 14 May. Energetic steaming and highly elevated surface temperatures in the summit crater were observed in satellite data on 15 May. 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 and webcam views, the Washington VAAC reported that duirng 15-17 May ash plumes from Colima rose to altitudes of 5.5-7.6 km (18,000-25,000 ft) a.s.l. and drifted ENE and E.
Source: Washington Volcanic Ash Advisory Center (VAAC)
Report for Cotopaxi
During an overflight of Cotopaxi on 10 May, scientists observed minor gas emissions rising 600 m above the crater and drifting N and NW. Glaciers remained cracked, though glacial melting observed in recent months had decreased considerably. The temperature of flank fumaroles had decreased slightly.
Source: Instituto Geofísico-Escuela Politécnica Nacional (IG)
Report for Dukono
Based on analyses of satellite imagery and wind data, and notices from PVMBG, the Darwin VAAC reported that during 11-17 May ash plumes from Dukono rose to an altitude of 2.1 km (7,000 ft) a.s.l. and drifted as far as 65 km in multiple directions.
Source: Darwin Volcanic Ash Advisory Centre (VAAC)
Report for Kilauea
HVO reported that seismicity beneath Kilauea's summit, upper East Rift Zone, and Southwest Rift Zone was at background levels during 11-17 May. The lava lake continued to circulate and eject spatter in the Overlook vent. 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. Vents in the SW and E parts of the crater periodically produced small lava flows within the crater. The June 27th NE-trending lava flow continued to be active within 5.8 km NE of Pu'u 'O'o Crater.
Source: US Geological Survey Hawaiian Volcano Observatory (HVO)
Report for Klyuchevskoy
KVERT reported that a Strombolian eruption at Klyuchevskoy continued during 6-13 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. The Aviation Color Code was raised to Orange.
Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
Report for Langila
Based on analyses of satellite imagery and wind data, the Darwin VAAC reported that during 11-13 May ash plumes from Langila rose to an altitude of 2.1 km (7,000 ft) a.s.l. and drifted 25-85 km NNW, NW, and W.
Source: Darwin Volcanic Ash Advisory Centre (VAAC)
Report for Masaya
INETER reported that between 1700 and 2400 on 3 May volcanic tremor at Masaya increased; RSAM values spiked at 1,000 units and then dropped to 250. Gas emissions at Santiago crater were at low-to-moderate levels, and the lava lake continued to strongly circulate. On 5 May RSAM values fluctuated between 250 and 500 units which are low-to-moderate values.
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 10-16 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. Thermal anomalies near Arenas Crater were identified in satellite images during 11-12 May. Significant amounts of water vapor and gas rose from the crater during the week. A gas, steam, and ash plume rose 1.7 km and drifted NW and W on 12 May. 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: Washington Volcanic Ash Advisory Center (VAAC), Servicio Geológico Colombiano (SGC)
Report for Pavlof
AVO reported that at about 1035 on 13 May seismic activity at Pavlof increased to levels typically associated with low-level eruptive activity; cloud cover prevented visual observations of the volcano though no thermal signals or ash emissions were evident through the cloud deck. AVO raised the Aviation Color Code to Orange and the Volcano Alert Level to Watch due to the possibility of an eruption in progress. On 14 May seismicity remained above background levels. Clear satellite and webcam views revealed no evidence for an eruption, and no ash emissions or thermal anomalies at the summit were observed. During 1927-2107 on 14 May ash emissions were evident in webcam views and reported by local observers. A diffuse ash plume rose to altitudes of 4.6-5.5 km (15,000-18,000 ft) a.s.l. and remained in the vicinity of the volcano. Elevated surface temperatures were detected in satellite data at 0850 on 15 May. Periods of elevated volcanic tremor and a small explosion associated with minor ash emissions began at 0445 on 17 May; observers in Cold Bay (60 km SE) and Sand Point (90 km E) reported ash emissions interspersed with steam emissions. A National Weather Service SIGMET noted that ash was below an altitude of 4.6 km (15,000 ft) a.s.l.
Source: US Geological Survey Alaska Volcano Observatory (AVO)
Report for Sangay
IG reported that at the beginning of March Sangay began a new phase of activity which continued through at least 12 May without significant changes. The number of tremor events and long-period earthquakes were slightly higher in March as compared to the number recorded in April and May, and the number of explosions was slightly higher in April and May. Surficial activity was characterized by frequent ash emissions generated by explosive activity. Thermal anomalies on the flanks were also detected, mostly within 5 km of the summit crater, which possibly corresponded to short-range pyroclastic flows and lava flows. No abnormal sulfur dioxide emission were detected.
Source: Instituto Geofísico-Escuela Politécnica Nacional (IG)
Report for Sheveluch
KVERT reported that during 6-13 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
BNPB reported that a lahar passed through Kutambaru village, 20 km NW of Sinabung and near the Lau Barus River, at 1545 on 9 May, killing one person and injuring four more. One person was missing. A news article noted that three houses were also damaged. Based on satellite images and information from PVMBG, the Darwin VAAC reported that during 11-13 and 16 May ash plumes rose to altitudes of 3-4.5 km (10,000-15,000 ft) a.s.l. and drifted SW, W, WNW, and NW.
Sources: Badan Nacional Penanggulangan Bencana (BNPB), Darwin Volcanic Ash Advisory Centre (VAAC), Okezone
Report for Telica
Based on information from INETER, SINAPRED reported that 30 explosion at Telica occurred during 7-8 May, producing gas-and-ash plumes that rose 600 m and drifted S and SW. The explosions originated from a new vent in the N part of the crater; lava emissions were also observed. INETER reported high micro-seismicity and low outgassing during 11-16 May. Incandescence from vents on the crater floor was visible during 11-12 May; sounds from jetting gasses were noted on 11 May. RSAM values were 180-190 units during 11-12 May, dropping to 80 units during 12-14 May.
Sources: Instituto Nicaragüense de Estudios Territoriales (INETER), Sistema Nacional para la Prevención, Mitigación y Atención de Desastres (SINAPRED)
Report for Turrialba
OVSICORI-UNA reported that an explosion at Turrialba at 1140 on 16 May generated gas-and-ash emissions, though the height of the plume was not determined due to fog. Wind models suggested that the ash plume rose 3 km above the crater and drifted WNW towards Valle Central. Officials on farms 2.5 km WNW reported abundant ashfall. Sustained tremor with significant and highly-variable amplitude continued to be recorded. On 17 May gas-and-steam emissions, intermittently but frequently containing ash, were recorded by the webcam. Throughout the day volcanic tremor amplitude decreased substantially, though numerous earthquakes continued to be recorded. Ash emissions gradually ended. At 1800 the seismic network began recording a large number of very-long-period earthquake, and at around 2200 volcanic tremor with significant amplitude was detected. Seismicity remained high the next morning.
Source: Observatorio Vulcanologico y Sismologico de Costa Rica-Universidad Nacional (OVSICORI-UNA)