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 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 August-4 September 2018
Name Country Volcanic Province Eruption Start Date Report Status
Krakatau Indonesia Sunda Volcanic Arc New
Manam Papua New Guinea Bismarck Volcanic Arc 2018 May 10 ± 10 days New
Veniaminof United States Aleutian Ridge Volcanic Arc New
Aira Japan Ryukyu Volcanic Arc 2017 Mar 25 Continuing
Ambae Vanuatu Vanuatu Volcanic Arc Continuing
Dukono Indonesia Halmahera Volcanic Arc 1933 Aug 13 Continuing
Ebeko Russia Kuril Volcanic Arc 2022 Jun 11 Continuing
Fuego Guatemala Central America Volcanic Arc 2002 Jan 4 Continuing
Karymsky Russia Eastern Kamchatka Volcanic Arc 2024 Jun 20 Continuing
Kilauea United States Hawaiian-Emperor Hotspot Volcano Group 2024 Sep 15 Continuing
Mayon Philippines Eastern Philippine Volcanic Arc Continuing
Reventador Ecuador Northern Andean Volcanic Arc 2008 Jul 27 Continuing
Rincon de la Vieja Costa Rica Central America Volcanic Arc 2021 Jun 28 Continuing
Sabancaya Peru Central Andean Volcanic Arc 2016 Nov 6 Continuing
Sangay Ecuador Northern Andean Volcanic Arc 2019 Mar 26 Continuing
Santa Maria Guatemala Central America Volcanic Arc 1922 Jun 22 Continuing
Semeru Indonesia Sunda Volcanic Arc 2017 Jun 6 Continuing
Sheveluch Russia Eastern Kamchatka Volcanic Arc 1999 Aug 15 Continuing
Sierra Negra Ecuador Galapagos Hotspot Volcano Group Continuing
Turrialba Costa Rica Central America 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 20,627 individual reports over 1,243 weeks (average of 17 per week) on 338 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



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
 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 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 Krakatau
Based on satellite data, the Darwin VAAC reported that during 29-30 August and during 3-4 September ash plumes from Anak Krakatau rose to altitudes of 1.2-1.5 km (4,000-5,000 ft) a.s.l. and drifted SW, W, NW, and N. The Alert Level remained at 2 (on a scale of 1-4); residents and visitors were warned not to approach the volcano within 2 km of the crater.
Sources: Darwin Volcanic Ash Advisory Centre (VAAC), Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)
Report for Manam
RVO reported that during 26 August-3 September white plumes rose from Manam’s Main and Southern craters. Seismicity was at low levels.
Source: Rabaul Volcano Observatory (RVO)
Report for Veniaminof
Late on 2 September seismic activity at Veniaminof increased, indicative of unrest, prompting AVO to raise the Aviation Color Code to Yellow and the Volcano Alert Level to Advisory. The report noted no other signs of eruptive activity.
Source: US Geological Survey Alaska Volcano Observatory (AVO)
Report for Aira
JMA reported that there were 14 events and 15 explosions at Minamidake crater (at Aira Caldera’s Sakurajima volcano) during 27 August-3 September, with ash plumes rising as high as 2.8 km above the crater rim and material ejected as far as 1.3 km. Crater incandescence was occasionally visible at night. The sulfur dioxide emission rate was 1,500 tons/day on 27 August. The Alert Level remained at 3 (on a 5-level scale).
Source: Japan Meteorological Agency (JMA)
Report for Ambae
The Vanuatu Meteorology and Geo-hazards Department reported that at 2015 on 1 September explosions at Ambae’s Lake Voui generated ash plumes that rose 4-11 km above the crater rim. According to the Wellington VAAC the ash plumes were visible in satellite images rising as high as 10.7 km (35,000 ft) a.s.l. and drifting E; the ash quickly dissipated. Moderate ashfall was likely produced in areas NE and E. The Alert Level remained at 3 (on a scale of 0-5).
Source: Vanuatu Meteorology and Geohazards Department (VMGD)
Report for Dukono
Based on satellite data, wind model data, and notices from PVMBG, the Darwin VAAC reported that during 29 August-4 September ash plumes from Dukono rose to altitudes of 1.8-2.1 km (6,000-7,000 ft) a.s.l. and drifted N, NE, and E.
Source: Darwin Volcanic Ash Advisory Centre (VAAC)
Report for Ebeko
Volcanologists in Severo-Kurilsk (Paramushir Island), about 7 km E of Ebeko, observed explosions during 24-31 August that sent ash plumes to 3-6 km (17,100 ft) a.s.l. A thermal anomaly was visible in satellite data during 24-25 and 30 August. Ash plumes drifted about 135 km SE, S, and SW during 24-25 and 27-30 August, producing ashfall on 29 and 30 August. 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 Fuego
INSIVUMEH reported that heavy rain generated lahars during 29 August-1 September that descended Fuego’s El Jute (SE), Las Lajas (SE), Cenizas (SSW), Taniluyá (SW), Seca (W), Mineral, Honda, and Pantaleón (W) drainages. The lahars were hot, had a sulfur odor, and carried tree branches and blocks (2-3 m in diameter). On 1 September lahars disrupted roads between San Pedro Yepocapa (8 km NW) and Sangre de Cristo (8 km WSW), and from Finca Palo Verde and El Porvenir (8 km ENE). During 2-4 September explosions produced ash plumes that rose as high as 950 m above the crater rim and drifted 10-15 km W and SW. Avalanches of incandescent material were confined to the crater. Ashfall was reported in areas downwind including San Pedro Yepocapa, Sangre de Cristo, Panimaché I and II (8 km SW), Morelia (9 km SW), and Finca Palo Verde.
Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)
Report for Karymsky
KVERT reported that an ash plume from Karymsky was identified in satellite images drifting about 40 km S on 25 August. The Aviation Color Code remained at Orange (the second highest level on a four-color scale).
Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
Report for Kilauea
HVO reported a break in visible lava activity at Kilauea’s Fissure 8 during 26-31 August. On 1 September incandescence at Fissure 8 was evident in the afternoon; spattering from a small area produced lava flows that slowly covered the 15 x 65 m crater floor by the evening. Lava continued to fill the Fissure 8 crater on 3 September. The Volcano Alert Level remained at Watch and the Aviation Color Code remained at Orange.
Source: US Geological Survey Hawaiian Volcano Observatory (HVO)
Report for Mayon
PHIVOLCS reported that at 0653 on 27 August a short-lived degassing event at Mayon produced a light-brown ash plume that rose 200 m above the summit rim and drifted NE. During 28 August-3 September white steam plumes rose as high as 1 km and drifted in multiple directions. Crater incandescence was visible nightly. The Alert Level remained at 2 (on a 0-5 scale) and PHIVOLCS reminded residents to stay away from the 6-km-radius Permanent Danger Zone and the 7-km Extended Danger Zone on the SSW and ENE flanks.
Source: Philippine Institute of Volcanology and Seismology (PHIVOLCS)
Report for Reventador
During 29 August-3 September IG reported a high level of seismic activity at Reventador, including explosions, long-period earthquakes, harmonic tremor, and signals indicating emissions. Steam, gas, and ash plumes rose as high as 600 m above the crater rim and drifted NE, NW, and W. Crater incandescence was visible.
Source: Instituto Geofísico-Escuela Politécnica Nacional (IG-EPN)
Report for Rincon de la Vieja
OVSICORI-UNA reported two distinct, two-minute-long eruptions at Rincón de la Vieja beginning at 0434 and 1305 on 31 August. Weather conditions prevented webcam views and estimates of plume heights.
Source: Observatorio Vulcanologico y Sismologico de Costa Rica-Universidad Nacional (OVSICORI-UNA)
Report for Sabancaya
Observatorio Vulcanológico del Sur del IGP (OVS-IGP) and Observatorio Vulcanológico del INGEMMET (OVI) reported that explosions at Sabancaya averaged 25 per day during 27 August-2 September. Hybrid earthquakes were infrequent and of low magnitude. Gas-and-ash plumes rose as high as 3 km above the crater rim and drifted 50 km SE, E, and NE. The MIROVA system detected six thermal anomalies, and on 2 September the sulfur dioxide gas flux was high at 3,970 tons/day. The report noted that the public should not approach the crater within a 12-km radius.
Sources: Instituto Geológico Minero y Metalúrgico (INGEMMET), Instituto Geofísico del Perú (IGP)
Report for Sangay
Based on satellite images and wind model data, the Washington VAAC reported that during 28 August-3 September ash emissions from Sangay rose to 5.8-6.7 km (19,000-22,000 ft) a.s.l. and drifted over 45 km in multiple directions. A thermal anomaly was sometimes visible.
Source: Washington Volcanic Ash Advisory Center (VAAC)
Report for Santa Maria
INSIVUMEH reported that during 1-4 September weak explosions at Santa María's Santiaguito lava-dome complex generated ash plumes that rose 600-700 m and drifted SW. Avalanches of material descended the SE flanks of the lava dome. Ashfall was reported to the south in Monte Claro.
Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)
Report for Semeru
Based on analysis of satellite images and wind model data, the Darwin VAAC reported that on 4 September a discrete eruption at Semeru generated an ash plume that rose to an altitude of 4.3 km (14,000 ft) a.s.l. and drifted W.
Source: Darwin Volcanic Ash Advisory Centre (VAAC)
Report for Sheveluch
KVERT reported that a thermal anomaly over Sheveluch was identified in satellite data during 25 and 28-30 August; cloudy weather prevented views of the volcano on the other days during 24-31 August. 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 Sierra Negra
IG reported that the eruption at Sierra Negra that began on 26 June was divided into two main phases. The first and most energetic phase lasted one day (26 June) and was characterized by the opening of five fissures and lava flows traveling as far as 7 km from the vents. Lava was only produced from fissure 4 during the 57-day-long second phase (27 June-23 August), with lava reaching the sea on 6 July and expanding the coastline. By 25 August the lava flows in total covered an area of 30.6 square kilometers. Activity continued to decline the last week of August with decreased seismicity, gas emission, and no surficial activity visible.
Source: Instituto Geofísico-Escuela Politécnica Nacional (IG-EPN)
Report for Turrialba
OVSICORI-UNA reported that at 1340 on 30 August an event at Turrialba produced an ash plume that passively rose 200 m above the crater rim and drifted SW. Gas-and-ash emissions became continuous during 31 August-1 September, with plumes rising 200 m and drifting SW and W.
Source: Observatorio Vulcanologico y Sismologico de Costa Rica-Universidad Nacional (OVSICORI-UNA)