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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 31 July-6 August 2013
Name Country Volcanic Province Eruption Start Date Report Status
Karymsky Russia Eastern Kamchatka Volcanic Arc New
Ketoi Russia Kuril Volcanic Arc New
Popocatepetl Mexico Trans-Mexican Volcanic Belt 2005 Jan 9 New
Sheveluch Russia Eastern Kamchatka Volcanic Arc 1999 Aug 15 New
Tungurahua Ecuador Andean Northern Volcanic Arc New
Ulawun Papua New Guinea Bismarck Volcanic Arc New
Villarrica Chile Andean Southern Volcanic Arc 2014 Dec 2 ± 7 days New
Whakaari/White Island New Zealand Taupo Volcanic Zone New
Aira Japan Ryukyu Volcanic Arc 2017 Mar 25 Continuing
Chirinkotan Russia Kuril Volcanic Arc Continuing
Kilauea United States Hawaiian-Emperor Hotspot Volcano Group Continuing
Kizimen Russia Eastern Kamchatka Volcanic Arc Continuing
Manam Papua New Guinea Bismarck Volcanic Arc 2014 Jun 29 Continuing
Nyamulagira DR Congo Albertine Rift Zone 2018 Apr 18 Continuing
Nyiragongo DR Congo Albertine Rift Zone 2002 May 17 (?) Continuing
Rabaul Papua New Guinea Bismarck Volcanic Arc Continuing
Santa Maria Guatemala Central America Volcanic Arc 1922 Jun 22 Continuing
Tolbachik Russia Eastern Kamchatka Volcanic Arc Continuing
Veniaminof United States Aleutian Ridge 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 20,322 individual reports over 1,229 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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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 Karymsky
KVERT reported that technical problems prevented seismic data collection at Karymsky during 26 July-2 August. A thermal anomaly over the volcano was detected in satellite images during 29-31 July and 1 August; weather conditions prevented views on the other days.

On 6 August at 1035 a plume was observed by helicopter pilots (and confirmed by volcanologists at Tolbachik) rising 6 km (19,700 ft) a.s.l. and drifting 30 km E. An explosion at 1145 generated an ash cloud observed in satellite images that rose to an altitude of 4 km (13,100 ft) and drifted 45 km ESE. The ash cloud was 9 x 14 km. Ash plumes that were observed in satellite images at 1332 and 1512 rose to altitudes of 4.2 km (13,800 ft) and drifted 30 km ESE, and 4 km (13,100 ft) and drifted 80 km ESE, respectively. The Aviation Color Code remained at Orange.
Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
Report for Ketoi
SVERT reported that during 29-31 July a thermal anomaly from Ketoi's Pallas Peak was observed in satellite imagery. Gas-and-steam emissions were also observed on 29 July, and possibly observed on 31 July and 4 August. The Aviation Color Code remained at Yellow.
Source: Sakhalin Volcanic Eruption Response Team (SVERT)
Report for Popocatepetl
CENAPRED reported that during 31 July-6 August seismicity at Popocatépetl indicated continuing gas-and-steam emissions that sometimes contained ash; cloud cover often prevented visual confirmation. Incandescence from the crater was occasionally observed. On 31 July a clear decrease in the size of the water vapor and gas plumes was observed; plumes were pushed by winds down the NW flank and rose only 100 m above the crater rim. An explosion was detected at 2312 on 1 August, but cloud cover prevented confirmation of any ejecta. On 2 August minor amounts of ash fell in the Tepetlixpa, Atlautla, Ecatzingo, and Ozumba municipalities of Mexico State. On 4 August emissions of gas, steam, and ash drifted NW. During 5-6 August a few observed plumes rose 1-2 km and drifted WNW, W, and WSW. The Alert Level remained at to Yellow, Phase Two.
Source: Centro Nacional de Prevencion de Desastres (CENAPRED)
Report for Sheveluch
Based on visual observations and analyses of satellite data, KVERT reported that during 26 July-2 August a viscous lava flow effused on the NW flank of Shiveluch's lava dome, accompanied by hot avalanches, incandescence, and fumarolic activity. Satellite images detected a daily thermal anomaly.

A strong explosion at 2255 on 26 July generated ash plumes that rose as high as 10 km (23,800 ft) a.s.l. and drifted 520 km SE. Pyroclastic flows traveled 5 km. An ash cloud 15 x 7 km was observed in satellite images about 60 km SE of the volcano on 29 July. At 1707 on 4 August video images showed an ash plume rising to altitudes of 4.5-5 km (14,800-16,400 ft) a.s.l. and drifting 50 km E. The next day the seismic network detected an explosion at 1604; video images showed an ash plume rising to altitudes of 6.5-7 km (21,300-23,000 ft) a.s.l. and drifting 50 km ESE. The Aviation Color Code remained at Orange.
Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
Report for Tungurahua
IG reported that activity at Tungurahua remained high during 31 July-5 August; the seismic network detected explosions, emissions, and long-period earthquakes indicating fluid movement. Although cloud cover mostly prevented visual observations of the crater, plumes were occasionally observed. Roaring was also heard. Steam plumes with low ash content were observed on 31 July, and on 1 August drifting W. Ashfall was reported in Mocha (25 km WNW) on 31 July and in El Manzano (8 km SW) on 1 August. On 2 August a low-energy steam-and-ash emission was noted. During 2-3 August ash fell in El Manzano and Choglontus (SW).
Source: Instituto Geofísico-Escuela Politécnica Nacional (IG-EPN)
Report for Ulawun
RVO reported that activity at Ulawun was low during 22 July-4 August; emissions from the summit crater consisted of white vapor. Seismicity was also low. RSAM values decreased from 80 on 21 July to 50 on 31 July, and then began to increase on early 2 August. By 4 August RSAM values reached 600, attributed to an increase in volcanic tremor.
Source: Rabaul Volcano Observatory (RVO)
Report for Villarrica
According to Projecto Observación Visual Volcán Villarrica (POVI), satellite images of Villarrica acquired on 25 July revealed a weak thermal anomaly. On 29 July observers photographed the crater and described a thermal anomaly on the S edge of the crater rim, in the same area from which a lava flow originated on 29 December 1971. They also heard deep degassing sounds. A second photograph showed a diffuse gas plume rising from the bottom of the crater, and ash and lapilli on the snow on the inner crater walls.
Source: Proyecto Observación Villarrica Internet (POVI)
Report for Whakaari/White Island
On 5 August GeoNet Data Centre reported that minor activity at White Island had declined; the bursts of steam, gas, and mud observed the previous week were no longer visible in web cam images. The elevated volcanic tremor had decreased to near-background levels. The Volcano Alert Level remained at 1 (on a scale of 0-5) and the Aviation Colour Code was lowered to Green (on a four-color scale).
Source: GeoNet
Report for Aira
JMA reported that 10 explosions at Sakura-jima's Showa Crater were detected during 29 July-2 August and ejected tephra as far as 1.3 km. Incandescence from the crater was observed on 1 August. Based on information from JMA, the Tokyo VAAC reported that during 31 July-6 August explosions generated plumes that rose to altitudes of 1.5-3 km (5,000-10,000 ft) a.s.l. and drifted E, SE, and S. On 31 July and 4 August pilots observed ash plumes that rose to altitudes of 2.4-3 km (8,000-10,000 ft) a.s.l. and drifted E.
Sources: Japan Meteorological Agency (JMA), Tokyo Volcanic Ash Advisory Center (VAAC)
Report for Chirinkotan
Based on analysis of satellite images, SVERT reported that a thermal anomaly from Chirinkotan was observed during 29-31 July. The Aviation Color Code remained at Yellow.
Source: Sakhalin Volcanic Eruption Response Team (SVERT)
Report for Kilauea
During 31 July-6 August 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. The lake level was 51 m below the Halema'uma'u Crater floor on 5 August.

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 2 lava flow branches, fed by the NE spatter cone, were active as far NE as 3.2 km and as far NW as 2 km, and burned forest occasionally in two locations at the N edge of the 1983-1986 'a'a flows from 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, and an ocean entry outside of the National Park boundary to the E.
Source: US Geological Survey Hawaiian Volcano Observatory (HVO)
Report for Kizimen
KVERT reported that during 26 July-2 August 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 in satellite images during 29-31 July; cloud cover obscured views on the other days. The Aviation Color Code remained at Orange.
Source: Kamchatkan Volcanic Eruption Response Team (KVERT)
Report for Manam
RVO reported that activity at Manam's Southern and Main craters remained low during 22-31 July; observers noted white vapor plumes rising from the craters during periods of clear weather. Considerable amounts of blue vapor rose from Southern Crater during 25-26 July. Deep and low booming noises were heard on the island on most days since 24 July, however, on 30 July a loud explosion was heard in Bogia, 25-30 km SSW of Manam on the N coast of the mainland. Seismicity fluctuated but remained high.
Source: Rabaul Volcano Observatory (RVO)
Report for Nyamulagira
According to NASA's Earth Observatory, a satellite image acquired on 29 July showed a dense, white plume rising from Nyamuragira likely consisting of large amounts of water vapor.
Source: NASA Earth Observatory
Report for Nyiragongo
According to NASA's Earth Observatory, a satellite image of Nyiragongo acquired on 29 July showed a red glow coming from the active lava lake in the summit crater. A diffuse blue plume drifted N.
Source: NASA Earth Observatory
Report for Rabaul
RVO reported that during 22-31 July low-level activity consisted of discrete emissions of pale gray ash plumes occurring at short intervals. Some emissions were explosive and generated plumes that rose 2 km above the crater. Plumes drifted E, NE, N, NW, W, and SW, and deposited minor amounts of fine white and gray ash in areas downwind mainly between Namanula and Malaguna No. 1 (with Rabaul Town, 3-5 km NW, in between), and to a lesser extent between the Vulcan area and Malaguna No. 2. Roaring and rumbling noises also continued, often in conjunction with explosions.
Source: Rabaul Volcano Observatory (RVO)
Report for Santa Maria
INSIVUMEH reported that an explosion from Santa María's Santiaguito lava-dome complex at 0529 on 1 August generated an ash plume that rose 150 m above the crater and drifted SW. Ashfall was reported in the ranches of Monte Claro (S) and La Florida (5 km S). A few avalanches from the lava dome traveled short distances. On 4 August a weak explosion at 0613 produced a white plume that rose 300 m and drifted SW. Minor amounts of ash fell in Monte Claro, El Rosario (45 km SW), and Palajunoj (S). Avalanches were generated by the lava flow on the S flank. Seven explosions were detected during 5-6 August; the explosions generated avalanches on the NE flank, and degassing, jet-engine, and rumbling sounds. The last explosion was followed by a weak pyroclastic flow that traveled S and a moderate one that traveled SW. White and gray plumes rose 500-800 m. Ashfall was reported in the Palajunoj area. Later that day on 6 August OVSAN reported that explosions were heard, and ash plumes that rose 500-800 m drifted W and SW.
Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)
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 26 July-2 August 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 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)
Report for Veniaminof
AVO reported that the ongoing low-level eruption of Veniaminof, characterized by lava effusion and emissions of minor amounts of ash and steam, continued during 31 July-6 August. Although seismic activity decreased during 31 July-2 August, it still remained above background levels, and small discrete events continued to be detected. Cloud cover prevented satellite image and web-camera views. The Volcano Alert Level remained at Watch and the Aviation Color code remained at Orange.
Source: US Geological Survey Alaska Volcano Observatory (AVO)