Smithsonian / USGS Weekly Volcanic Activity Report

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 2019
Name	Country	Volcanic Province	Eruption Start Date	Report Status
Awu	Indonesia	Sangihe Volcanic Arc	—	New
Karangetang	Indonesia	Sangihe Volcanic Arc	—	New
Semisopochnoi	United States	Aleutian Ridge Volcanic Arc	—	New
Shishaldin	United States	Aleutian Ridge Volcanic Arc	—	New
Tangkuban Parahu	Indonesia	Sunda Volcanic Arc	—	New
Ulawun	Papua New Guinea	Bismarck Volcanic Arc	—	New
Veniaminof	United States	Aleutian Ridge Volcanic Arc	—	New
Aira	Japan	Ryukyu Volcanic Arc	2017 Mar 25	Continuing
Asosan	Japan	Nankai Volcanic Arc	—	Continuing
Chiles-Cerro Negro	Colombia-Ecuador	Andean Northern Volcanic Arc	—	Continuing
Dukono	Indonesia	Halmahera Volcanic Arc	1933 Aug 13	Continuing
Ebeko	Russia	Kuril Volcanic Arc	2022 Jun 11	Continuing
Etna	Italy	Sicily Volcanic Province	—	Continuing
Karymsky	Russia	Eastern Kamchatka Volcanic Arc	—	Continuing
Kerinci	Indonesia	Sunda Volcanic Arc	—	Continuing
Klyuchevskoy	Russia	Eastern Kamchatka Volcanic Arc	—	Continuing
Krakatau	Indonesia	Sunda Volcanic Arc	—	Continuing
Merapi	Indonesia	Sunda Volcanic Arc	2020 Dec 31	Continuing
Nevados de Chillan	Chile	Andean Southern Volcanic Arc	—	Continuing
Nyamulagira	DR Congo	Albertine Rift Zone	2018 Apr 18	Continuing
Nyiragongo	DR Congo	Albertine Rift Zone	2002 May 17 (?)	Continuing
Sabancaya	Peru	Andean Central Volcanic Arc	2016 Nov 6	Continuing
Sangeang Api	Indonesia	Sunda Volcanic Arc	—	Continuing
Sheveluch	Russia	Eastern Kamchatka Volcanic Arc	1999 Aug 15	Continuing
Suwanosejima	Japan	Ryukyu Volcanic Arc	2004 Oct 23	Continuing
Villarrica	Chile	Andean Southern Volcanic Arc	2014 Dec 2 ± 7 days	Continuing

All times are local unless otherwise stated.

Awu (Indonesia) | 31 July-6 August 2019 | New Activity / Unrest Cite this Report

Awu
Sangihe Volcanic Arc

The Darwin VAAC reported that on 4 August an ash plume from Awu was visible in satellite images rising to an altitude of 1.8 km (6,000 ft) a.s.l. and drifting N.

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Karangetang (Indonesia) | 31 July-6 August 2019 | New Activity / Unrest Cite this Report

Karangetang
Sangihe Volcanic Arc

PVMBG reported that beginning at 1858 on 20 July incandescent avalanches of material from Karangetang’s Main Crater traveled as far as 1 km W down the Pangi and Kinali drainages. By 22 July incandescent material had traveled another 500 m down the same drainages, and 1 km down the Nanitu and Beha drainages. Based on analyses of satellite imagery and model data, the Darwin VAAC reported that during 30-31 July intermittent discrete ash plumes rose to an altitude of 7.6 km (25,000 ft) a.s.l. and drifted W, and continuous ash emissions rose to 3 km (10,000 ft) a.s.l. A thermal anomaly was visible. On 5 August ash plumes rose to 3 km (10,000 ft) a.s.l. and drifted E; a thermal anomaly was again visible. The Alert Level remained at 2 (on a scale of 1-4).

Sources: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM), Darwin Volcanic Ash Advisory Centre (VAAC)

Semisopochnoi (United States) | 31 July-6 August 2019 | New Activity / Unrest Cite this Report

Semisopochnoi
Aleutian Ridge Volcanic Arc

AVO reported that during 31 July-6 August seismicity at Semisopochnoi remained elevated and was characterized by periods of weak, continuous tremor and discrete low-frequency earthquakes. Satellite images were mostly cloudy, though a possible steam plume was visible during 5-6 August. The Volcano Alert Level remained at Watch and the Aviation Color Code remained at Orange.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

Shishaldin (United States) | 31 July-6 August 2019 | New Activity / Unrest Cite this Report

Shishaldin
Aleutian Ridge Volcanic Arc

AVO reported that satellite images of Shishaldin acquired on 28 July showed a small spatter cone with lava flows in the summit crater. During 31 July-6 August continuous weak tremor was recorded by the seismic network and elevated surface temperatures were sometimes visible in satellite images. A small steam plume was observed in a few satellite and web camera images. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

Tangkuban Parahu (Indonesia) | 31 July-6 August 2019 | New Activity / Unrest Cite this Report

Tangkuban Parahu
Sunda Volcanic Arc

PVMBG reported that an eruption at Tangkubanparahu's Ratu Crater, recorded at 2046 on 1 August, generated a dense black ash-and-sediment-laden plume that rose about 180 m from the bottom of the crater, and light-colored ash plumes mixed with water vapor that rose 200 m and drifted N and NE. The event lasted 11 minutes and 23 seconds based on seismic data. Ash and sediment fell in areas around the crater. Four eruptive events were recorded during the morning of 2 August, though ash emissions were not visually observed. The Alert Level was raised to 2 (on a scale of 1-4). A period of continuous ash emissions was recorded during 2-4 August.

Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)

Ulawun (Papua New Guinea) | 31 July-6 August 2019 | New Activity / Unrest Cite this Report

Ulawun
Bismarck Volcanic Arc

RVO reported that during 1-2 August white-to-grayish vapor plumes rose from Ulawun’s summit crater and drifted NW. Incandescence from the summit crater was visible at night and jetting noises were audible for a short interval. RSAM values fluctuated but peaked at high levels. During the night of 2-3 August crater incandescence strengthened and roaring noises became louder around 0400. An eruption began between 0430 and 0500 on 3 August; booming noises commenced around 0445. By 0600 dense light-gray ash emissions were drifting NW, causing ashfall in areas downwind including Ulamona Mission. Ash emissions continued through the day and grew from light to dark gray with time. The eruption intensified at 1900 and a lava fountain rose more than 100 m above the crater rim. A Plinian ash plume rose 19 km and drifted W and SW, causing ashfall in areas downwind such as Navo and Kabaya, and as far as Kimbe Town. The Darwin VAAC reported that the ash plume expanded radially and reached the stratosphere, rising to 19.2 km (63,000 ft) a.s.l. The plume then detached and drifted S and then SE.

The Alert Level was raised to Stage 3 (the second highest level on a four-stage scale). The areas most affected by ash and scoria fall were between Navo (W) and Saltamana Estate (NW). Two classrooms at the Navo Primary School and a church in Navo collapsed from the weight of the ash and scoria; one of the classroom roofs had already partially collapsed during the 26 June eruption. Evacuees in tents as a result of the 26 June eruption reported damage. Rabaul town (E) also reported ashfall. Seismicity declined rapidly within two hours of the event, though continued to fluctuate at moderate levels. According to a news source flights in and out of Hoskins airport in Port Moresby were cancelled on 4 August due to tephra fall. The Alert Level was lowered to Stage 1. Small amounts of white and gray vapor were emitted from the summit crater during 4-6 August.

Sources: Rabaul Volcano Observatory (RVO), Darwin Volcanic Ash Advisory Centre (VAAC), Radio New Zealand, Papua New Guinea Post-Courier Online

Veniaminof (United States) | 31 July-6 August 2019 | New Activity / Unrest Cite this Report

Veniaminof
Aleutian Ridge Volcanic Arc

Low-level tremor at Veniaminof coincided with a pilot observation of a steam plume at 1230 on 1 August, prompting AVO to raise the Aviation Color Code to Yellow and the Volcano Alert Level to Advisory. On 2 August AVO noted that tremor had subsided, though low-level seismicity persisted at least through 6 August. Elevated surface temperatures were visible in satellite images. A small steam plume was also visible on 3 August.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

Aira (Japan) | 31 July-6 August 2019 | Continuing ActivityCite this Report

Aira
Ryukyu Volcanic Arc

JMA reported that during 30 July-5 August very small eruptive events were detected at Minamidake crater (at Aira Caldera’s Sakurajima volcano), though none of them were explosive. Crater incandescence was occasionally visible in webcams at night. The Alert Level remained at 3 (on a 5-level scale).

Source: Japan Meteorological Agency (JMA)

Asosan (Japan) | 31 July-6 August 2019 | Continuing ActivityCite this Report

Asosan
Nankai Volcanic Arc

JMA reported that increased eruptive activity at Asosan that began on 28 July continued at least through 5 August. Volcanologists confirmed that high-temperature, gray-white plumes rose from the center of Nakadake Crater during fieldwork conducted on 31 July. Grayish white plumes rose 1.3 km and 1.5 km above the crater rim on 1 and 5 August, respectively. Incandescence from the crater was visible at night. The Alert Level remained at 2 (on a scale of 1-5).

Source: Japan Meteorological Agency (JMA)

Chiles-Cerro Negro (Colombia-Ecuador) | 31 July-6 August 2019 | Continuing ActivityCite this Report

Chiles-Cerro Negro
Andean Northern Volcanic Arc

Instituto Geofísico de la Escuela Politécnica Nacional (IGEPN) and the Observatorio Vulcanológico y Sismológico de Pasto del Servicio Geológico Colombiano (SGC OVSP) jointly reported that the most recent seismic swarm below Cerro Negro de Mayasquer and Chiles volcanoes began in September 2018 and continued at least through 1 August. The swarm has consisted of 147,000 earthquakes, recorded up to the time of the report publication, mostly with magnitudes less than 3.6. Notably, at least 91 very-long-period earthquakes and 89 long-period earthquakes have been detected, indicative of a magmatic body at depth. In addition, at 0738 on 25 July a M4 earthquake was located 4 km below the summit of Chiles and felt by residents. About 850 volcano-tectonic events were recorded during 25-28 July.

Source: Instituto Geofísico-Escuela Politécnica Nacional (IG-EPN)

Dukono (Indonesia) | 31 July-6 August 2019 | Continuing ActivityCite this Report

Dukono
Halmahera Volcanic Arc

Based on satellite and wind model data, the Darwin VAAC reported that during 31 July-6 August ash plumes from Dukono rose to an altitude of 1.8 km (6,000 ft) a.s.l. and drifted mainly N and NE. The Alert Level remained at 2 (on a scale of 1-4), and the public was warned to remain outside of the 2-km exclusion zone.

Sources: Darwin Volcanic Ash Advisory Centre (VAAC), Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)

Ebeko (Russia) | 31 July-6 August 2019 | Continuing ActivityCite this Report

Ebeko
Kuril Volcanic Arc

Volcanologists in Severo-Kurilsk (Paramushir Island), about 7 km E of Ebeko, observed explosions during 25-26 and 29 July, and 1 August, that sent ash plumes up to 2.5 km (8,200 ft) a.s.l. The plumes drifted in multiple directions. The Aviation Color Code remained at Orange (the second highest level on a four-color scale).

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Etna (Italy) | 31 July-6 August 2019 | Continuing ActivityCite this Report

Etna
Sicily Volcanic Province

INGV reported that on 25 July Etna’s New Southeast Crater (NSEC) periodically emitted gas and ash. At 0630 on 27 July the seismic network detected a sudden increase in tremor amplitude, and at 0915 a new fissure opened on the S flank of NSEC. Explosive activity at the crater intensified at 1020 and a dense, ash-rich plume rose to 4.5-5 km a.s.l. and drifted E. A thin layer of ash was deposited in Giarre, Riposto and Torre Archirafi. Lava emerged from the S part of the new fissure and traveled SW and S; by 1235 the longest part of the flow had reached 2,850 m elevation and by 1330 it had reached 2,600 m elevation. Beginning at 1321 a sequence of particularly strong explosions generated ash plumes that rose as high as 7.5 km a.s.l. Explosive activity decreased around 0440 on 28 July, and lava effused from the vent at a lower rate. Starting at 0846 the Northeast Crater (NEC) occasionally emitted small plumes of red-brown ash. Explosive and effusive activity at NSEC ceased that evening. Activity during 29 July-4 August consisted of a few episodes of ash emissions at Bocca Nuova Crater and NEC.

Source: Sezione di Catania - Osservatorio Etneo (INGV)

Karymsky (Russia) | 31 July-6 August 2019 | Continuing ActivityCite this Report

Karymsky
Eastern Kamchatka Volcanic Arc

KVERT reported that on 26 July a thermal anomaly over Karymsky was visible in satellite images along with an ash plume drifting 60 km SE. The Aviation Color Code remained at Orange (the second highest level on a four-color scale).

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Kerinci (Indonesia) | 31 July-6 August 2019 | Continuing ActivityCite this Report

Kerinci
Sunda Volcanic Arc

PVMBG reported that at 1248 on 31 July a gray ash emission from Kerinci rose around 800 m above the summit and drifted E and NE according to a ground observer. The Alert Level remained at 2 (on a scale of 1-4), and the public was warned to remain outside of the 3-km exclusion zone.

Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)

Klyuchevskoy (Russia) | 31 July-6 August 2019 | Continuing ActivityCite this Report

Klyuchevskoy
Eastern Kamchatka Volcanic Arc

KVERT reported that a weak thermal anomaly over Klyuchevskoy was visible in satellite images during 26, 29, and 31 July, and 1 August. An ash emission was visible in webcam images on 1 August. The Aviation Color Code remained at Orange (the second highest level on a four-color scale).

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Krakatau (Indonesia) | 31 July-6 August 2019 | Continuing ActivityCite this Report

Krakatau
Sunda Volcanic Arc

PVMBG reported that Anak Krakatau’s seismic network recorded 10 eruptive events during 29 July-4 August. The events were not followed by visible emissions, though observations were hindered by weather conditions. The Alert Level remained at 2 (on a scale of 1-4), and the public was warned to remain outside of the 2-km radius hazard zone from the crater.

Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)

Merapi (Indonesia) | 31 July-6 August 2019 | Continuing ActivityCite this Report

Merapi
Sunda Volcanic Arc

PVMBG reported that during 29 July-4 August the lava-dome volume at Merapi did not change and was an estimated 475,000 cubic meters, based on analyses of drone images. Extruded lava fell into the upper parts of the SE-flank, generating a total of four block-and-ash flows that traveled as far as 1 km down the Gendol drainage on 31 July and 4 August. Diffuse white plumes rose as high as 50 m above the summit on some days. The Alert Level remained at 2 (on a scale of 1-4), and residents were warned to stay outside of the 3-km exclusion zone.

Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)

Nevados de Chillan (Chile) | 31 July-6 August 2019 | Continuing ActivityCite this Report

Nevados de Chillan
Andean Southern Volcanic Arc

On 6 August ONEMI and SERNAGEOMIN reported that activity at Nevados de Chillán’s Nicanor Crater increased in the previous few days, characterized by an increase in the size and occurrence of explosions. Specifically, there were 129 explosive events recorded since 3 August. Dense gas-and-ash plumes rose as high as 1.6 km above the crater rim and ejected material onto the flanks. Crater incandescence was visible at night. A lahar traveled 1.5 km NNE. The Alert Level remained at Orange, the second highest level on a four-color scale, and residents were reminded not to approach the crater within 3 km. ONEMI maintained an Alert Level Yellow (the middle level on a three-color scale) for the communities of Pinto, Coihueco, and San Fabián.

Sources: Oficina Nacional de Emergencia-Ministerio del Interior (ONEMI), Servicio Nacional de Geología y Minería (SERNAGEOMIN)

Nyamulagira (DR Congo) | 31 July-6 August 2019 | Continuing ActivityCite this Report

Nyamulagira
Albertine Rift Zone

The Observatoire Volcanologique de Goma (OVG) reported that collapses of Nyamuragira’s inner crater walls observed in May 2019 continued during 1-31 July. Lava fountaining from a small cone was visible.

Source: Observatoire Volcanologique de Goma (OVG)

Nyiragongo (DR Congo) | 31 July-6 August 2019 | Continuing ActivityCite this Report

Nyiragongo
Albertine Rift Zone

The Observatoire Volcanologique de Goma (OVG) reported that during 1-31 July the level Nyiragongo’s lava lake had dropped, making it not visible in the daytime. Incandescence from the lake continued to be visible at night. Activity also declined at a small eruptive cone that formed in the crater in 2014.

Source: Observatoire Volcanologique de Goma (OVG)

Sabancaya (Peru) | 31 July-6 August 2019 | Continuing ActivityCite this Report

Sabancaya
Andean Central Volcanic Arc

Instituto Geofísico del Perú (IGP) reported that an average of 13 low-to-medium intensity explosions per day occurred at Sabancaya during 22-28 July. Gas-and-ash plumes rose as high as 2.3 km above the crater rim and drifted NE, E, and SE. There were eight thermal anomalies identified in satellite data. The report noted that the public should not approach the crater within a 12-km radius. Single explosions on 1 and 5 August produced an ash plume that drifted more than 30 km E and W, respectively.

Source: Instituto Geofísico del Perú (IGP)

Sangeang Api (Indonesia) | 31 July-6 August 2019 | Continuing ActivityCite this Report

Sangeang Api
Sunda Volcanic Arc

The Darwin VAAC reported that during 31 July-3 August ash plumes from Sangeang Api were identified in satellite images rising to 2.4-3 km (8,000-10,000 ft) a.s.l. and drifting in multiple directions. The Alert Level remained at 2 (on a scale of 1-4).

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Sheveluch (Russia) | 31 July-6 August 2019 | Continuing ActivityCite this Report

Sheveluch
Eastern Kamchatka Volcanic Arc

KVERT reported that a thermal anomaly over Sheveluch’s lava dome was identified daily in satellite images during 26 July-2 August. The Aviation Color Code remained at Orange (the second highest level on a four-color scale).

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Suwanosejima (Japan) | 31 July-6 August 2019 | Continuing ActivityCite this Report

Suwanosejima
Ryukyu Volcanic Arc

JMA reported that at 2331 on 1 August an explosion at Suwanosejima’s Ontake Crater ejected blocks 400 m from the crater. Weather clouds prevented visual confirmation of an ash plume. Crater incandescence was sometimes visible at night. The number of volcanic earthquakes increased on 4 August and four explosions were recorded on 5 August. The Alert Level remained at 2 (on a 5-level scale).

Source: Japan Meteorological Agency (JMA)

Villarrica (Chile) | 31 July-6 August 2019 | Continuing ActivityCite this Report

Villarrica
Andean Southern Volcanic Arc

ONEMI and SERNAGEOMIN reported that on 6 August the Alert Level for Villarrica was raised to Yellow, the second lowest level on a four-color scale, reflecting the recent increase in minor Strombolian activity ejecting spatter onto the flanks near the rim during the past weeks.

Sources: Oficina Nacional de Emergencia-Ministerio del Interior (ONEMI), Servicio Nacional de Geología y Minería (SERNAGEOMIN)

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Criteria & Disclaimers

Criteria

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

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

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

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

Disclaimers

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

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

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

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