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 25 July-31 July 2018
Name	Location	Eruption Start Date	Report Status
Ambae	Vanuatu	—	New
Ibu	Halmahera	2008 Apr 5	New
Krakatau	Sunda Strait	—	New
Rincon de la Vieja	Costa Rica	2021 Jun 28	New
Semeru	Eastern Java	2017 Jun 6	New
Sierra Negra	Isla Isabela (Galapagos)	—	New
Villarrica	Central Chile	2014 Dec 2 ± 7 days	New
Agung	Bali	—	Continuing
Aira	Kyushu (Japan)	2017 Mar 25	Continuing
Bagana	Bougainville (Papua New Guinea)	2000 Feb 28 (in or before)	Continuing
Cleveland	Chuginadak Island (USA)	—	Continuing
Dukono	Halmahera	1933 Aug 13	Continuing
Ebeko	Paramushir Island (Russia)	2022 Jun 11	Continuing
Fuego	South-Central Guatemala	2002 Jan 4	Continuing
Karymsky	Eastern Kamchatka (Russia)	—	Continuing
Kilauea	Hawaiian Islands (USA)	—	Continuing
Kirishimayama	Kyushu (Japan)	—	Continuing
Piton de la Fournaise	Reunion Island (France)	—	Continuing
Popocatepetl	Mexico	2005 Jan 9	Continuing
Rinjani	Lombok Island	—	Continuing
Sabancaya	Peru	2016 Nov 6	Continuing
Santa Maria	Southwestern Guatemala	1922 Jun 22	Continuing
Sheveluch	Central Kamchatka (Russia)	1999 Aug 15	Continuing
Turrialba	Costa Rica	—	Continuing

All times are local unless otherwise stated.

Ambae | 25 July-31 July 2018 | New Activity / Unrest Cite this Report

Ambae
Vanuatu

Vanuatu Meteorology and Geo-hazards Department (VMGD) reported that during overflights on 13 and 20 July, observers took photos of explosions at Ambae’s Lake Voui ejecting hot tephra from vents and producing ash plumes. Increased activity prompted VMGD to raise the Alert Level to 3 (on a scale of 0-5) on 21 July, and warn residents to stay at least 3 km away from the active crater. The report noted that current activity was similar to that in March, but with more sustained ash emissions. [Ash plumes continued over the next few days, and resulted in darkness during daytime on the 24th.] At about 2100 on 26 July explosions generated an ash cloud that rose as high as 12 km above the vent and spread NE, E, and SE. According to news articles, the event... prompted an order for an island-wide evacuation of the 10,000 residents. Another explosive event occurred early on 27 July. The Wellington VAAC reported sulfur dioxide emissions, and ash plumes rising to 2.4-4.6 km (8,000-15,000 ft) a.s.l. and drifting SE and NW. Pilots reported heavy ashfall over eastern Fiji. Smaller events producing ash-and-gas emissions continued throughout the day. On 1 August VMGD stated that the ashfall has had a significant impact on the island’s food and water supplies, and the health of the island residents.

Sources: Vanuatu Meteorology and Geohazards Department (VMGD), Wellington Volcanic Ash Advisory Center (VAAC), Radio New Zealand, Radio New Zealand

Ibu | 25 July-31 July 2018 | New Activity / Unrest Cite this Report

Ibu
Halmahera

PVMBG reported that at 1852 on 28 July an event at Ibu generated an ash plume that rose 5.5 km above the crater rim and drifted SE. An event at 1612 on 29 July produced an ash plume that rose 4.8 km and drifted N. Ash plumes later drifted SE. Seismic signals for both events were characterized by explosions and avalanches. The Alert Level remained at 2 (on a scale of 1-4), and the public was warned to stay at least 2 km away from the active crater, and 3.5 km away on the N side.

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

Krakatau | 25 July-31 July 2018 | New Activity / Unrest Cite this Report

Krakatau
Sunda Strait

Based on satellite and wind model data, the Darwin VAAC reported that during 25-26 July minor ash plumes from Anak Krakatau rose to an altitude of 1.2 km (4,000 ft) a.s.l. and drifted SW and NW. PVMBG noted that inclement weather conditions prevented views of the volcano during 27-30 July. The Alert Level remained at 2 (on a scale of 1-4); residents and visitors were warned not to approach the volcano within 1 km of the crater.

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

Rincon de la Vieja | 25 July-31 July 2018 | New Activity / Unrest Cite this Report

Rincon de la Vieja
Costa Rica

OVSICORI-UNA reported that a small explosion at Rincón de la Vieja was recorded at 1828 on 28 July, and was followed by tremor.

Source: Observatorio Vulcanologico y Sismologico de Costa Rica-Universidad Nacional (OVSICORI-UNA)

Semeru | 25 July-31 July 2018 | New Activity / Unrest Cite this Report

Semeru
Eastern Java

Based on analysis of satellite images, the Darwin VAAC reported that on 31 July an ash plume from Semeru rose to an altitude of 4.3 km (14,000 ft) a.s.l. and drifted W.

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Sierra Negra | 25 July-31 July 2018 | New Activity / Unrest Cite this Report

Sierra Negra
Isla Isabela (Galapagos)

IG reported that the eruption at Sierra Negra continued during 25-31 July. Sulfur dioxide flux was as high as about 1,400 tons per day (on 28 July), and daily counts of volcano-tectonic and long-period events were 24-65 and 3-32, respectively. Nightly incandescence from advancing lava flows was visible. Gas plumes rose more than 1.8 km above the vents and drifted N, NW, and W.

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

Villarrica | 25 July-31 July 2018 | New Activity / Unrest Cite this Report

Villarrica
Central Chile

POVI reported that on 24 July the vent in Villarrica’s summit crater was about 10-15 m in diameter and 90-100 m below the crater rim. Minor explosions and weak fumarolic emissions were noted. On 29 July a break in the cloud cover revealed more significant incandescence emanating from the summit than in the previous few days, and the largest thermal anomaly since August 2015 was identified in satellite images on 30 July. Ash and lapilli deposits on the E edge of the crater was also visible on 30 July.

Source: Proyecto Observación Villarrica Internet (POVI)

Agung | 25 July-31 July 2018 | Continuing ActivityCite this Report

Agung
Bali

According to PVMBG a ground-based observer reported that at 0041 on 25 July an event at Agung produced a dense ash-and-gas plume that rose 700 m and drifted E and SE. Seismic data recorded the event for two minutes and 15 seconds. At 1406 on 27 July an event lasting one minute and 32 seconds produced a dense ash-and-gas plume that rose 2 km and drifted W. The Alert Level remained at 3 (on a scale of 1-4) and the exclusion zone was stable at a 4-km radius.

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

Aira | 25 July-31 July 2018 | Continuing ActivityCite this Report

Aira
Kyushu (Japan)

JMA reported that there were four events and 11 explosions at Minamidake crater (at Aira Caldera’s Sakurajima volcano) during 23-30 July, with ash plumes rising as high as 2.5 km above the crater rim and material ejected as far as 1.3 km. Crater incandescence was sometimes visible at night. Sulfur dioxide emissions were 2,100 tons per day on 26 July. The Alert Level remained at 3 (on a 5-level scale).

Source: Japan Meteorological Agency (JMA)

Bagana | 25 July-31 July 2018 | Continuing ActivityCite this Report

Bagana
Bougainville (Papua New Guinea)

Based on analyses of satellite imagery and model data, the Darwin VAAC reported that during 29-30 July ash plumes from Bagana rose to altitudes of 1.8-2.1 km (6,000-7,000 ft) a.s.l. and drifted SW. A thermal anomaly was visible on 29 July.

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Cleveland | 25 July-31 July 2018 | Continuing ActivityCite this Report

Cleveland
Chuginadak Island (USA)

AVO reported that unrest at Cleveland continued during 25-31 July, though nothing significant was detected in seismic or infrasound data. Meteorological cloud cover prevented views of the crater on most days, though steaming from the crater was visible in satellite and webcam views during 25-26 July. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

Dukono | 25 July-31 July 2018 | Continuing ActivityCite this Report

Dukono
Halmahera

Based on PVMBG observations and satellite data, the Darwin VAAC reported that during 25-31 July ash plumes from Dukono rose to altitudes of 1.8-3.4 km (6,000-11,000 ft) a.s.l. and drifted N, NE, E, and S.

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Ebeko | 25 July-31 July 2018 | Continuing ActivityCite this Report

Ebeko
Paramushir Island (Russia)

Volcanologists in Severo-Kurilsk (Paramushir Island), about 7 km E of Ebeko, observed explosions during 20-21 and 25-26 July that sent ash plumes as high as 4 km (13,100 ft) a.s.l. An ash plume drifting about 15 km E was identified in satellite images on 20 July. The Aviation Color Code remained at Orange (the second highest level on a four-color scale).

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Fuego | 25 July-31 July 2018 | Continuing ActivityCite this Report

Fuego
South-Central Guatemala

INSIVUMEH reported that during 29-30 July avalanches of material descended the Cenizas drainage on Fuego’s SSW flank. Hot lahars generated by heavy rains on 30 July descended the Taniluyá (SW), Las Lajas (SE), El Jute (SE), and Cenizas drainages, carrying blocks 2-3 m in diameter and smelling of sulfur.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)

Karymsky | 25 July-31 July 2018 | Continuing ActivityCite this Report

Karymsky
Eastern Kamchatka (Russia)

KVERT reported that an ash cloud from Karymsky was identified in satellite images drifting 100 km SE on 20 July, and thermal anomalies were visible on 25 and 27 July. The Aviation Color Code remained at Orange (the second highest level on a four-color scale).

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Kilauea | 25 July-31 July 2018 | Continuing ActivityCite this Report

Kilauea
Hawaiian Islands (USA)

HVO reported that the eruption at Kilauea’s Lower East Rift Zone (LERZ) and within Halema`uma`u Crater continued during 18-24 July. Lava fountaining and spatter was concentrated at Fissure 8, feeding lava flows that continued to spread through Leilani Estates and Lanipuna Gardens subdivisions, and entered the ocean at Ahalanui.

Inward slumping of the crater rim and walls of Halema`uma`u continued, adjusting from the withdrawal of magma and subsidence of the summit area. Explosions from collapse events occurred about every other day (38.5 and 53.5 hours in between a few of the events). Sulfur dioxide emissions from the summit were very low.

Fountaining at Fissure 8 continued, producing Pele's hair and other volcanic glass that fell within Leilani Estates. The fountains continued to feed the lava flow that traveled NE, and then SSE, W of Kapoho Crater; lava occasionally overflowed the channel, and on 28 July ignited nearby vegetation. Small plumes of laze (a corrosive steam plume mixed with hydrochloric acid and fine volcanic glass particles) were generated at several points along a broad 2-km-wide flow front at Ahalanui. The westernmost edge was less than 175 m NE of the boat ramp in Isaac Hale Park (by 30 July).

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Kirishimayama | 25 July-31 July 2018 | Continuing ActivityCite this Report

Kirishimayama
Kyushu (Japan)

JMA reported that during 23-30 July white fumarolic plumes rose 300-500 m above a vent on the S side of Iwo-yama (also called Ioyama, NW flank of Karakuni-dake), a stratovolcano of the Kirishimayama volcano group. A hot pool of water was visible on the S side, and muddy water flowed down the W side. The Alert Level remained at 3 (on a scale of 1-5).

Source: Japan Meteorological Agency (JMA)

Piton de la Fournaise | 25 July-31 July 2018 | Continuing ActivityCite this Report

Piton de la Fournaise
Reunion Island (France)

OVPF reported that inflation at Piton de la Fournaise resumed after 13 July, the end of the last eruption. A period if increased seismicity was detected on 26 July, with 32 volcano-tectonic events less than 2 km deep being recorded during 0400-1600; 23 of those events were detected during 1200-1300.

Source: Observatoire Volcanologique du Piton de la Fournaise (OVPF)

Popocatepetl | 25 July-31 July 2018 | Continuing ActivityCite this Report

Popocatepetl
Mexico

CENAPRED reported that each day during 25-31 July there were 24-42 steam-and-gas emissions from Popocatépetl, and nightly crater incandescence. Explosions were detected almost every day: five on 26 July; nine on 27 July; one on 28 July; three on 30 July. A series of gas-and-ash emissions began at 0307 on 31 July and lasted for 215 minutes. Ejected incandescent tephra landed on the flanks. The gas-and-ash plumes rose 2 km above the crater rim and drifted WSW, causing ashfall in Tetela del Volcán, Yecapixtla, Tlalnepantla, and Totolapan (Morelos state), and in Amecameca, Acuautla, Ecatzingo, Ozumba, and Tepetlixpa (Mexico state). The Alert Level remained at Yellow, Phase Two.

Source: Centro Nacional de Prevencion de Desastres (CENAPRED)

Rinjani | 25 July-31 July 2018 | Continuing ActivityCite this Report

Rinjani
Lombok Island

PVMBG and BNPB reported that a M 6.4 earthquake was recorded at 0547 on 29 July, shaking the islands of Lombok, Bali, and Sumbawa, and causing significant damage to buildings (including collapses) and roads, ground cracks, multiple injuries, and the death of 17 people in Lombok. The hypocenter was 24 km deep, and 47 km NE of Mataram City. Aftershocks were numerous and as large as M 5.7. The earthquakes caused remobilization of ash deposits on Rinjani as well as landslides. There were 1,226 visitors to the Mount Rinjani National Park Area at the time, and, according to news articles, about 690 climbers were on the volcano and had to be rescued. One person in the national park died from rockfalls. The Alert Level remained at 2 (on a scale of 1-4); the public was warned not to approach the crater within a 1.5-km radius.

Sources: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM), Badan Nacional Penanggulangan Bencana (BNPB), The Jakarta Post, Reuters

Sabancaya | 25 July-31 July 2018 | Continuing ActivityCite this Report

Sabancaya
Peru

Observatorio Vulcanológico del Sur del IGP (OVS-IGP) and Observatorio Vulcanológico del INGEMMET (OVI) reported that explosions at Sabancaya averaged 19 per day during 23-29 July. Hybrid earthquakes were infrequent and low magnitude. Gas-and-ash plumes rose as high as 3 km above the crater rim and drifted 40 km SE and E. On 26 July the sulfur dioxide gas flux was high at 4,195 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)

Santa Maria | 25 July-31 July 2018 | Continuing ActivityCite this Report

Santa Maria
Southwestern Guatemala

INSIVUMEH reported that during 28-30 July explosions at Santa María's Santiaguito lava-dome complex generated white plumes that rose 600-800 m and drifted SW. Avalanches of material descended the NW, E, and SE flanks of the lava dome.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)

Sheveluch | 25 July-31 July 2018 | Continuing ActivityCite this Report

Sheveluch
Central Kamchatka (Russia)

KVERT reported that satellite images showed a weak thermal anomaly over Sheveluch during 19 and 21-22 July. The Aviation Color Code remained at Orange (the second highest level on a four-color scale).

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Turrialba | 25 July-31 July 2018 | Continuing ActivityCite this Report

Turrialba
Costa Rica

OVSICORI-UNA reported that during 23-31 July activity at Turrialba was characterized by sporadic, passive gas-and-ash emissions detected almost daily. The plumes rose no higher than 300 m above the vent rim, and drifted NW, W, and SW. Ashfall was reported in several neighborhoods in the Valle Central, including Coronado, Tibás (35 km WSW), Goicoechea (28 km WSW), and Moravia (31 km WSW) on 24 July, and in Tres Ríos (27 km SW) on 31 July. A sulfur odor was occasionally reported.

Source: Observatorio Vulcanologico y Sismologico de Costa Rica-Universidad Nacional (OVSICORI-UNA)

Weekly Reports Archive

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

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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.

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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.

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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 Ambae
Vanuatu Meteorology and Geo-hazards Department (VMGD) reported that during overflights on 13 and 20 July, observers took photos of explosions at Ambae’s Lake Voui ejecting hot tephra from vents and producing ash plumes. Increased activity prompted VMGD to raise the Alert Level to 3 (on a scale of 0-5) on 21 July, and warn residents to stay at least 3 km away from the active crater. The report noted that current activity was similar to that in March, but with more sustained ash emissions. [Ash plumes continued over the next few days, and resulted in darkness during daytime on the 24th.] At about 2100 on 26 July explosions generated an ash cloud that rose as high as 12 km above the vent and spread NE, E, and SE. According to news articles, the event... prompted an order for an island-wide evacuation of the 10,000 residents. Another explosive event occurred early on 27 July. The Wellington VAAC reported sulfur dioxide emissions, and ash plumes rising to 2.4-4.6 km (8,000-15,000 ft) a.s.l. and drifting SE and NW. Pilots reported heavy ashfall over eastern Fiji. Smaller events producing ash-and-gas emissions continued throughout the day. On 1 August VMGD stated that the ashfall has had a significant impact on the island’s food and water supplies, and the health of the island residents.
Sources: Vanuatu Meteorology and Geohazards Department (VMGD), Wellington Volcanic Ash Advisory Center (VAAC), Radio New Zealand, Radio New Zealand

Report for Ibu
PVMBG reported that at 1852 on 28 July an event at Ibu generated an ash plume that rose 5.5 km above the crater rim and drifted SE. An event at 1612 on 29 July produced an ash plume that rose 4.8 km and drifted N. Ash plumes later drifted SE. Seismic signals for both events were characterized by explosions and avalanches. The Alert Level remained at 2 (on a scale of 1-4), and the public was warned to stay at least 2 km away from the active crater, and 3.5 km away on the N side.
Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)

Report for Krakatau
Based on satellite and wind model data, the Darwin VAAC reported that during 25-26 July minor ash plumes from Anak Krakatau rose to an altitude of 1.2 km (4,000 ft) a.s.l. and drifted SW and NW. PVMBG noted that inclement weather conditions prevented views of the volcano during 27-30 July. The Alert Level remained at 2 (on a scale of 1-4); residents and visitors were warned not to approach the volcano within 1 km of the crater.
Sources: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM), Darwin Volcanic Ash Advisory Centre (VAAC)

Report for Rincon de la Vieja
OVSICORI-UNA reported that a small explosion at Rincón de la Vieja was recorded at 1828 on 28 July, and was followed by tremor.
Source: Observatorio Vulcanologico y Sismologico de Costa Rica-Universidad Nacional (OVSICORI-UNA)

Report for Semeru
Based on analysis of satellite images, the Darwin VAAC reported that on 31 July an ash plume from Semeru 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 Sierra Negra
IG reported that the eruption at Sierra Negra continued during 25-31 July. Sulfur dioxide flux was as high as about 1,400 tons per day (on 28 July), and daily counts of volcano-tectonic and long-period events were 24-65 and 3-32, respectively. Nightly incandescence from advancing lava flows was visible. Gas plumes rose more than 1.8 km above the vents and drifted N, NW, and W.
Source: Instituto Geofísico-Escuela Politécnica Nacional (IG-EPN)

Report for Villarrica
POVI reported that on 24 July the vent in Villarrica’s summit crater was about 10-15 m in diameter and 90-100 m below the crater rim. Minor explosions and weak fumarolic emissions were noted. On 29 July a break in the cloud cover revealed more significant incandescence emanating from the summit than in the previous few days, and the largest thermal anomaly since August 2015 was identified in satellite images on 30 July. Ash and lapilli deposits on the E edge of the crater was also visible on 30 July.
Source: Proyecto Observación Villarrica Internet (POVI)

Report for Agung
According to PVMBG a ground-based observer reported that at 0041 on 25 July an event at Agung produced a dense ash-and-gas plume that rose 700 m and drifted E and SE. Seismic data recorded the event for two minutes and 15 seconds. At 1406 on 27 July an event lasting one minute and 32 seconds produced a dense ash-and-gas plume that rose 2 km and drifted W. The Alert Level remained at 3 (on a scale of 1-4) and the exclusion zone was stable at a 4-km radius.
Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)

Report for Aira
JMA reported that there were four events and 11 explosions at Minamidake crater (at Aira Caldera’s Sakurajima volcano) during 23-30 July, with ash plumes rising as high as 2.5 km above the crater rim and material ejected as far as 1.3 km. Crater incandescence was sometimes visible at night. Sulfur dioxide emissions were 2,100 tons per day on 26 July. The Alert Level remained at 3 (on a 5-level scale).
Source: Japan Meteorological Agency (JMA)

Report for Bagana
Based on analyses of satellite imagery and model data, the Darwin VAAC reported that during 29-30 July ash plumes from Bagana rose to altitudes of 1.8-2.1 km (6,000-7,000 ft) a.s.l. and drifted SW. A thermal anomaly was visible on 29 July.
Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Report for Cleveland
AVO reported that unrest at Cleveland continued during 25-31 July, though nothing significant was detected in seismic or infrasound data. Meteorological cloud cover prevented views of the crater on most days, though steaming from the crater was visible in satellite and webcam views during 25-26 July. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.
Source: US Geological Survey Alaska Volcano Observatory (AVO)

Report for Dukono
Based on PVMBG observations and satellite data, the Darwin VAAC reported that during 25-31 July ash plumes from Dukono rose to altitudes of 1.8-3.4 km (6,000-11,000 ft) a.s.l. and drifted N, NE, E, and S.
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 20-21 and 25-26 July that sent ash plumes as high as 4 km (13,100 ft) a.s.l. An ash plume drifting about 15 km E was identified in satellite images on 20 July. 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 during 29-30 July avalanches of material descended the Cenizas drainage on Fuego’s SSW flank. Hot lahars generated by heavy rains on 30 July descended the Taniluyá (SW), Las Lajas (SE), El Jute (SE), and Cenizas drainages, carrying blocks 2-3 m in diameter and smelling of sulfur.
Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)

Report for Karymsky
KVERT reported that an ash cloud from Karymsky was identified in satellite images drifting 100 km SE on 20 July, and thermal anomalies were visible on 25 and 27 July. 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 that the eruption at Kilauea’s Lower East Rift Zone (LERZ) and within Halema`uma`u Crater continued during 18-24 July. Lava fountaining and spatter was concentrated at Fissure 8, feeding lava flows that continued to spread through Leilani Estates and Lanipuna Gardens subdivisions, and entered the ocean at Ahalanui.

Inward slumping of the crater rim and walls of Halema`uma`u continued, adjusting from the withdrawal of magma and subsidence of the summit area. Explosions from collapse events occurred about every other day (38.5 and 53.5 hours in between a few of the events). Sulfur dioxide emissions from the summit were very low.

Fountaining at Fissure 8 continued, producing Pele's hair and other volcanic glass that fell within Leilani Estates. The fountains continued to feed the lava flow that traveled NE, and then SSE, W of Kapoho Crater; lava occasionally overflowed the channel, and on 28 July ignited nearby vegetation. Small plumes of laze (a corrosive steam plume mixed with hydrochloric acid and fine volcanic glass particles) were generated at several points along a broad 2-km-wide flow front at Ahalanui. The westernmost edge was less than 175 m NE of the boat ramp in Isaac Hale Park (by 30 July).
Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Report for Kirishimayama
JMA reported that during 23-30 July white fumarolic plumes rose 300-500 m above a vent on the S side of Iwo-yama (also called Ioyama, NW flank of Karakuni-dake), a stratovolcano of the Kirishimayama volcano group. A hot pool of water was visible on the S side, and muddy water flowed down the W side. The Alert Level remained at 3 (on a scale of 1-5).
Source: Japan Meteorological Agency (JMA)

Report for Piton de la Fournaise
OVPF reported that inflation at Piton de la Fournaise resumed after 13 July, the end of the last eruption. A period if increased seismicity was detected on 26 July, with 32 volcano-tectonic events less than 2 km deep being recorded during 0400-1600; 23 of those events were detected during 1200-1300.
Source: Observatoire Volcanologique du Piton de la Fournaise (OVPF)

Report for Popocatepetl
CENAPRED reported that each day during 25-31 July there were 24-42 steam-and-gas emissions from Popocatépetl, and nightly crater incandescence. Explosions were detected almost every day: five on 26 July; nine on 27 July; one on 28 July; three on 30 July. A series of gas-and-ash emissions began at 0307 on 31 July and lasted for 215 minutes. Ejected incandescent tephra landed on the flanks. The gas-and-ash plumes rose 2 km above the crater rim and drifted WSW, causing ashfall in Tetela del Volcán, Yecapixtla, Tlalnepantla, and Totolapan (Morelos state), and in Amecameca, Acuautla, Ecatzingo, Ozumba, and Tepetlixpa (Mexico state). The Alert Level remained at Yellow, Phase Two.
Source: Centro Nacional de Prevencion de Desastres (CENAPRED)

Report for Rinjani
PVMBG and BNPB reported that a M 6.4 earthquake was recorded at 0547 on 29 July, shaking the islands of Lombok, Bali, and Sumbawa, and causing significant damage to buildings (including collapses) and roads, ground cracks, multiple injuries, and the death of 17 people in Lombok. The hypocenter was 24 km deep, and 47 km NE of Mataram City. Aftershocks were numerous and as large as M 5.7. The earthquakes caused remobilization of ash deposits on Rinjani as well as landslides. There were 1,226 visitors to the Mount Rinjani National Park Area at the time, and, according to news articles, about 690 climbers were on the volcano and had to be rescued. One person in the national park died from rockfalls. The Alert Level remained at 2 (on a scale of 1-4); the public was warned not to approach the crater within a 1.5-km radius.
Sources: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM), Badan Nacional Penanggulangan Bencana (BNPB), The Jakarta Post, Reuters

Report for Sabancaya
Observatorio Vulcanológico del Sur del IGP (OVS-IGP) and Observatorio Vulcanológico del INGEMMET (OVI) reported that explosions at Sabancaya averaged 19 per day during 23-29 July. Hybrid earthquakes were infrequent and low magnitude. Gas-and-ash plumes rose as high as 3 km above the crater rim and drifted 40 km SE and E. On 26 July the sulfur dioxide gas flux was high at 4,195 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 Santa Maria
INSIVUMEH reported that during 28-30 July explosions at Santa María's Santiaguito lava-dome complex generated white plumes that rose 600-800 m and drifted SW. Avalanches of material descended the NW, E, and SE flanks of the lava dome.
Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)

Report for Sheveluch
KVERT reported that satellite images showed a weak thermal anomaly over Sheveluch during 19 and 21-22 July. 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 Turrialba
OVSICORI-UNA reported that during 23-31 July activity at Turrialba was characterized by sporadic, passive gas-and-ash emissions detected almost daily. The plumes rose no higher than 300 m above the vent rim, and drifted NW, W, and SW. Ashfall was reported in several neighborhoods in the Valle Central, including Coronado, Tibás (35 km WSW), Goicoechea (28 km WSW), and Moravia (31 km WSW) on 24 July, and in Tres Ríos (27 km SW) on 31 July. A sulfur odor was occasionally reported.
Source: Observatorio Vulcanologico y Sismologico de Costa Rica-Universidad Nacional (OVSICORI-UNA)