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 Thursday, these notices are preliminary and subject to change as events are studied in more detail. This is not a comprehensive list of eruptions during the week, but rather a summary of activity that meet selected criteria. Carefully reviewed, detailed reports are published in the Bulletin of the Global Volcanism Network.

The Sezione di Catania - Osservatorio Etneo (INGV) reported eruptive activity at Etna?s summit craters during 29 June-5 July characterized by lava effusion from two vents, Strombolian activity at Voragine Crater (VOR), and activity at a new fissure between VOR and Northeast Crater (NEC). Lava that began to effuse on 29 June from a vent on the E base of VOR, at 3,030 elevation, continued into July. INGV staff conducted a field survey on 2 July and observed that the lava flow field was active and complex, characterized by superimposed lava flows, ephemeral vents, and small lava tubes. Later that evening a small lava flow effused from a new vent, located between VOR and NEC at around 3,200 m elevation, and traveled 150 m before stopping the next morning on 3 July. The staff also observed that Strombolian activity from a pit crater on the upper E flank of VOR that began overnight during 26-27 June was continuing and intensified during 2-4 July. The flow from the vent on the E base of VOR became less active and stopped on 4 July. The lava-flow field was about 1.2 km long, with the most advanced lava flow reaching about 2,605 elevation, and about 87,000 square meters in size, based on drone photos from 2 July and a 5 July satellite image. On 5 July intense explosive activity began at several vents that formed along a new fissure that extended NNE from VOR to the NEC. Vents along the higher elevations of the fissure continuously produced ash while lower vents produced Strombolian activity. Ash plumes rose about 4.5 km a.s.l. and drifted mainly S, causing ashfall in several municipalities on the S flank, in the area between Rifugio Sapienza (5 km S) and Catania (around 29 km SSE), and the temporary closure of the Catania airport, about 30 km SSE. Lava effused from the NNE end of the fissure, traveled about 180 m, and flowed into NEC. Activity at the fissure began to decrease during the afternoon of 6 July and ceased during the early afternoon of 7 July. The Alert Level remained at Yellow (the second lowest level on a four-level scale) according to the Dipartimento della Protezione Civile.

Sources: Dipartimento della Protezione Civile,Sezione di Catania - Osservatorio Etneo (INGV)

The Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) reported that an eruption at Krakatau continued during 2-8 July. At 1405 on 2 July an eruption generated a gray-to-black ash plume that rose 200 m and drifted NW. The Aviation Color Code was raised to Orange (the second highest color on a four-color scale). At 1630 the Alert Level was raised to 3 (on a scale of 1-4), and the public was warned to stay 3 km away from the active crater. White-to-gray or white-to-brown ash plumes rose as high as 200 m during 3-4 July. Only white plumes were visible during 5-6 July, rising as high as 150 m. At 0821 on 7 July a dense gray plume rose 200 m and drifted NW; later that day plumes of various color combinations also rose as high as 200 m.

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

The Kamchatkan Volcanic Eruption Response Team (KVERT) reported that an explosion at Mutnovsky occurred at 0819 on 1 July, lasted around three minutes, and generated an ash plume that rose 3.5 km above the summit and drifted several kilometers W. The Aviation Color Code (ACC) was raised to Orange (the second highest level on a four-color scale) at 2146. No additional explosions were detected; at 0420 on 2 July the ACC was lowered to Yellow. Weather clouds obscured satellite views during 2-5 July. A thermal anomaly was identified in satellite images during 6-7 July, but with decreasing temperatures. At 0316 on 9 July the ACC was lowered to Green. Dates are based on UTC; specific events are in local time where noted.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

The Japan Meteorological Agency (JMA) reported ongoing eruptive activity at Minamidake Crater (Aira Caldera?s Sakurajima volcano) during 29 June-6 July. A very small eruptive event was detected on 29 June, and crater incandescence was visible in nighttime webcam images during 29 June-3 July. The Alert Level remained at 3 (on a 5-level scale), and the public was warned to be cautious within 2 km of both the Minimadake and Showa craters.

Source: Japan Meteorological Agency (JMA)

The Wellington Volcanic Ash Advisory Center (VAAC) reported that satellite and webcam views of Ambae showed continuous plumes of steam and sulfur dioxide, with intermittent ash signals, on 4 July. The plumes rose 2.1-2.3 km (7,000-8,000 ft) a.s.l. and drifted NW. During 5-6 July ash plumes that were sometimes continuous rose 3-4.6 km (7,000-15,000 ft) a.s.l, or as high as 3 km above the summit, and drifted NW. Hotspots were also identified in satellite images. Weather clouds obscured views on 7 July. Ash plumes rose to 3.7 km (12,000 ft) a.s.l. and drifted E on 8 July. The Alert Level remained at 3 (on a scale of 0-5), and the public was warned to stay outside of Danger Zone B, defined as a 3-km radius around the active vents in Lake Voui, and to stay away from drainages during heavy rains.

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

The Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) reported that unrest at Awu decreased in July, after an increase in seismicity was recorded in May. During 1-7 July the seismic network recorded 116 shallow volcanic earthquakes (an average of 16 events per day), and 17 deep volcanic earthquakes. These counts were significantly lower than the elevated activity on 19 May when 104 shallow volcanic earthquakes were recorded. At 1300 on 8 July the Alert Level was lowered to 2 (on a scale of 1-4) and the public was warned to stay 3 km away from the crater?s center.

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

The Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) reported that eruptive activity at Dukono continued during 2-8 July. Plumes were not visible on 2 July. White-to-gray ash plumes rose 300-1,500 m above the summit during 3-5 July. White plumes rose 400-500 m above the summit during 6-7 July. The Alert Level remained at Level 2 (on a scale of 1-4) and the public was warned to stay 4 km away from the Malupang Warirang Crater.

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

The Instituto Nacional de Sismología, Vulcanologia, Meteorologia e Hidrología (INSIVUMEH) reported that eruptive activity at Fuego continued during 1-8 July. Daily Strombolian explosions recorded by the seismic network, at rates of 5-12 per hour when reported, generated gas-and-ash plumes that rose as high as 1.1 km above the summit and drifted as far as 40 km SW, W, NW, and N. Rumbling sounds, shock waves, and/or sounds associated with explosions were reported daily. Explosions ejected incandescent material as high as 300 m above the summit and onto the flanks, causing incandescent block avalanches to descend the flanks; notably avalanches descended the Seca (W), Taniluyá (SSW), Ceniza (SSW), Trinidad (SSW), Las Lajas (SE), and Honda drainages, sometimes reaching vegetated areas. Minor ashfall was reported in Yepocapa (8 km NW) during 2-3 July and in Panimaché (8 km SW), Morelia (10 km SW), Santa Sofia (12 km SW), and surrounding areas during 3-4 July.

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

The Alaska Volcano Observatory (AVO) reported that slow lava effusion continued to feed a thick flow in Great Sitkin?s summit crater during 1-8 July. Seismicity was low. Webcam and satellite images were often obscured by weather clouds. The Volcano Alert Level remained at Watch (the third level on a four-level scale) and the Aviation Color Code remained at Orange (the third color on a four-color scale).

Source: US Geological Survey Alaska Volcano Observatory (AVO)

The Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) reported that activity at Ibu continued during 2-8 July, with daily eruptive events recorded by the seismic network. Gray or white-to-gray ash plumes rose 200-600 m above the summit and drifted E, NE, and NW almost daily; weather conditions obscured views on 3 July. Incandescence at the summit was visible in some nighttime webcam images. The Alert Level remained at 2 (the second lowest level on a four-level scale) and the public was advised to stay 2 km away from the active crater and 3.5 km away from the N crater wall opening.

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

The Philippine Institute of Volcanology and Seismology (PHIVOLCS) reported continuing eruptive activity at Kanlaon during 2-7 July. The seismic network recorded 3-10 daily volcanic earthquakes. Sulfur dioxide emissions ranged from 1,234 to 2,531 tonnes per day. Volcanic emissions generally rose as high as 1.3 km above the summit and drifted NW, W, and SW. There were 2-3 periods of ash emissions on 2, 4, and 6 July, each lasting five minutes to nearly three hours. Two of the events on 4 July were recorded by webcams; at 0502 a grayish ash plume rose 300 m above the crater rim and drifted SW and during 1339-1404 grayish ash plumes rose as high as 200 m above the crater rim and drifted SW. At 1343 on 6 July a grayish ash plume rose 900 m above the crater rim and drifted SW. The Alert Level remained at 2 (on a scale of 0-5); the public was warned to stay out of the 4-km-radius Permanent Danger Zone (PDZ) and pilots were advised to avoid flying close to the summit.

Source: Philippine Institute of Volcanology and Seismology (PHIVOLCS)

The Hawaiian Volcano Observatory (HVO) reported that the eruption within Kilauea?s Kaluapele summit caldera, characterized by episodic fountaining, incandescence, and intermittent spatter from craters along the SW margin of Halema?uma?u Crater, continued at variable levels during 1-7 July. Moderate-to-strong incandescence persisted at the S vent. Flaming at the N vent was visible during 1-2 July. Incandescence at the N vent was variable in intensity and intermittent at other times of the week. During a helicopter overflight on 7 July HVO geologists observed an incandescent lava surface deep within the S vent; no lava was visible in the N vent. The Volcano Alert Level remained at Advisory (the second lowest level on a four-level scale) and the Aviation Color Code remained at Yellow (the second lowest color on a four-color scale).

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)