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 Wellington Volcanic Ash Advisory Center (VAAC) reported that emissions of ash-and-gas plumes from Ambae were identified during 4-5 June using satellite and webcam images. The plumes rose 3 km (10,000 ft) a.s.l. and drifted S. 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 Servicio Nacional de Geología y Minería (SERNAGEOMIN), Servicio Nacional de Prevención y Respuesta ante Desastres (SENAPRED), and the Servicio Geológico Minero Argentino (SEGEMAR) stated that seismicity at Nevado de Longaví gradually declined after a seismic swarm on 20 May. A few isolated seismic events were recorded during 21-31 May, with activity close to baseline levels. The Alert Level remained at Yellow (the second lowest level on a four-color scale) and SENAPRED maintained a ?Preventative Early Warning? for the communities of Longaví (53 km WNW), Linares (55 km NW), and Colbún (60 km NNW).

Sources: Servicio Geológico Minero Argentino (SEGEMAR),Servicio Nacional de Geología y Minería (SERNAGEOMIN),Sistema y Servicio Nacional de Prevención y Repuesta Ante Desastres (SENAPRED)

The Rabaul Volcano Observatory (RVO) reported that the eruption at Titan Ridge continued during 4-9 June. The number of hydroacoustic signals per day decreased during 4-8 June, followed by a minor increase on 9 June. A narrow but dense steam plume drifted about 50 km NW at low altitudes due to strong winds. A possible small intermittent plume may have risen from an area just to the SW of the main plume. Despite a reduction in the number of daily acoustic events, thermal anomalies around the plume area had intensified. Significant amounts of floating pumice, forming thick and extensive rafts, continued to wash up on the shores of the Admiralty Islands. According to a news article pumice rafts impacted the S coastline of Manus Island and made boat access difficult or impossible. An observer reported that one of the pumice rafts was about 3 km wide, 5 km long, and around 5 m deep. The rafts covered reefs and grasses, and caused the deaths of fish.

Sources: Rabaul Volcano Observatory (RVO),Radio New Zealand

The Japan Meteorological Agency (JMA) reported ongoing eruptive activity at Minamidake Crater (Aira Caldera?s Sakurajima volcano) during 1-8 June. Sulfur dioxide emissions were high, averaging 2,900 tons per day on 3 June. Very small eruptive events were detected during 1-5 June. Continuous ash emissions during 0652-0755 on 7 June rose as high as 1.3 km above the crater rim and drifted SE and W. A news article stated that ash fell across Kagoshima City, though this was unconfirmed by JMA. An explosion later that day, at 1907, was recorded by the seismic network but not visually observed. An explosion at 2141 on 8 June generated an ash plume that rose 700 m above the crater rim and drifted SE and ejected large blocks 500-700 m from the crater. 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 Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) reported that eruptive activity at Dukono continued during 4-10 June. Daily white-to-gray or gray-to-black plumes rose 300-2,000 m above the summit and drifted N, NE, E, and NW. Faint rumbling was heard at the Dukono observation post (11 km N) on 6 June. 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 3-10 June. Daily Strombolian explosions recorded by the seismic network, at rates of 4-12 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 NW, W, and SW. Rumbling sounds, shock waves, and/or sounds associated with gas emissions were reported almost every day. Explosions ejected incandescent material as high as 300 m above the summit and onto the flanks, causing incandescent block avalanches to descend the W, SW, and S flanks; notably the avalanches descended the Seca (W), Taniluyá (SSW), Ceniza (SSW), Las Lajas (SE), and Honda drainages, sometimes reaching vegetated areas. Ashfall was reported in communities on the W flanks or around the crater area on a few of the days. Rainfall during the evenings of 4 to 5 June triggered lahars on both days that descended the Ceniza drainage and were composed of a mixture of water, fine volcanic material, tree branches and trunks, and blocks measuring from 30 cm to 3 m in diameter. During the evening of 6 June lahars of similar composition descended the El Jute and Las Lajas drainages.

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 3-10 June. A satellite image acquired on 6 June confirmed that slow growth was concentrated along the E margin. Daily minor seismicity was detected by the seismic network. Weather clouds sometimes prevented webcam and satellite observations, though slightly elevated surface temperatures were visible in satellite images during 5-10 June. 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 4-10 June, with daily eruptive events recorded by the seismic network. Daily gray or white-to-gray ash plumes rose 300-800 m above the summit and drifted in multiple directions. 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 4-10 June. The seismic network recorded 5-15 daily volcanic earthquakes; during 4-8 June the seismic counts included 1-4 daily periods of volcanic tremor lasting 3 minutes to two hours and 39 minutes each. Sulfur dioxide emissions ranged from 990 to 2,682 tonnes per day. Daily volcanic emissions rose as high as 1.5 km above the summit and drifted SE, S, and W. There were 1-4 daily periods of ash emissions during 4-8 June lasting as short as five minutes to as long as two hours and 39 minutes. Specifically, the webcam recorded grayish ash emissions at 0553 on 6 June rising 800 m above the crater rim and drifting 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 3-10 June. Robust gas plumes rose from both the N and S vents though the week. Bright and continuous incandescence persisted at the S vent and flames likely caused by the ignition of volcanic gases escaping the vent were periodically observed. Incandescence at the N vent was intermittent. A small lava flow oozed out of the main cooling flow overnight during 3-4 June. The Volcano Alert Level remained at Advisory and the Aviation Color Code remained at Yellow.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

The Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) reported that activity continued at Lewotobi Laki-Laki during 2-10 June. Two dense gray ash plumes rose 600 m and 1,000 m above the summit and drifted in multiple directions on 2 June. A few dense gray ash plumes were visible on 4 June rising 800-1,200 m above the summit and drifted SW, W, and NW. Multiple daily dense gray ash plumes rose as high as 2.5 km above the summit and drifted SW, W, and NW during 5-10 June. Incandescence at the summit and incandescent material being ejected above the summit and onto the flanks were visible in webcam images at 1828 and 2250 on 5 June. Summit incandescence was visible in webcam images on 6 June (at 0049, 0117, and 0213), and 10 June (at 2230 and 2355). The Alert Level remained at 3 (on a scale of 1-4), and the public was warned to stay 5 km away from the center of Laki-Laki.

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

The Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) reported ongoing eruptive activity at Lewotolok during 4-10 June. Daily white plumes rose as high as 500 m above the summit and drifted in multiple directions. Incandescent material was ejected above the summit on 6 June, and summit incandescence was visible in a webcam image at 2150 on 8 June and at 2343 on 10 June. Rumbling was heard at the observation post (6 km SW) on 10 June. The Alert Level remained at 2 (on a scale of 1-4) and the public was warned to stay 2 km away from the summit.

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