According to news articles and the Vanuatu Red Cross, residents of Ambae began to evacuate the island during 1-8 August under the governments orders due to the effects of significant ashfall from the ongoing eruption at Lake Voui. The Red Cross noted that by 8 August over 3,000 people had been moved to Espiritu Santo (W) and Maewo (NE) islands. Video from 3 August showed lahars blocking roads in S Ambae.

Sources: Radio New Zealand, Vanuatu Red Cross

Based on two field inspections and webcam data, INGV reported that during 30 July-5 August activity at Etna was characterized by gas emissions at the summit craters and Strombolian activity. Three vents at the bottom of the Bocca Nuova crater were active, with gas emissions rising from two vents and sporadic Strombolian activity occurring at a third. Three vents were also active at the bottom of Northeast Crater (NEC); one produced ash emissions, one steam emissions, and Strombolian explosions at the third ejected incandescent material as high as the crater rim. After several months of quiet conditions, explosive activity resumed at the E crater on the E flank of the New Southeast Crater (NSEC). The activity began at 0608 on 1 August with a brownish-gray ash emission that rose several hundred meters above the summit. The event was followed by more ash emissions and then Strombolian activity in the evening.

Source: Sezione di Catania - Osservatorio Etneo (INGV)

PVMBG reported that on 2 August multiple events at Anak Krakatau generated ash plumes that rose as high as 300 m above the summit and drifted N. A dense, black ash plume from an event at 1757 rose 200 m and drifted N. During 5-7 August dense gray ash plumes rose 200-600 m above the summit, and summit incandescence was visible at night. 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.

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

Servicio Nacional de Geología and Minería (SERNAGEOMIN) Observatorio Volcanológico de Los Andes del Sur (OVDAS) and ONEMI reported continuing activity through 6 August associated with growth of the Gil-Cruz lava dome in Nevados de Chillán’s Nicanor Crater. Seismicity was at moderate-to-high levels, and consisted of long-period events and tremor. 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)

IG reported that the eruption at Sierra Negra continued during 1-7 August. Incandescence from active lava flows was visible daily. An increase of tremor began at 2220 on 3 August and lasted two hours, signifying a new pulse of activity on the N flank. Small gas emissions were visible on 4 August, and steam-and-gas emissions were noted on 6 August.

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

PVMBG reported that white plumes rose 100-300 m above Agung’s crater rim during 1 and 2-7 August. The Alert Level remained at 3 (on a scale of 1-4) with the exclusion zone set at a 4-km radius.

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

JMA reported that there were eight events and seven explosions at Minamidake crater (at Aira Caldera’s Sakurajima volcano) during 30 July-6 August, with ash plumes rising as high as 2.5 km above the crater rim and material ejected as far as 700 m. Crater incandescence was seldom visible at night. Sulfur dioxide emissions were very high at 3,200 tons per day on 2 August. The Alert Level remained at 3 (on a 5-level scale).

Source: Japan Meteorological Agency (JMA)

According to ONEMI, OVDAS-SERNAGEOMIN reported that during 16-31 July there were 107 volcano-tectonic events recorded at Copahue, and 266 earthquakes indicating fluid movement. Webcams recorded gas-and-ash plumes rising from El Agrio crater as high as 1.5 km and nighttime incandescence. The Alert Level remained at Yellow (second highest level on a four-color scale); SERNAGEOMIN recommended no entry into a restricted area within 1 km of the crater. ONEMI maintained an Alert Level Yellow (the middle level on a three-color scale) for the municipality of Alto Biobío.

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

Based on satellite data, wind model data, and notices from PVMBG, the Darwin VAAC reported that during 1 and 3-7 August ash plumes from Dukono rose to altitudes of 1.8-2.1 km (6,000-7,000 ft) a.s.l. and drifted N and NE.

Source: Darwin Volcanic Ash Advisory Centre (VAAC)

Volcanologists in Severo-Kurilsk (Paramushir Island), about 7 km E of Ebeko, observed explosions during 29-31 July and on 1 August that sent ash plumes as high as 6 km (19,700 ft) a.s.l. The Aviation Color Code remained at Orange (the second highest level on a four-color scale).

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

KVERT reported that a thermal anomaly over Karymsky was identified in satellite images during 27-29 and 31 July, as well as ash plumes drifting 200 km SE, E, and NE during 28-31 July. The Aviation Color Code remained at Orange (the second highest level on a four-color scale).

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

HVO reported that the eruption at Kīlauea's Lower East Rift Zone (LERZ) and within Halemaʻumaʻu Crater continued during 1-2 August, with lava flowing through the channel and into the ocean producing laze at several points along a broad 2-km-wide flow front at Ahalanui. A few spillovers from the channel set vegetation on fire. By 3 August the lava-flow velocity in the channel was low and on 4 August the output at Fissure 8 had waned. Part of the flow field shifted W about 250 m; the westernmost edge was about 70 m NE of the boat ramp in Isaac Hale Park by 5 August. The lava channel was completely crusted over by 6 August, and a lava lake bubbled in the Fissure 8 cone. The laze plumes at the ocean entry were greatly diminished. During 7-8 August the lava lake in Fissure 8 was 5-10 m below the spillway into the channel. A decreasing number of small active ooze outs near the coast were visible.

A collapse event at the summit was recorded at 1155 on 2 August. Seismicity increased afterwards as has been typical since early on in the LERZ eruption, but then decreased along with the rate of deformation. By 7 August deformation had almost stopped. The quiet conditions at the summit represented a significant change from the pattern of seismicity and deformation detected over the past several months.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

Observatorio Vulcanológico del Sur del IGP (OVS-IGP) and Observatorio Vulcanológico del INGEMMET (OVI) reported that explosions at Sabancaya averaged 19 per day during 30 July-5 August. Hybrid earthquakes were infrequent and low magnitude. Gas-and-ash plumes rose as high as 2.6 km above the crater rim and drifted 30 km SE, E, and NE. On 2 August the sulfur dioxide gas flux was high at 5,000 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)

KVERT reported that satellite images showed a thermal anomaly over Sheveluch during 27-29 July and 1-2 August. The Aviation Color Code remained at Orange (the second highest level on a four-color scale).

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

OVSICORI-UNA reported that during 2-4 August activity at Turrialba was characterized by sporadic, passive gas-and-ash emissions. Events at 0023 and 0700 on 2 August generated diffuse ash plumes that rose 1 km and 300 m, respectively, and drifted W. An event at 1600 on 4 August produced a diffuse ash plume that rose 300 m.

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