Volcano World

JMA reported that nighttime incandescence at Minamidake Crater (at Aira Caldera?s Sakurajima volcano) was visible during 1-8 August. The seismic network recorded 25 eruptive events and seven explosions. Volcanic plumes rose as high as 2.8 km above the crater rim and material was ejected material as high as 1.3 km above the summit. The Alert Level remained at 3 (on a 5-level scale), and residents were warned to stay 2 km away from the crater.

Source: Japan Meteorological Agency (JMA)

The Icelandic Meteorological Office (IMO) reported that seismicity at Grmsvtn had declined to normal levels during the past few days, and no significant variations from background levels were observed in geochemical or deformation data. On 9 August the Aviation Color Code was lowered to Green.

Source: Icelandic Meteorological Office (IMO)

JMA reported that minor eruptive activity off the coast at Ioto (Iwo-jima) had been visible daily during 11-31 July. On 14 July pumice pieces from the eruption washed up onto the shore at Onohama and were photographed during a field survey conducted by the National Research Institute for Earth Science and Disaster Prevention. JMA scientist visited the site on 31 July and confirmed the pumice deposits on the beach. They saw eruptive activity every few minutes, and gray, tephra-laden columns of water being ejected 20-30 m above the ocean?s surface. A satellite image on 4 August showed a small rounded gray zone at the water surface and a plume of discolored water drifting NE.

Sources: Japan Meteorological Agency (JMA) ,Sentinel Hub

The fissure eruption of the Krsuvk-Trlladyngja volcanic system that began at around 1318 on 3 August continued at least through 9 August. Numerous small lava fountains rose along the fissure, located near the border of the previous flow field N of Fagradalsfjall, and lava flows traveled downslope to the NW. Scientists from the Institute of Earth Sciences stated that the initial flow rate was 5-10 times greater than the flow rate at the start of the 2021 eruption, based on model estimates, field data, and satellite measurements. The flow rate was about 32 cubic meters per second during the initial hours of the eruption, then decreased to an average of 18 cubic meters per second from 1700 on 3 August until 1100 on 4 August, by which time about 1.6 million cubic meters of lava had covered an area of 0.14 square kilometers. The average flow thickness was around 11 m. According to a news article the length of the active fissure had decreased and the middle part of the fissure was the most active. On 5 August Icelandic Meteorological Office (IMO) reported that the number of daily earthquakes declined after the eruption began and deformation stabilized. Thousands of people were walking on the trails to view the eruption; authorities warned the public to heed inclement weather warnings, and closed access to the site during 7-9 August due to weather conditions and trail maintenance.

Sources: Icelandic Meteorological Office (IMO),Icelandic National Broadcasting Service (RUV),Icelandic National Broadcasting Service (RUV),Icelandic National Broadcasting Service (RUV),Institute of Earth Sciences

KVERT reported that moderate activity at Ebeko was ongoing during 28 July-4 August. According to volcanologists in Severo-Kurilsk (Paramushir Island, about 7 km E) explosions generated ash plumes that rose up to 4.5 km (14,800 ft) a.s.l. and drifted in multiple directions. A thermal anomaly over the volcano was identified in satellite images during 1 and 3-4 August. The Aviation Color Code remained at Orange (the second highest level on a four-color scale). Dates are based on UTC times; specific events are in local time where noted.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

INSIVUMEH reported that 3-10 explosions per hour were recorded at Fuego during 2-9 August, generating ash plumes that rose as high as 1.1 km above the crater rim. The ash plumes drifted as far as 30 km W and SW, causing daily ashfall in areas downwind including Morelia (9 km SW), Panimach I and II (8 km SW), Santa Sofa (12 km SW), El Porvenir (8 km ENE), Los Yucales (12 km SW), Sangre de Cristo (8 km WSW), El Porvenir (8 km ENE), San Pedro Yepocapa (8 km NW), Ojo de Agua, and Finca Palo Verde. Daily shock waves rattled structures in communities around the volcano and rumbling was occasionally heard. Daily block avalanches descended the Ceniza (SSW), Seca (W), Trinidad (S), Taniluy (SW), Honda, and Las Lajas (SE) drainages. Explosions ejected incandescent material 100-300 m above the summit each day.

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

AVO reported that slow lava effusion at Great Sitkin likely continued during 2-9 August; no changes to the flow lengths were visible but the lava had deepened around the vent. Weather clouds often obscured satellite and webcam views during most of the week, though no activity was visible when views were clear. Seismicity was low and occasional local earthquakes were recorded. Elevated surface temperatures were identified in satellite images during 5-9 August. The Aviation Color Code and the Volcano Alert Level remained at Orange and Watch, respectively.

Source: US Geological Survey Alaska Volcano Observatory (AVO)

KVERT reported that the eruption at Karymsky continued during 29 July-4 August. Explosions during 29-31 July, 1-2 August, and 4 August produced ash plumes that rose 4-8 km (13,100-26,200 ft) a.s.l. and drifted 230 km S, SE, and E. A thermal anomaly over the volcano was identified in satellite images during 31 July-4 August. The Aviation Color Code remained at Orange (the second highest level on a four-color scale). Dates are based on UTC times; specific events are in local time where noted.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

HVO reported that lava continued to effuse from a vent in the lower W wall of Kilauea?s Halema`uma`u Crater during 2-9 August, entering the lava lake and flowing onto the crater floor. The lake level remained within the bounding levees. Daily minor ooze-outs were visible along the margins of the crater floor. Intense incandescence from the W vent was visible during 5-9 August. Aviation Color Code and the Volcano Alert Level remained at Orange and Watch, respectively.

Source: US Geological Survey Hawaiian Volcano Observatory (HVO)

PVMBG reported that the eruption at Anak Krakatau continued during 3-9 August. Several eruptive events occurred on 3 August (at 0034, 0115, and 1540), sometimes producing dense black ash plumes that rose as high as 1.5 km above the summit and drifted SW. At 0926 on 4 August a dense gray-to-black ash plume rose 1.5 km and drifted N. Incandescence at or near the vent was seen in nighttime photos on most days. Diffuse white plumes were visible rising from the volcano during 7-8 August. The Alert Level remained at 3 (on a scale of 1-4), and the public was warned to stay at least 5 km away from the crater.

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