Report for Etna
INGV reported that during 6-12 August activity at Etna was similar to the previous week, characterized by gas emissions at the summit craters, Strombolian activity, and ash emissions. Strombolian explosions continued from vents in Bocca Nuova, and were particularly visible at night. Activity at Northeast Crater (NEC) consisted of frequent ash emissions and Strombolian explosions. Explosions at the E crater on the E flank of the New Southeast Crater (NSEC) generated gray-brown ash plumes that sometimes rose several hundred meters above Etna’s summit and quickly dissipated.
Report for Krakatau
PVMBG reported that during 8-13 August incandescence emanated from Anak Krakatau at night. According to the Darwin VAAC, satellite data showed an ash plume rising to an altitude of 1.2 km (4,000 ft) a.s.l. and drifting W on 11 August. 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.
Report for Agung
According to the Darwin VAAC, a webcam recorded an ash emission from Agung rising to an altitude of 4.3 km (14,000 ft) a.s.l. and drifting W. The Alert Level remained at 3 (on a scale of 1-4) with the exclusion zone set at a 4-km radius.
Report for Dukono
Based on satellite data, wind model data, and notices from PVMBG, the Darwin VAAC reported that during 8-14 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, NE, and E.
Report for Ibu
PVMBG reported that at 0259 on 13 August an event at Ibu generated an ash plume that rose 600 m above the crater rim. 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.
Report for Suwanosejima
JMA reported that during 3-10 August white plumes rose as high as 1 km above the rim of Suwanosejima’s Ontake Crater, and incandescence from the crater was visible at night. The Alert Level remained at 2 (on a 5-level scale).
Report for Aira
JMA reported that there were five events and three explosions at Minamidake crater (at Aira Caldera’s Sakurajima volcano) during 6-13 August, with ash plumes rising as high as 1.6 km above the crater rim and material ejected as far as 900 m. Crater incandescence was sometimes visible at night. The Alert Level remained at 3 (on a 5-level scale).
Report for Ebeko
Volcanologists in Severo-Kurilsk (Paramushir Island), about 7 km E of Ebeko, observed explosions during 3-10 August that sent ash plumes as high as 3.7 km (12,100 ft) a.s.l. An ash cloud identified in satellite data drifted about 65 km E during 7-8 August. The Aviation Color Code remained at Orange (the second highest level on a four-color scale).
Report for Karymsky
KVERT reported that a thermal anomaly over Karymsky was identified in satellite images on 4 August, and an ash cloud drifted 50 km SE on 7 August. The Aviation Color Code remained at Orange (the second highest level on a four-color scale).
Report for Sheveluch
KVERT reported that satellite images showed a thermal anomaly over Sheveluch during 6-7 August. The Aviation Color Code remained at Orange (the second highest level on a four-color scale).
Report for Great Sitkin
AVO reported that a small phreatic explosion at Great Sitkin was recorded by the seismic network at 1105 on 11 August. The event was preceded by small local earthquakes. Cloudy satellite images prevented views of the volcano during 12-14 August. The Aviation Color Code remained at Yellow and the Volcano Alert Level remained at Advisory.
Report for Kilauea
HVO reported that during 8-14 August activity at Kilauea was characterized by a slowly-circulating lava pond deep within the Fissure 8 vent (though the pond was crusted over by 14 August) and a billowing gas plume, and a few scattered ocean entries. The summit area was quiet except for occasional rockfalls into the crater. Fresh black sand from fragmented lava was transported SW by the ocean current, and accumulated in the Pohoiki harbor, creating a sandbar. The westernmost ocean entry was about 1 km NE of the harbor. Earthquake and deformation data indicated no magma movement or pressurization in the system.
Report for Fuego
INSIVUMEH reported that on 9 August heavy rain triggered lahars that traveled down the Seca drainage on Fuego’s W flank and the Mineral drainage, carrying tree trunks and blocks as large a 2 m in diameter. During 12-14 August weak-to-moderate explosions generated ash plumes that rose almost as high as 1 km above the summit and drifted W and SW. Incandescent material was ejected 150 m high, and avalanches of blocks descended the Cenizas (SSW), Las Lajas (SE), and Santa Teresa (W) drainages. Ashfall was reported in Santa Sofía (12 km SW), Morelia (9 km SW), Panimaché I (8 km SW), and finca Palo Verde.
Report for Pacaya
INSIVUMEH reported that during 12-14 August Strombolian explosions at Pacaya’s Mackenney Crater ejected material as high as 30 m above the crater rim. A 300-m-long lava flow originating from Mackenney Crater was visible on NW flank.
Report for Rincon de la Vieja
OVSICORI-UNA reported that a three-minute-long eruption at Rincón de la Vieja began at 1828 on 14 August. Foggy conditions prevented webcam views and an estimate of a plume height.
Report for Turrialba
OVSICORI-UNA reported that pulsating, passive ash emissions rising from Turrialba and drifting W were visible during periods of clear weather on 10 August. The next day a strong sulfur odor was reported in parts of Heredia (38 km W) and San José (36 km WSW).
Report for Sangay
In a special report IG stated that a new phase of activity at Sangay began on 8 August, with surficial activity characterized by low-energy ash emissions rising as high as 2.3 km above the crater rim and a possible new lava flow on the SE flank. The Washington VAAC reported that prior to 1500 on 8 August an ash emission rose to an altitude of 5.8 km (19,000 ft) a.s.l., or 500 m above the crater rim, and drifted SW. On 11 August a possible ash plume rose to 7.6 km (25,000 ft) a.s.l., or 2.3 km above the crater rim, and drifted WNW. Thermal anomalies were identified in satellite data on 14 August. That same day a webcam image showed incandescence on the upper part of the SE flank, suggesting a lava flow from the Ñuñurco dome. The report stated that no activity at Sangay had been observed since the last eruption ended in November 2017.
Report for Sierra Negra
IG reported that the eruption at Sierra Negra continued during 7-14 August. Incandescence from active NNW lava flows was visible almost nightly. A steam-and-gas plume rose 1.8 km a.s.l. and drifted W on 7 August.
Report for Sabancaya
Observatorio Vulcanológico del Sur del IGP (OVS-IGP) and Observatorio Vulcanológico del INGEMMET (OVI) reported that explosions at Sabancaya averaged 23 per day during 6-12 August. Hybrid earthquakes were infrequent and low magnitude. Gas-and-ash plumes rose as high as 2.9 km above the crater rim and drifted 40 km SE, E, and NE. The MIROVA system detected five thermal anomalies, and on 9 August the sulfur dioxide gas flux was high at 2,700 tons/day. The report noted that the public should not approach the crater within a 12-km radius.
Report for Nevados de Chillan
Servicio Nacional de Geología and Minería (SERNAGEOMIN) Observatorio Volcanológico de Los Andes del Sur (OVDAS) and ONEMI reported that at 1212 on 8 August an explosion-type earthquake was recorded by Nevados de Chillán’s seismic network. A grayish ash plume rose 1.5 km above Nicanor Crater and incandescent material was ejected around the vent. 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.
