Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week of 11 April - 17 April 2018

Agung | Bali (Indonesia) : Based on webcam views, satellite data, and ground-based observations, the Darwin VAAC reported that on 11 April an event at Agung generated an ash plume that rose to an altitude of 3.7 km (12,000 ft) a.s.l. and drifted SW.

Aira | Kyushu (Japan) : JMA reported that there were four events and nine explosions at Minamidake crater (at Aira Caldera’s Sakurajima volcano) during 9-16 April. Tephra was ejected as far as 1.3 km from the crater, and plumes rose as high as 2.5 km above the crater rim. Crater incandescence was visible on most nights. The Alert Level remained at 3 (on a 5-level scale).

Bagana | Bougainville (Papua New Guinea) : Based on analyses of satellite imagery and model data, the Darwin VAAC reported that during 14-15 April ash plumes from Bagana rose to altitudes of 2.1-2.4 km (7,000-8,000 ft) a.s.l. and drifted about 110 km SW.

Cleveland | Chuginadak Island (USA) : AVO reported that a small explosion at Cleveland was detected in seismic and infrasound data at 0759 on 13 April; no eruption plume was visible in satellite images. The Aviation colour Code remained at Orange and the Volcano Alert Level remained at Watch.

Dukono | Halmahera (Indonesia) : Based on analyses of satellite imagery, wind model data, and notices from PVMBG, the Darwin VAAC reported that during 11-16 April ash plumes from Dukono rose to an altitude of 2.1 km (7,000 ft) a.s.l. and drifted mainly NW, W, SW, and NNE.

Ebeko | Paramushir Island (Russia) : Volcanologists in Severo-Kurilsk (Paramushir Island), about 7 km E of Ebeko, observed explosions during 7 and 11-12 April that sent ash plumes as high as 1.8 km (5,900 ft) a.s.l. Ashfall was reported in Severo-Kurilsk on 6 April. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Fuego | Guatemala : INSIVUMEH reported that on 9 April a lahar descended the Seca (Santa Teresa) drainage on Fuego’s W flank. The lahar was 10 m wide, 1.5 m deep, and had a consistency similar to cement mix. During 12-13 April explosions generated ash plumes that rose as high as 1 km and drifted 15 km SW and W. Incandescent material was ejected as high as 300 m above the crater rim, and generated avalanches of material in the Seca, Cenizas (SSW), Las Lajas (SE), and Honda (E) ravines. Ash fell in areas downwind including in Santa Sofía (12 km SW), Morelia (9 km SW), Panimaché (8 km SW), (SSW), Las Lajas (SE), and Honda (E) ravines. Ash fell in areas downwind including in Santa Sofía (12 km SW), Morelia (9 km SW), Panimaché (8 km SW), El Porvenir (8 km ENE), and Finca Palo Verde.

Activity increased on 14 April and remained elevated through 17 April. Moderate-to-strong explosions were detected at a rate of 6-9 per hour, and sometimes produced shock waves that vibrated houses in Morelia and Panimaché. Dense ash plumes rose as high as 1.1 km and drifted 20 km W and S, though winds also carried the ash to higher altitudes to the SE. Incandescent material was ejected as high as 300 m above the crater rim, and generated avalanches of material in the crater area. Ashfall was reported in areas downwind including in Santa Sofía, Morelia, Panimaché I and II, El Porvenir, and Finca Palo Verde. The rate of explosions increased to 7-10 per hour on 16 April; explosions sometimes caused structures in Panimache, Morelia, La Reina, and Alotenango (8 km ENE) to vibrate. A lava flow traveled 1.3 km down the Seca drainage.

Karymsky | Eastern Kamchatka (Russia) : KVERT reported that a weak thermal anomaly over Karymsky was identified in satellite data on 11 April. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Kilauea | Hawaiian Islands (USA) : During 11-17 April HVO reported that the lava lake continued to rise, fall, and spatter in Kilauea’s Overlook crater. The lake level was high, with spattering visible from HVO and Jaggar Museum; by 16 April the lake level was 10 m below the rim of the Overlook crater. Surface lava flows were active above Pulama pali. On 11 April a moderate swarm of over 200 earthquakes occurred at depths of 7-9 km below the summit. The largest event was a M 2.4. Seismicity returned to background levels at 0230. Three minor ledge collapses were detected on 12 April, one at 1157 and two just after 1830. Surface lava flows were active above Pulama pali; on 13 April most scattered breakouts were within 2.2 km from Pu'u 'O'o Crater, and one was about 5 km away.

Mayon | Luzon (Philippines) : PHIVOLCS reported that during 11-17 April white steam plumes from Mayon drifted NW, WNW, WSW, and SW. Crater incandescence was visible at night. The sulfur dioxide flux was 2,800, 1,918, 1,621, and 1,617 tonnes/day on 11, 12, 13, and 16 April, respectively. The Alert Level remained at 2 (on a 0-5 scale) and PHIVOLCS reminded residents to stay away from the 6-km-radius Permanent Danger Zone and the 7-km Extended Danger Zone on the SSW and ENE flanks.

Sabancaya | Peru : Observatorio Vulcanológico del Sur del IGP (OVS-IGP) and Observatorio Vulcanológico del INGEMMET (OVI) reported that explosive activity at Sabancaya was similar to the previous week; explosions averaged 15 per day during 9-15 April. Seismicity was dominated by long-period events, with signals indicating emissions. Gas-and-ash plumes rose as high as 2.2 km above the crater rim and drifted 30 km NW and SW. Minor ashfall was reported in Huambo and Cabanaconde. The MIROVA system detected three thermal anomalies. The report noted that the public should not to approach the crater within a 12-km radius.

Sheveluch | Central Kamchatka (Russia) : KVERT reported that a weak thermal anomaly over Sheveluch was identified in satellite images during 6 and 10-12 April. The Aviation colour Code remained at Orange.

Turrialba | Costa Rica : The Washington VAAC reported that on 11 April an ash emission from Turrialba were seen through an OVSICORI-UNA web camera.