Friday 22 June 2018

Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week of13 June – 19 June 2018

Agung | Bali (Indonesia) : PVMBG reported that at 1105 on 13 June an event at Agung produced a dense ash plume that rose around 2 km above the crater rim and drifted SW and W. Based on analysis of the seismic data, the event lasted two minutes and 12 seconds. Another event was detected at 2115 on 15 June, though foggy conditions prevented estimations of the ash plume height; ash fell in areas W, including in Puregai (7 km W). The Alert Level remained at 3 (on a scale of 1-4) and the 4-km-radius exclusion zone was unchanged.

Aira | Kyushu (Japan) : JMA reported that there were eight events at Minamidake crater (at Aira Caldera’s Sakurajima volcano) during 11-15 June, with ash plumes rising as high as 1.6 km above the crater rim. An explosive event at 0719 on 16 June 2018 generated an ash plume that rose 4.7 km (the first time that a plume rose over 4 km since 2 May 2017) and ejecting tephra as far as 1.1 km. A pyroclastic flow traveled down the SW flank. The last pyroclastic flow originated at the Showa Crater on 1 April 2018. The Alert Level remained at 3 (on a 5-level scale).

Cleveland | Chuginadak Island (USA) : AVO reported that low-level unrest at Cleveland continued during 13-19 June. Elevated surface temperatures were evident in satellite data on days when the area was cloud-free. Nothing unusual was observed in seismic or pressure sensor data. The Aviation colour Code remained at Yellow and the Volcano Alert Level remained at Advisory.

Dukono | Halmahera (Indonesia) : Based on PVMBG observations and satellite data, the Darwin VAAC reported that during 13-17 June ash plumes from Dukono rose to altitudes of 1.8-2.1 km (6,000-7,000 ft) a.s.l. and drifted in multiple directions.

Karymsky | Eastern Kamchatka (Russia) : KVERT reported that a thermal anomaly over Karymsky was last identified in satellite images on 20 May. The Aviation colour Code was lowered to Yellow (the second lowest level on a four-colour scale) on 15 June.

Kilauea | Hawaiian Islands (USA) : HVO reported that the eruption at Kilauea’s Lower East Rift Zone (LERZ) and at Overlook Crater within Halema`uma`u Crater continued during 13-19 June. Lava fountaining and spatter was concentrated at Fissure 8, feeding lava flows that spread through Leilani Estates and Lanipuna Gardens subdivisions, and built out the coastline where the fast-moving flow entered the ocean in the area of the former Kapoho Bay. Minor lava activity at Fissures 16/18 was occasionally noted, and spattering was visible at Fissure 6 on 16 June. Hawai‘i County Civil Defense reported that by 17 June a total of 533 homes had been destroyed due to lava flows.

Inward slumping of the crater rim and walls of Halema`uma`u continued, adjusting from the withdrawal of magma and subsidence of the summit area. Steam plumes rose from areas in the crater as well as from circumferential cracks adjacent to the crater. Summit explosions occurred daily, producing ash plumes that rose as high as 3 km (10,000 ft) a.s.l. On 18 June residents reported feeling a large earthquake at 0613 and hearing roaring. The event was followed by an ash plume rising to 1.5 km (5,000 ft) a.s.l.

Fountaining at Fissure 8 was stable; lava fountains rose as high 60 m from a 52-m-high spatter cone. Pele's hair and other volcanic glass from the fountaining fell within Leilani Estates. The fountains continued to feed the fast-moving lava flow that traveled NE, and then SE around Kapoho Crater, and into the ocean. Occasional overflows sent small flows down the sides of the channel. Lava entering the ocean built a lava delta that by 16 June was just over 130 hectares in area. A plume of laze rose from the entry points. An area of thermal upwelling in the ocean out from the visible lava-delta front was visible, suggesting lava flowing on the ocean floor.

Klyuchevskoy | Central Kamchatka (Russia) : KVERT reported that a weak thermal anomaly over Klyuchevskoy was identified in satellite images during 13-14 June. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Langila | New Britain (Papua New Guinea) : Based on analyses of satellite imagery and wind model data, the Darwin VAAC reported that on 17 June an ash plume from Langila rose to an altitude of 2.4 km (8,000 ft) a.s.l. and drifted W.

Pacaya | Guatemala : INSIVUMEH and CONRED reported that during 13 and 16-18 June Strombolian explosions at Pacaya’s Mackenney Crater ejected material as high as 50 m above the crater rim. An ash plume rose 3.5 km above the summit and drifted 10 km N and NE.

Sabancaya | Peru : Observatorio Vulcanológico del Sur del IGP (OVS-IGP) and Observatorio Vulcanológico del INGEMMET (OVI) reported that explosions at Sabancaya averaged 19 per day during 11-17 June. Hybrid earthquakes were infrequent and low magnitude. Gas-and-ash plumes rose as high as 1.4 km above the crater rim and drifted 30 km S and SE. The MIROVA system detected two thermal anomalies, and on 14 June the sulfur dioxide gas flux was high at 4,300 tons/day. The report noted that the public should not approach the crater within a 12-km radius.

Santa Maria | Guatemala : INSIVUMEH reported that on 13 June lahars descended Nimá I drainage on the S flank of Santa María's Santiaguito lava-dome complex. The lahars were 15-18 m wide and 1-2 m deep, and carried blocks 1.5 m in diameter and tree branches. CONRED noted that a Yellow Alert Level was declared for Quetzaltenango (18 km WNW) on 16 June due to continuing rains and an increased threat of lahars. Weak explosions during 16-18 June generated diffuse ash plumes that rose 700 m above the complex and drifted SW and W.

Sheveluch | Central Kamchatka (Russia) : KVERT reported that a weak thermal anomaly over Sheveluch was identified in satellite images during 13-14 June. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Sinabung | Indonesia : PVMBG reported that at 0700 on 15 June an event at Sinabung produced an ash plume that rose at least 500 m above the crater rim and drifted ESE. The Alert Level remained at 4 (on a scale of 1-4), with a general exclusion zone of 3 km and extensions of 7 km on the SSE sector, 6 km in the ESE sector, and 4 km in the NNE sector.

Yasur | Vanuatu : Based on webcam images, satellite data, and local visual observations the Wellington VAAC reported that during 14-15 and 17-18 June intermittent, low-level ash plumes from Yasur rose to altitudes of 0.9-1.2 km (3,000-4,000 ft) a.s.l. and drifted SW, W, and N.

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