Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week of 25 July – 31 July 2018

Agung | Bali (Indonesia) : According to PVMBG a ground-based observer reported that at 0041 on 25 July an event at Agung produced a dense ash-and-gas plume that rose 700 m and drifted E and SE. Seismic data recorded the event for two minutes and 15 seconds. At 1406 on 27 July an event lasting one minute and 32 seconds produced a dense ash-and-gas plume that rose 2 km and drifted W. The Alert Level remained at 3 (on a scale of 1-4) and the exclusion zone was stable at a 4-km radius.

Aira | Kyushu (Japan) : JMA reported that there were four events and 11 explosions at Minamidake crater (at Aira Caldera’s Sakurajima volcano) during 23-30 July, with ash plumes rising as high as 2.5 km above the crater rim and material ejected as far as 1.3 km. Crater incandescence was sometimes visible at night. Sulfur dioxide emissions were 2,100 tons per day on 26 July. 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 29-30 July ash plumes from Bagana rose to altitudes of 1.8-2.1 km (6,000-7,000 ft) a.s.l. and drifted SW. A thermal anomaly was visible on 29 July.

Cleveland | Chuginadak Island (USA) : AVO reported that unrest at Cleveland continued during 25-31 July, though nothing significant was detected in seismic or infrasound data. Meteorological cloud cover prevented views of the crater on most days, though steaming from the crater was visible in satellite and webcam views during 25-26 July. The Aviation colour Code remained at Orange and the Volcano Alert Level remained at Watch.

Dukono | Halmahera (Indonesia) : Based on PVMBG observations and satellite data, the Darwin VAAC reported that during 25-31 July ash plumes from Dukono rose to altitudes of 1.8-3.4 km (6,000-11,000 ft) a.s.l. and drifted N, NE, E, and S.

Ebeko | Paramushir Island (Russia) : Volcanologists in Severo-Kurilsk (Paramushir Island), about 7 km E of Ebeko, observed explosions during 20-21 and 25-26 July that sent ash plumes as high as 4 km (13,100 ft) a.s.l. An ash plume drifting about 15 km E was identified in satellite images on 20 July. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Fuego | Guatemala : INSIVUMEH reported that during 29-30 July avalanches of material descended the Cenizas drainage on Fuego’s SSW flank. Hot lahars generated by heavy rains on 30 July descended the Taniluyá (SW), Las Lajas (SE), El Jute (SE), and Cenizas drainages, carrying blocks 2-3 m in diameter and smelling of sulfur.

Karymsky | Eastern Kamchatka (Russia) : KVERT reported that an ash cloud from Karymsky was identified in satellite images drifting 100 km SE on 20 July, and thermal anomalies were visible on 25 and 27 July. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Kilauea | Hawaiian Islands (USA) : HVO reported that the eruption at Kilauea’s Lower East Rift Zone (LERZ) and within Halema`uma`u Crater continued during 18-24 July. Lava fountaining and spatter was concentrated at Fissure 8, feeding lava flows that continued to spread through Leilani Estates and Lanipuna Gardens subdivisions, and entered the ocean at Ahalanui.

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. Explosions from collapse events occurred about every other day (38.5 and 53.5 hours in between a few of the events). Sulfur dioxide emissions from the summit were very low.

Fountaining at Fissure 8 continued, producing Pele's hair and other volcanic glass that fell within Leilani Estates. The fountains continued to feed the lava flow that traveled NE, and then SSE, W of Kapoho Crater; lava occasionally overflowed the channel, and on 28 July ignited nearby vegetation. Small plumes of laze (a corrosive steam plume mixed with hydrochloric acid and fine volcanic glass particles) were generated at several points along a broad 2-km-wide flow front at Ahalanui. The westernmost edge was less than 175 m NE of the boat ramp in Isaac Hale Park (by 30 July).

Kirishimayama | Kyushu (Japan) : JMA reported that during 23-30 July white fumarolic plumes rose 300-500 m above a vent on the S side of Iwo-yama (also called Ioyama, NW flank of Karakuni-dake), a stratovolcano of the Kirishimayama volcano group. A hot pool of water was visible on the S side, and muddy water flowed down the W side. The Alert Level remained at 3 (on a scale of 1-5).

Piton de la Fournaise | Reunion Island (France) : OVPF reported that inflation at Piton de la Fournaise resumed after 13 July, the end of the last eruption. A period if increased seismicity was detected on 26 July, with 32 volcano-tectonic events less than 2 km deep being recorded during 0400-1600; 23 of those events were detected during 1200-1300.

Popocatepetl | Mexico : CENAPRED reported that each day during 25-31 July there were 24-42 steam-and-gas emissions from Popocatépetl, and nightly crater incandescence. Explosions were detected almost every day: five on 26 July; nine on 27 July; one on 28 July; three on 30 July. A series of gas-and-ash emissions began at 0307 on 31 July and lasted for 215 minutes. Ejected incandescent tephra landed on the flanks. The gas-and-ash plumes rose 2 km above the crater rim and drifted WSW, causing ashfall in Tetela del Volcán, Yecapixtla, Tlalnepantla, and Totolapan (Morelos state), and in Amecameca, Acuautla, Ecatzingo, Ozumba, and Tepetlixpa (Mexico state). The Alert Level remained at Yellow, Phase Two.

Rinjani | Lombok Island (Indonesia) : PVMBG and BNPB reported that a M 6.4 earthquake was recorded at 0547 on 29 July, shaking the islands of Lombok, Bali, and Sumbawa, and causing significant damage to buildings (including collapses) and roads, ground cracks, multiple injuries, and the death of 17 people in Lombok. The hypocenter was 24 km deep, and 47 km NE of Mataram City. Aftershocks were numerous and as large as M 5.7. The earthquakes caused remobilization of ash deposits on Rinjani as well as landslides. There were 1,226 visitors to the Mount Rinjani National Park Area at the time, and, according to news articles, about 690 climbers were on the volcano and had to be rescued. One person in the national park died from rockfalls. The Alert Level remained at 2 (on a scale of 1-4); the public was warned not to approach the crater within a 1.5-km radius.

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 23-29 July. Hybrid earthquakes were infrequent and low magnitude. Gas-and-ash plumes rose as high as 3 km above the crater rim and drifted 40 km SE and E. On 26 July the sulfur dioxide gas flux was high at 4,195 tons/day. The report noted that the public should not approach the crater within a 12-km radius.

Santa Maria | Guatemala : INSIVUMEH reported that during 28-30 July explosions at Santa María's Santiaguito lava-dome complex generated white plumes that rose 600-800 m and drifted SW. Avalanches of material descended the NW, E, and SE flanks of the lava dome.

Sheveluch | Central Kamchatka (Russia) : KVERT reported that satellite images showed a weak thermal anomaly over Sheveluch during 19 and 21-22 July. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Turrialba | Costa Rica : OVSICORI-UNA reported that during 23-31 July activity at Turrialba was characterized by sporadic, passive gas-and-ash emissions detected almost daily. The plumes rose no higher than 300 m above the vent rim, and drifted NW, W, and SW. Ashfall was reported in several neighborhoods in the Valle Central, including Coronado, Tibás (35 km WSW), Goicoechea (28 km WSW), and Moravia (31 km WSW) on 24 July, and in Tres Ríos (27 km SW) on 31 July. A sulfur odor was occasionally reported.