Friday 30 March 2018

Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week of 21 March - 27 March 2018

Agung | Bali (Indonesia) : In a VONA, PVMBG reported that at 1009 on 26 March an event at Agung generated an ash plume that rose at least to an altitude of 3.6 km (11,650 ft) a.s.l. and drifted NW. The Alert Level remained at 3 (on a scale of 1-4) and the exclusion zone continued at a 4-km radius.

Aira | Kyushu (Japan) : JMA reported that there were 20 events at Minamidake crater (at Aira Caldera’s Sakurajima volcano) during 19-26 March, two of which were explosive. The first explosive event, at 0138 on 21 March, generated a plume that rose 1 km above the crater rim and into weather clouds. At 0228 on 26 March the second explosive event ejected tephra as far as 900 m from the crater and produced a plume that rose 2.8 km. The Alert Level remained at 3 (on a 5-level scale).

Dukono | Halmahera (Indonesia) : Based on analyses of satellite imagery, wind model data, and notices from PVMBG, the Darwin VAAC reported that during 21-25 March ash plumes from Dukono rose to an altitude of 1.8 km (6,000 ft) a.s.l. and drifted S, SE, and E.

Ebeko | Paramushir Island (Russia) : Based on observations by volcanologists in Severo-Kurilsk (Paramushir Island), about 7 km E of Ebeko, explosions during 18 and 21-22 March generated ash plumes that rose as high as 1.8 km (5,900 ft) a.s.l. Ashfall was reported in Severo-Kurilsk on 17 and 21 March. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Kilauea | Hawaiian Islands (USA) : During 21-27 March HVO reported that the lava lake continued to rise, fall, and spatter in Kilauea’s Overlook crater. Surface lava flows were active above and on Pulama pali. Webcams recorded incandescence from a small lava pond in a pit on the W side of Pu'u 'O'o Crater, and increased spattering which began on 22 March. Lava flowed out of a vent on the SE part of the crater onto the crater floor on 25 March, and expanded over the next few days.

Mayon | Luzon (Philippines) : PHIVOLCS reported that during 21-27 March activity at Mayon included periods of gravity-driven lava advancement, gas-and-steam emissions, rockfalls, and quiescence. Lava flows were about 3.3 km, 4.5 km, and 1.9 km long in the Mi-isi (S), Bonga (SE), and Basud (E) drainages, respectively. Steam-and-gas emissions drifted mainly SW. At 1039 and 2133 on 23 March pyroclastic flows traveled 4-5 km down the Mi-isi drainage, producing light brown ash clouds that drifted SW. The Alert Level remained at 3 (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.

Popocatepetl | Mexico : CENAPRED reported that during an overflight of Popocatépetl on 16 March scientists observed a small lava dome, number 78, at the bottom of the inner crater. The dome was 50 m in diameter and 30 m thick, and produced gas plumes visible above the main crater rim. The inner crater was 320 m in diameter and about 100 m deep; remnants of the previous dome had been deposited on the walls of the inner crater. Each day during 21-27 March there were 20-233 emissions, often containing slight amounts of ash. Incandescence from the crater was visible at night. Plumes of gas and water vapor drifted WSW, SSW, SSE, and SE. The Alert Level remained at Yellow, Phase Two.

Sabancaya | Peru : Observatorio Vulcanológico del Sur del IGP (OVS-IGP) and Observatorio Vulcanológico del INGEMMET (OVI) reported that explosive activity at Sabancaya was similar compared to the previous week; explosions averaged 17 per day during 19-25 March. Seismicity was dominated by long-period events, with signals indicating emissions. Gas-and-ash plumes rose 2.7 km above the crater rim and drifted 30 km SW. The sulfur dioxide flux was high, at 5,180 tons per day on 21 March. At 0853 on 7 March an ash plume rose 3.5 km and drifted more than 30 km NW. 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 thermal anomaly over Sheveluch was identified in satellite images during 18-19 and 21-22 March. The Aviation colour Code remained at Orange.

Suwanosejima | Ryukyu Islands (Japan) : Based on JMA notices and satellite data, the Tokyo VAAC reported that during 22-23 and 25-26 March events at Suwanosejima produced plumes that rose 1.2-2.4 km (4,000-8,000 ft) a.s.l. and drifted SE and NW.

Turrialba | Costa Rica : OVSICORI-UNA reported that an event at Turrialba at 0605 on 23 March generated a small ash plume that rose 100 m above the crater rim and drifted SW.

Villarrica | Chile : On 20 March POVI reported very weak and sporadic incandescence emanating from Villarrica’s crater, noting very low rates of activity since mid-December 2017.

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