Friday, 23 March 2018

Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week of 14 March - 20 March 2018

Aira | Kyushu (Japan) : JMA reported that during 12-19 March there were seven events and six explosions at Minamidake crater (at Aira Caldera’s Sakurajima volcano). Some of the explosions ejected tephra as far as 1.1 km and generated ash plumes that rose 1.7-2.3 km above the crater rim. The Alert Level remained at 3 (on a 5-level scale).

Ambrym | Vanuatu : On 19 March the Vanuatu Geohazards Observatory (VGO) reported that, based on photos taken during February-March, the lava lakes in Ambrym’s Benbow and Marum craters continued to be active and produced gas-and-steam emissions. Visitors occasionally reported smelling volcanic gases and hearing explosions. The Alert Level remained at 2 (on a scale of 0-5); the report reminded the public to stay outside of the Permanent Danger Zone defined as a 1-km radius from Benbow Crater and a 2.7-km radius from Marum Crater.

Cleveland | Chuginadak Island (USA) : AVO reported that seismic and infrasound sensors recorded a small explosion at Cleveland at 2219 on 14 March; ash plumes were not visible in subsequent cloudy satellite images. The Aviation colour Code remained at Yellow and the Volcano Alert Level remained at Advisory.

Dukono | Halmahera (Indonesia) : Based on analyses of satellite imagery, wind model data, and notices from PVMBG, the Darwin VAAC reported that during 14-20 March ash plumes from Dukono rose to altitudes of 1.8-2.7 km (6,000-9,000 ft) a.s.l. and drifted in multiple directions.

Ebeko | Paramushir Island (Russia) : Based on observations by volcanologists in Severo-Kurilsk (Paramushir Island), about 7 km E of Ebeko, explosions during 12-13 March generated ash plumes that rose as high as 2.7 km (8,900 ft) a.s.l. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Kadovar | Papua New Guinea : RVO reported that the lava dome at Kadovar’s SE Coastal Vent continued to grow, though slowly, with only a 1-m change detected during 10-20 March. Weak incandescence from the Main Crater was visible on 13 March. Bright incandescence from both the Main Crater and the SE Coastal vent was visible on 14 March, coincident with the start of dark gray ash emissions from both vents, lasting until 19 March.

Kilauea | Hawaiian Islands (USA) : During 14-20 March HVO reported that the lava lake continued to rise, fall, and spatter in Kilauea’s Overlook crater. Webcams recorded incandescence from a small lava pond in a pit on the W side of Pu'u 'O'o Crater. Surface lava flows were active above and on Pulama pali.

Kusatsu-Shiranesan | Honshu (Japan) : On 16 March JMA lowered the Alert Level for the Kusatsu-Shiranesan complex to 2 (on a 5-level scale) noting that the number of volcanic earthquakes had gradually declined since the 23 January eruption; seismicity remained elevated.

Mayon | Luzon (Philippines) : PHIVOLCS reported that during 13-20 March activity at Mayon was mostly characterized by periods of gravity-driven lava advancement, gas-and-steam emissions, rockfalls, and quiescence. Lava flows extended 3.3 km, 4.5 km, and 1.9 km long in the Mi-isi (S), Bonga (SE), and Basud (E) drainages, respectively. Sulfur dioxide emissions were between 969 and 2,077 tonnes/day. Steam-and-gas emissions drifted SW. An episode of lava fountaining was recorded during 0831-0832 on 14 March and produced a light-gray ash plume that rose 200 m above the crater and drifted SW. At 1347 on 16 March a pyroclastic flow traveled 4-5 km down the Mi-isi and Basud drainages. 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.

Sabancaya | Peru : Observatorio Vulcanológico del Sur del IGP (OVS-IGP) and Observatorio Vulcanológico del INGEMMET (OVI) reported that explosive activity at Sabancaya increased compared to the previous week; explosions averaged 17 per day during 12-18 March. Seismicity was dominated by long-period events, with signals indicating emissions. Gas-and-ash plumes rose 3 km above the crater rim and drifted 30 km NW, SW, and S. The sulfur dioxide flux was high, at 3,110 tons per day on 14 March. 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 11-14 March. The Aviation colour Code remained at Orange.

Suwanosejima | Ryukyu Islands (Japan) : Based on JMA notices and satellite data, the Tokyo VAAC reported that on 17 March an eruption at Suwanosejima produced a plume that rose 1.8 km (6,000 ft) a.s.l. and drifted W.

Yasur | Vanuatu : Based on visual observations and satellite data, the Vanuatu Geohazards Observatory reported on 19 March that explosions at Yasur remained strong. The Alert Level remained at 2 (on a scale of 0-4). VGO reminded residents and tourists that hazardous areas were near and around the volcanic crater, within a 395-m-radius permanent exclusion zone, and that volcanic ash and gas could reach areas impacted by trade winds.

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