Friday 31 March 2017

Volcanos

Roundup of Global Volcanic Activity - Ongoing Activity for the week of 22 March-28 March 2017

Bagana | Bougainville (Papua New Guinea) : Based on analyses of satellite imagery and model data, the Darwin VAAC reported that during 27-28 March a minor ash plume from Bagana rose to an altitude of 2.1 km (7,000 ft) a.s.l. and drifted 110 km SW and W.

Bogoslof | Fox Islands (USA) : AVO reported that no significant volcanic activity at Bogoslof was detected in seismic or infrasound data during 22-28 March, and satellite views were often obscured by clouds or showed nothing noteworthy. Weakly elevated surface temperatures were identified in satellite images during 21-23 March. The Aviation Colour Code remained at Orange and the Volcano Alert Level remained at Warning.

Cleveland | Chuginadak Island (USA) : A small explosion at Cleveland was detected in both seismic and infrasound data at 0815 on 24 March, prompting AVO to raise the Aviation Color Code to Orange and the Volcano Alert Level to Watch. Cloud cover at 9.1 km (30,000 ft) a.s.l. obscured satellite observations of the volcano, and no ash cloud was observed from this event. Cloud cover prevented views during 25-27 March, and slightly elevated surface temperatures were identified in satellite data during 27-28 March; nothing significant was detected in seismic or infrasound data.

Colima | Mexico : On 24 March the Centro Universitario de Estudios e Investigaciones de Vulcanologia - Universidad de Colima reported that during the previous week the seismic data revealed 70 high-frequency events, 25 long-period events, over one hour of tremor, four landslides, and four low-intensity explosions. The sulphur dioxide flux was 11-74 tons/day, reflecting low volcanic activity.

Dukono | Halmahera (Indonesia) : Based on analyses of satellite imagery, wind model data, and notices from PVMBG, the Darwin VAAC reported that during 22-28 March ash plumes from Dukono rose to an altitude of 2.1 km (7,000 ft) a.s.l. and drifted in multiple directions.

Ebeko | Paramushir Island (Russia) : KVERT reported that during 20-22 March several explosions at Ebeko, observed by residents of Severo-Kurilsk (Paramushir Island) about 7 km E, generated plumes that rose to altitudes of 1.7-1.8 km (5,600-5,900 ft) a.s.l. Minor amounts of ash fell in Severo-Kurilsk on 21 March. The Aviation Colour Code remained at Orange (the second highest level on a four-colour scale).

Fuego | Guatemala : INSIVUMEH reported that during 25-28 March explosions at Fuego generated ash plumes that rose as high as 1.1 km above the crater rim and drifted 10-12 km SW and S. Ashfall was reported in areas downwind including Panimaché I and II (8 km SW), Morelia (9 km SW), Santa Sofía (12 km SW), Los Yucales, and El Porvenir. Shock waves and rumbling from the explosions were sometimes heard; structures in local areas were rattled from explosions during 26-27 March. Incandescent material was ejected as high as 300 m above the crater rim, and sometimes landed 250 m away. Avalanches of material were confined to the crater. INSIVUMEH noted that activity had become more intense on 27 March.

Kilauea | Hawaiian Islands (USA) : During 22-28 March HVO reported that the lava lake continued to rise, fall, and spatter in Kilauea’s Overlook crater. A small collapse of the S part of the crater wall at 0035 on 23 March was followed by a short time of increased spatter.

Webcams recorded incandescence from long-active sources within Pu'u 'O'o Crater, from a vent high on the NE flank of the cone, and from a small lava pond in a pit on the W side of the crater. The 61G lava flow, originating from a vent on Pu'u 'O'o Crater's E flank, continued to enter the ocean at Kamokuna from the end of the lava tube, about 20 m above the water; the ocean entry was not consistently visible during the week. Surface lava flows were active above the pali, with most of the activity located 1.9-2.9 km from the 61G vent. During 24-25 March HVO noted that a delta had begun to form at the ocean entry, for the first time since the previous one had collapsed on 31 December 2016.

Klyuchevskoy | Central Kamchatka (Russia) : On 24 March KVERT reported that gas-and-steam emissions continued to rise from Klyuchevskoy's crater, and a weak thermal anomaly was occasionally identified in satellite images. The Aviation Colour Code was lowered to Green (the lowest level on a four-colour scale). On 28 March a gas, steam, and ash plume identified in satellite data rose to altitudes of 5-6 km (16,400-19,700 ft) a.s.l. and drifted 108 km ENE. The Aviation Colour Code was raised to Yellow. The next day an ash plume rose as high as 7.5 km (24,600 ft) a.s.l. and drifted 75 km SW. The Aviation Colour Code was raised to Orange.

Nevado del Ruiz | Colombia : Based on info from Servicio Geológico Colombiano’s (SGC) Observatorio Vulcanológico y Sismológico de Manizales, the Washington VAAC reported that on 26 March ash plumes from Nevado del Ruiz rose to an altitude of 7 km (23,000 ft) a.s.l. On 27 March the observatory reported that at 1029 a gas-and-ash plume rose 1.6 km above the crater rim and drifted E. The emission was associated with a seismic event and was also recorded by a webcam.

Pacaya | Guatemala : In a special report from 24 March INSIVUMEH noted that lava fountains 25-50 m high rose from a new cone forming in the crater of Pacaya’s Mackenney’s cone. The accumulated material had been filling up the cone, causing lava to flow through the crater breach formed in 2010. During 25-28 March small Strombolian explosions ejected material as high as 30 m above the cone.

Sabancaya | Peru : Based on webcam images, satellite views, and seismic data the Buenos Aires VAAC reported sporadic gas-and-ash puffs from Sabancaya during 24-27 March, sometimes rising as high as 9.1 km (30,000 ft) a.s.l. Weather clouds often hindered observations of the volcano, especially during 22-3 and 25 March.

Sheveluch | Central Kamchatka (Russia) : KVERT reported that during 17-24 March lava-dome extrusion onto Sheveluch’s N flank was accompanied by strong fumarolic activity, dome incandescence, ash explosions, and hot avalanches. Satellite images showed a daily thermal anomaly over the dome, and ash plumes that drifted 126 km WNW on 19 and 21 March. The Aviation Color Code remained at Orange (the second highest level on a four-colour scale).

Sinabung | Indonesia : Based on PVMBG observations, satellite data, and wind data, the Darwin VAAC reported that during 22, 24-25, and 27 March ash plumes from Sinabung rose to altitudes of 3.3-4.3 km (11,000-14,000 ft) a.s.l. and drifted S, SE, and E.

Suwanosejima | Ryukyu Islands (Japan) : Based on JMA notices and satellite-image analyses, the Tokyo VAAC reported that on 28 March an explosion at Suwanosejima generated a plume that rose to an altitude of 1.8 km (6,000 ft) a.s.l. and drifted SE.

Turrialba | Costa Rica : OVSICORI-UNA reported that a weak ash emission from Turrialba was visible during 1800-1940 on 25 March. Periods of more intense crater incandescence, from possible Strombolian activity, corresponded to higher tremor amplitude during 0330-0530 on 26 March. Later that day a small plume with a minor amount of ash rose 500 m above the crater and drifted S and SE. An event at 0752 on 28 March generated an ash plume that rose 300 m and drifted S.

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