Friday, 7 July 2017

Volcanos

Roundup of Global Volcanic Activity - Ongoing Activity for the week of 28 June - 4 July 2017

Aira | Kyushu (Japan) : JMA reported that events at Showa Crater (at Aira Caldera’s Sakurajima volcano) at 1811 and 1904 on 27 June generated ash plumes that rose 1 km above the crater rim. Weak incandescence from the crater was noted on 30 June. During 30 June-3 July there were five events, one of which was explosive. Material was ejected as far away as 500 m from the crater. 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 on 2 July an ash plume from Bagana drifted W at an altitude of 2.1 km (7,000 ft) a.s.l.

Bezymianny | Central Kamchatka (Russia) : KVERT reported that incandescence from Bezymianny's lava dome was observed at night during 23-30 June, and a lava flow continued to flow down the W flank of the dome. A thermal anomaly was identified daily in satellite images. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Cleveland | Chuginadak Island (USA) : A moderate 10-minute-long explosion at Cleveland was detected in both seismic and infrasound data beginning at 0319 on 4 July, prompting AVO to raise the Aviation colour Code to Orange and the Volcano Alert Level to Watch. After the event, seismicity declined and remained low. Satellite images showed no clear evidence of an ash plume.

Copahue | Central Chile-Argentina border : OVDAS-SERNAGEOMIN reported that during 5-15 June the seismic network at Copahue detected long-period earthquakes. Gas plumes constantly rose from El Agrio crater and on several days contained ash. The highest plume, detected on 5 June, rose 300 m and drifted E. The Buenos Aires VAAC reported that on 1 July the webcam recorded a steam-and-gas plume with minor ash near the summit. The Alert Level remained at Yellow (the second lowest on a four-colour scale); SERNAGEOMIN recommended no entry into a restricted area within 1 km of the crater.

Dukono | Halmahera (Indonesia) : Based on analyses of satellite imagery, wind model data, and notices from PVMBG, the Darwin VAAC reported that during 28 June-4 July ash plumes from Dukono rose to an altitude of 2.1 km (7,000 ft) a.s.l. and drifted E, ESE, and S.

Ebeko | Paramushir Island (Russia) : Based on observations by residents of Severo-Kurilsk (Paramushir Island), about 7 km E of Ebeko, explosions during 23-30 June generated ash plumes that rose as high as 2 km (6,600 ft) a.s.l. Ashfall was reported in Severo-Kurilsk on 24 and 26 June. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Kilauea | Hawaiian Islands (USA) : During 28 June-4 July HVO reported that the lava lake continued to rise, fall, and spatter in Kilauea’s Overlook crater. 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 (which had many small spattering sites along the margin) 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. A solidified lava ramp extended from the tube exit high on the sea cliff down to the growing delta, whose leading edge was about 100 m from the tube exit on the sea cliff.

Klyuchevskoy | Central Kamchatka (Russia) : KVERT reported that during 22-24 and 27-28 June a weak thermal anomaly was identified in satellite images at Klyuchevskoy. Explosions on 24 and 26 June generated ash plumes that rose to 5-6 km (16,400-19,700 ft) a.s.l. and drifted 112 km S and SE. 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 21 June ash plumes from Langila rose 2.1 km (7,000 ft) a.s.l. and drifted almost 95 km NW.

Nishinoshima | Japan : Based on satellite images, pilot observations, and information from JMA, the Tokyo VAAC reported that during 30 June-2 July ash plumes from Nishinoshima rose 1.5-3 km (5,000-10,000 ft) a.s.l. and drifted W and E.

Poas | Costa Rica : OVSICORI-UNA reported low-to-moderate-amplitude tremor with occasional periods of high-frequency volcano-tectonic events detected at Poás during 28-29 June. Webcams recorded intense incandescence at night from the bottom of the crater. A sulfur odor was noted in San Rafael de Poás and Vara Blanca. An event at 1115 on 19 June generated a plume that rose 1 km above the vents. An event at 1450 may have generated a plume, but poor visibility did not allow for confirmation. During 1-4 July frequent but small Strombolian activity ejected incandescent material that fell around vent “A” (Boca Roja). Plumes of water vapor, magmatic gases, and particulates rose at most 500 m from the vents.

Popocatepetl | Mexico : Each day during 28 June-4 July CENAPRED reported 67-240 and steam and gas emissions from Popocatépetl, some of which contained minor amounts of ash. Explosions were detected on 28 June (4), on 30 June (1), on 2 July (5), and on 3 July (1), though cloudy conditions prevented visual confirmation of possible ash, gas, and steam plumes. Minor ashfall on 2 July was noted in Ozumba, Amecameca, Tlalmanalco, Chalco, Ayapango, Tenango del Aire, and San Pedro Nexapa. An explosion at 1145 on 4 July generated an ash plume that rose 2.5 km above the crater rim and drifted W. 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 continued to decline; there was an average of five explosions recorded per day during 26 June-2 July. The explosions were also less energetic. Gas-and-ash plumes rose as high as 1.5 km above the crater rim and drifted more than 30 km SE. Sulfur dioxide flux was as high as 1,472 tons per day, recorded on 1 July.

Sinabung | Indonesia | 3.17°N, 98.392°E | Elevation 2460 m

Based on PVMBG observations, satellite images, and wind data, the Darwin VAAC reported that during 29 June-3 July ash plumes from Sinabung rose 3.3-4.9 km (11,000-16,000 ft) a.s.l. and drifted ESE.

Suwanosejima | Ryukyu Islands (Japan) : Based on JMA notices and satellite-image analyses, the Tokyo VAAC reported that on 2 July ash plumes from Suwanosejima rose to altitudes of 1.8-2.4 km (6,000-8,000 ft) a.s.l. and drifted N.

Turrialba | Costa Rica : OVSICORI-UNA reported that during 29 June-4 July seismicity at Turrialba was characterized by low-to-medium amplitude tremor, and a small number of low-amplitude volcano-tectonic and long-period events. Plumes of water vapor, magmatic gases, and occasional ash rose as high as 1 km above the West Crater fumaroles. Incandescence from the main crater was recorded at night. Minor ashfall and a sulfur odor was reported in areas of San José including Rancho Redondo, Goicoechea, Moravia, San Pedro Montes de Oca, and Guadalupe.

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