Smithsonian/USGS Weekly Volcanic Activity Report 15-21 June 2011 23 June 2011Posted by admin in activity reports, Africa, Batu Tara, Chile, Costa Rica, Egon, Eritrea, eruptions, Etna, Hawaii, Indonesia, Italy, Kamchatka, Karymsky, Kilauea, Nabro, Paluweh, Russia, Shiveluch, Turrialba, United States, Weekly Volcanic Activity Reports.
Tags: Global Volcanism Program
The Smithsonian Institution and United States Geological Survey Weekly Volcanic Activity Report, compiled by Sally Kuhn Sennert, has been issued for the week 15-21 June 2011. Some of the highlights:
- Etna: renewed ash emissions from Bocca Nuova
- Nabro: eruption continues, with plumes of water vapour and sulphur dioxide
- Puyehue-Cordón Caulle: a viscous lava flow observed as eruptive activity continues
- Turrialba: a new crater lake observed at the summit
Click on the map for a larger version (1211 x 784 pixels).
The Smithsonian Institution/United States Geological Survey Weekly Volcanic Activity Report for 15-21 June 2011 is now available on the Global Volcanism Program website. The following is a summary and not a substitute for the full report.
- The current report: Weekly Volcanic Activity Report.
- Previous reports: Weekly Reports Archive.
- The SI/USGS map of volcanoes discussed this week.
New activity/unrest: Etna (Italy), Nabro (Eritrea), Puyehue-Cordón Caulle (Chile), Turrialba (Costa Rica).
Ongoing activity: Batu Tara (Indonesia), Egon (Indonesia), Karymsky (Russia), Kilauea (Hawaii, USA), Paluweh (Indonesia), Shiveluch (Russia).
Note: ‘a.s.l.’ = ‘above sea level’.
Etna (Italy). Sezione di Catania – Osservatorio Etneo reported that on 13 June mountain guides heard loud hissing sounds coming from the interior of Etna’s Bocca Nuova crater. After nearly six months of quiescence, ash emissions rose from Bocca Nuova the next morning. The emissions were composed of small ash clouds that seemingly originated from the central part of the crater and rose about 200-250 m above the crater rim, then drifted E. Thermal monitoring cameras showed no signs of incandescence in the emissions, which were observed for a few hours before meteorological clouds moved in and prevented further observations. During limited periods of good visibility from 15 to 17 June, sporadic small reddish-to-greyish-brown ash plumes were observed to occur every 5-15 minutes. Usual rhythmic emissions of gas and vapour from the Northeast Crater continued. [GVP: Etna]
Nabro (Eritrea). An eruption from Nabro that started on 12 June continued to produce a plume. Based on analyses of satellite imagery, the Toulouse VAAC reported that during 15-20 June plumes comprised mostly of water and sulfur dioxide rose to altitudes of 6.1-7.9 km (20,000-26,000 ft) a.s.l. Ash was occasionally detected near the volcano. Satellite imagery posted on MODIS Web showed a dark brown ash plume fanning out to the SW on 19 June. A thermal satellite image acquired at night on 19 June revealed a 15-km-long lava flow that had traveled NW. A high-altitude plume, likely rich in water vapour, rose from the erupting vents and a diffuse ash-rich plume drifted SW. News articles stated that ash had covered a well-known mine that produces edible salt, and had contaminated food and water sources. During 15-16 June several airlines cancelled some domestic and international flights, including in and out of Addis Ababa (Ethiopia), neighboring Djibouti, and Khartoum (Sudan). [GVP: Nabro]
Puyehue- Cordón Caulle (Chile). OVDAS-SERNAGEOMIN reported that the eruption from the Cordón Caulle rift zone, part of the Puyehue-Cordón Caulle volcanic complex, that began on 4 June continued during 15-18 June. The seismic network detected small explosions on 15 June. The eruption plume rose 4-5 km above the crater and drifted SE. The base of the plume was dark grey and ash continued to fall in areas near the volcano. The next day the plume rose 3 km above the crater and was whiter. Satellite imagery showed the plume drifting 1,400 km ESE. On 17 June the plume rose 2 km above the crater and drifted SE. About 5 mm of ash had accumulated in Pajaritos during the night. Ashfall was also reported in eastern areas of Lago Rupanco, about 30 km SSW. According to news articles, plumes from the eruption had circumnavigated the globe, arrived in the W part of Chile (in Coyhaique, 550 km S of the volcano), and again caused domestic flights to be cancelled. On 19 June SERNAGEOMIN noted that weather prevented clear observations, although a thermal camera used during an overflight showed a thermal anomaly near the emission centre. The plume rose 2 km above the crater and drifted SE. A news article stated that authorities lifted the evacuation ban for area residents, allowing them to return home. Articles also stated that flights in South Africa were disrupted during 18-19 June. SERNAGEOMIN personnel along with regional authorities flew over Puyehue-Cordón Caulle on 20 June. They observed a viscous lava flow with concentric morphology, confirming speculation of magma ascent reflected in seismic data from the previous few days. A 50-m-wide lava flow from the emissions center had traveled 200 m NW and 100 m NE, filling up a depression. A white plume that was grey at the base rose 3-4 km above the crater. Devastated vegetation from pyroclastic flows was observed near the basin of the Nilahue and Abutment rivers. Pulses of tremor were detected by the seismic network. Cameras installed around the volcano showed the plume, which was periodically very dark, rising 5-6 km above the crater. On 21 June the plume rose 3-4 km above the crater and was dark at the base. Although there were no new aerial observations, the seismic signals indicated that the lava flow remained active. News reports noted that flights were again disrupted in parts of Australia on 21 June. SERNAGEOMIN reiterated that the Alert Level remained at 6, Red. [GVP: Puyehue-Cordón Caulle]
Turrialba (Costa Rica). OVSICORI-UNA reported that on 9 June scientists conducting fieldwork at Turrialba observed a new crater lake in the W crater, which opened in January 2010 and was the center of the most recent activity. Since February, rock landslides along with abundant mud and clay had accumulated in the bottom of the crater, blocking the vent. Meteoric water from rains starting in May had formed a light-green-coloured lake that was 70 by 70 m and about 1 m deep. Minor bubbling in the SW and NE shores was noted, and steam and sulphur dioxide gas emissions rose from many fumarolic vents around the crater. [GVP: Turrialba]
Batu Tara (Indonesia). Based on analyses of satellite imagery, the Darwin VAAC reported that during 16-20 June ash plumes from Batu Tara rose to an altitude of 2.4 km (8,000 ft) a.s.l. and drifted 55-75 km W, NW, and N. [GVP: Batu Tara]
Egon (Indonesia). CVGHM reported that on 17 June the Alert Level for Egon was lowered to 1 (on a scale of 1-4) because seismicity had decreased and emission heights had been lower since January. [GVP: Egon]
Karymsky (Russia). KVERT reported moderate seismic activity at Karymsky during 10-16 June and that possible ash plumes rose to an altitude of 5.5 km (18,000 ft) a.s.l. Satellite imagery showed a weak thermal anomaly on the volcano during 10-14 June and an ash plume that drifted 90 km NE on 14 June. The Aviation Colour Code remained at Orange. [GVP: Karymsky]
Kilauea (Hawaii, USA). HVO reported that two lava lakes at Kilauea were active during 15-21 June. The level of the summit lava lake fluctuated but remained mostly stable deep in the vent inset within the E wall of Halema’uma’u Crater. A gas plume from the vent drifted SW, depositing variable amounts of ash and fresh spatter nearby. On 17 June a heated brown plume rose from a spattering source on the SE edge of the lake; the ejecta were primarily fresh spatter bits suggesting that the plume derived from a partial collapse of the spattering source or a small rockfall. At Pu’u ‘O’o, lava from vents near the W and NE edges of the perched lava lake in the center of the crater floor continued to fill the lake. The lake level fluctuated and overflowed the edges or flowed through rim breaches, sending lava onto the Pu’u ‘O’o crater floor. A small shield had built up against the SW crater wall on the W side of the lake. There was also minor lava activity from at least one source at the base of the SW crater wall. [GVP: Kilauea]
Paluweh (Indonesia). CVGHM reported that volcanic tremor from Paluweh had not been detected since 1 March 2010 and during January 2011-June solfatara emissions from the summit were not observed. On 17 June, the Alert Level was lowered to 1 (on a scale of 1-4). [GVP: Paluweh]
Shiveluch (Russia). KVERT reported moderate seismic activity at Shiveluch during 10-16 June and that possible ash plumes rose to an altitude of 10 km (32,800 ft) a.s.l. on 15 June. Satellite imagery showed a gas-and-steam plume drifting 26 km NW on 10 June and a thermal anomaly on the lava dome during 10 and 12-13 June. Meteorological clouds prevented observations on the other days. The Aviation Colour Code remained at Orange. Based on information from KVERT and analyses of satellite imagery, the Tokyo VAAC reported that eruptions on 20 June produced plumes that rose to altitudes of 6.7-10.1 km (22,000-33,000 ft) a.s.l. [GVP: Shiveluch]
The foregoing is a summary of the Smithsonian Institution/United States Geological Survey Weekly Volcanic Activity Report covering 15-21 June 2011. It is provided for information only, and is based on but not a substitute for the full report, which comes with its own criteria and disclaimers. The map base is derived from the Smithsonian Institution/USGS/US Naval Research Laboratory This Dynamic Planet website.
For all our coverage of the SI/USGS Weekly Volcanic Activity Reports: Weekly Volcanic Activity Reports « The Volcanism Blog.