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Activity at Etna: an update 18 May 2008

Posted by admin in activity reports, eruptions, Etna, Italy.
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The ongoing eruption at Chaitén has tended to exercise a near-monopoly over the attention of volcano-watchers lately, but there has been much of volcanological interest going on elsewhere. Mount Etna, for a start, has been having an active time of it over the last few weeks.

After a quiet period of some seven months, Etna resumed activity with increased seismic activity and intermittent explosive activity of strombolian character between 21 and 28 April from a fissure on the eastern flank of the South East Crater at the summit.

From 21:00 local time on 1 May swarms of earthquakes were recorded along the north-eastern rift zone, and significant degassing took place at the South East Crater and North East Crater.

On 10 May between 13:00 and 14:00 UTC an increase in the intensity of tremors at the volcano indicated resumption of eruptive activity, although poor visibility prevented direct observation. The eruption involved strong strombolian activity at the South East Crater and lava emission (lava flows advanced about 6.4km along the western side of the Valle de Bove), and lasted to the early evening when seismic activity returned to normal background levels and the eruption ceased. Ashfall was reported from multiple locations during 10-11 May.

13 May saw powerful seismic signals and explosive activity in the early morning. Several powerful earthquakes were recorded and a significant thermal anomaly was recorded at the summit. A plume of ash was emitted around 11:30 which was blown towards the north-east of Sicily and Calabria: ashfall was reported in several villages in north-eastern Sicily. A significant eruptive fissure opened north-east of the South East Crater, between 2700 and 2900 metres above sea level. Sustained strombolian activity and the emission of a plume of ash was observed during the afternoon, although visibility remained poor. Repeated earthquakes on the north-eastern flank of the volcano indicated the migration of magma to this area.

Fumarolic activity continued into 14 May, with evidence of some effusive lava eruption from the new fissure. Visual observations on 14 May confirmed the appearance of not one but two new eruptive fissures, one just east of the summit craters and the other to the north-east of the South East Crater. From this latter opening lava flows were emerging, eventually extending for approximately 5 km.

The latest reports (17 May 2008) indicate that Etna is currently at low levels of seismicity and is producing strombolian activity and effusive lava flows from the two new fissures. Small ash-laden eruption plumes are reaching several hundred metres in altitude.

The current eruptive activity has posed no danger to life or property.

Sources for the above summary: Istituto Nazionale di Geofisica e Vulcanologia – Sezione di Catania, current activity bulletins; Global Volcanism Program, weekly volcanic activity reports for Etna; Activolcans, volcanic activity reports; news sources as listed below.

Information
Global Volcanism Program: Etna – summary information for Etna (0101-06=)
Istituto Nazionale di Geofisica e Vulcanologia – Sezione di Catania – INGV-CT is the volcanological authority responsible for Etna; current activity reports are here
Toulouse Volcanic Ash Advisory Centre – volcanic ash advisories for the area that includes Etna

News
Eruptions subside at Sicily’s Mount Etna – AFP, 11 May 2008
Etna volcano rumbles back to life in Sicily – AFP, 13 May 2008
Etna: INGV, vulcano ‘buono’ ma attenti a meccanismi inediti – AGI News, 13 May 2008 (Italian)
Mount Etna flows back to life – BBC News (video), 14 May 2008
Eruzione Etna: continua l’attività eruttiva, le colate sono ancora alimentateTempo Stretto, 15 May 2008 (Italian)

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