* Astronomy

On the 24 May the Colombian government ordered the evacuation of ~9,000 people living near the volcano Galeras due to an increased activity.
During 16-23 May, small shallow earthquakes occurred beneath the volcano. There was an increase in earthquakes associated with fracturing within the volcano during the night of 21 May to the morning of 22 May.
Gas emissions slightly decreased on 17 and 20 May in comparison to 29 April and 2 May, and slightly increased around 23 May.
Deformation continued to be recorded at the volcano's summit.
There were no ash emissions. Galeras remained at Alert Level 2 (probable eruption in terms of days or weeks) as it has since 19 April 2005.



Galeras has erupted more than 20 times since the 1500s. An eruption in January 1993 killed nine people on a scientific expedition to the volcano summit.

Galeras is a stratovolcano with a large breached caldera located immediately West of the city of Pasto, and is one of Colombia's most frequently active volcanoes.
The dominantly andesitic Galeras volcanic complex has been active for more than 1 million years, and two major caldera collapse eruptions took place during the late Pleistocene.
Long-term extensive hydrothermal alteration has affected the volcano.



This has contributed to large-scale edifice collapse that has occurred on at least three occasions, producing debris avalanches that swept to the West and left a large horseshoe-shaped caldera inside which the modern cone has been constructed.
Major explosive eruptions since the mid Holocene have produced widespread tephra deposits and pyroclastic flows that swept all but the southern flanks.
A central cone slightly lower than the caldera rim has been the site of numerous small-to-moderate historical eruptions since the time of the Spanish conquistadors.

Link:

.wmv news report

-- Edited by Blobrana at 16:34, 2005-05-26