Radiocarbon dating volcanic ash
It has erupted frequently since the Spanish conquest, with its first historical eruption being recorded on December 7, 1580.
A 1993 eruption killed nine people, including six scientists who had descended into the volcano's crater to sample gases and take gravity measurements in an attempt to be able to predict future eruptions.
As in 2005, the city of Pasto was blanketed by a layer of ash after the volcanic explosion (due to the direction of the wind).
The second some time between 40,000 and 150,000 years ago, in a smaller but still sizable eruption of 2 cubic kilometres (0.48 cu mi) of material.Other eruptions similar to this event include those in 3150 BC ± 200 years, 2580 BC ± 500 years, 1160 BC ± 300 years, 490 BC ± 100 years, and in 890 AD ± 200 years.Typically these eruptions consist of a central vent explosion, conducive to an explosive eruption causing pyroclastic flows and/or lahars.The Colombian government has repeatedly ordered evacuations to temporary shelters, of more than 8500 people residing in the highest risk areas surrounding the volcano, On January 17, 2008, the volcano erupted around (local) ( UTC).There were no immediate reports of injuries or serious property damage.
Search for radiocarbon dating volcanic ash:
However, the prediction was based simply on the one seismographic printout viewed in the light of previous history of Galeras, without any additional scientific measurements showing any serious activity within the volcano.