Preparedness and Planning Volcano

eruption which devastated the town of Chaiten and how its poor preparation influenced this. Also I will discuss the 1991 eruption of Mount Etna in Sicily and how its preparedness and planning has on it as one of the world’s best monitored and controlled volcanoes.

On the 2nd May 1991 a Chilean volcano that had laid dormant for nearly 9000 years exploded into eruption. Due east winds carried the huge ash column east. However due to the size of the column (20-30 km in height) the town of Chaiten, 10km south west of the volcano, was largely affected. Due to its 9000 years of dormancy, the Chilean volcanic society had not deemed it dangerous enough to be actively monitored prior to the eruption as limited research and funding was available to their one volcanic acquisition centre even though there was documented history of dome column building and collapse. The rhyolitic nature of the volcano (commonly found on destructive margins) meant that the volcano’s eruption has increased by 500000m2 and created 50 million m3 of new material. The subsequent collapse of the column caused pyroclastic flows down the volcano’s slopes. It was only on the 16th May when the USGS arrived was the volcano actively monitored. However due to the extensive eruption creating thunderstorms due to high execution of gases and the passing of a storm, rainfall mixed with the ash fall (15cm in some places) generated lahars which flowed down into the town of Chaiten.

UN government officials reported that 90% of the town was damaged and 20/30% of the town was completely destroyed. Despite this only 1 person died in this event. Due to poor planning the town of Chaiten was almost destroyed. If effective and appropriate land zoning techniques were enforced