And Their Effects
By Maura Quinn and Max Stallop
Places Most Vulnerable
to Volcanic Activity
The areas most vulnerable to volcanic activities are areas along tectonic plates, particularly those around the Pacific plate as can be seen by the map above. However, not all of these are necessarily still active today. Recent volcanic eruptions since 2000 can be seen on the map below, though it is by no means comprehensive.
Processes That Increase These Areas' Vulnerability
There are no human processes that have led to the increased vulnerability of the areas mapped above. The vulnerability comes solely from tectonic activity. Volcanoes are created by convergent or divergent plate boundaries, and the eruptions from pressure caused by building pressure of magma pushed up by the movement of the plates. The diagram below shows how physical processes, in this case a convergent plate boundary, can create volcanoes.
Life and Property Costs
Between 1980 and 2008, 25,197 were killed because of volcanoes, averaging 869 deaths per year. Economic costs in the same time frame was $2,870,769,000 USD, $98,992,000 USD each year. But these are averages. Some volcanoes are in more isolated areas, or so that the costs of its eruption are limited. The other end of the outliers though can have much more prominent effects. For example, a Columbian eruption in 1885 killed 21,800 people, caused $1,000,000,000 and affected hundreds of thousands more people.
Adaptations and Preperation for Vocanic Activity
While volcanic eruptions cannot be prevented, they can be predicted by watching for warning signs, many small earthquakes and rising temperatures in the vacinity of the volcano, and closer to the actual eruption, the release of gasses with increasingly high sulfur content. The cartoon above shows these and several other techniques used to predict volcanic eruptions. Knowing when it will happen is only the first step. Residents of these areas have adopted the following techniques to prepare: creating an exclusion zone, having an evacuation plan, being ready with basic supplies and provisions, as shown in the picture below, and a good communication system. Evacuation is key.
"Lateral blasts" are sideways volcanic eruptions. These result in large pieces of rocks being launched from the volcano at very high speeds and can travel for several miles. They are as deadly as their vertical counterparts, killing through impact, burial or heat. They have enough power to be able to knock down entire forests. The first picture below shows a lateral blast in progress, the second shows the forest decimated by Mt St Helens lateral blast.