Now I'm sure we all know what a volcano is, so I'm not going to go on & on about it. Instead, I'm going to give you a few, interesting facts.
- lava = magma that has reached the surface & been exposed to air
- volcanoes form where the tectonic plates (the large “pieces” that form the Earth) are pulling apart or are coming together (not necessarily where the plates slide past each other, which is a cause of earthquakes)
- not all volcanoes spew lava - and even if they do, this isn't necessarily the most dangerous aspect of a volcanic eruption
- as we saw with the recent Icelandic eruption, ash can be released, having a huge impact on air quality & visibility
- mud slides can triggered, and entire sections of the volcano can go slipping down the mountainside (as was the case with Mount Ste Helens)
- volcanoes are often thought to be in tropical regions, but they can be found in colder regions as well (like Iceland) – here, they can cause major flooding if the volcano is near a glacier
- many toxic gases and particulates, including hydrogen sulfide, are also released into the air – these can be trapped in the upper atmosphere, having prolonged & widespread consequences
- the volcano Vesuvius in Italy erupted in 79 AD. The prevailing winds caused the ash expelled to be dumped on Pompeii. The nearby town of Herculaneum, in contrast, was hit with the brunt of the pyroclastic flow – hot gases & rock that quickly buried the city. Both cities were perfectly preserved because of this & still being excavated today!
- volcanoes will sometimes erupt in tandem – volcanoes are often clustered together, and will erupt together (or within a few decades of each other)