Question: How many years does it take a volcanoe erupt from the last time it erupted?

Philippa Demonte answered on 18 Jun 2011:

@hanniiee This is a great question, but there isn’t one specific answer. Every volcano is different, and so what’s called the repose time (the time between volcanic eruptions) is different for every volcano. The Hawaiian volcano Kilauea has been erupting constantly for almost 30 years now; Stromboli volcano near Italy erupts every few hours. Sometimes there are hundreds of years between eruptions for some volcanoes, or even hundreds of thousands of years. For example Yellowstone only erupts approximately every 640,000 years.

It all depends on the location of a volcano, for example volcanoes created by mantle plumes or where the tectonic plates are pulling apart, such as in Iceland, erupt fairly regularly, whilst volcanoes made from magma at subduction zones (where one tectonic plate goes under another) erupt less frequently, i.e. there are longer pauses between eruptions, but the eruptions at these volcanoes are much bigger and more explosiveMATOMO_URL

* Water is what makes certain volcanoes more explosive than others. When one tectonic plate subducts (is pulled) under another tectonic plate, it pulls down sea water with it. This causes the rocks within the Earth to melt at a lower temperature than normal to form magma and changes its composition so it’s much stickier. This makes it harder for the gases within the magma to escape, and so these volcanoes erupt more explosively.

I hope that makes sense. Volcanoes are quite complicated!