If you have ever feared visiting a volcano or its surroundings due to the risks it can entail, you may wonder how you can distinguish one that is active from another that remains inactive. We have some bad news for you: there is no way to know for sure if a volcano just erupted or if it will soon .
This can be highly dangerous, since the geographical surroundings of the volcanoes are characterized by incredibly fertile soils , which has led many communities throughout history to settle in these types of areas. In fact, when the Yellowstone, Toba and Vesuvius catastrophes took place, it was fairly safely believed that these volcanoes were not going to erupt, since they had not exploded for a long time.
The only way to know if a volcano is active or inactive is to trust the periodicity with which it erupts . If you do it regularly, it is considered an active volcano; if it has not exploded for centuries, inactive. Scientists often call a volcano active if it shows signs of upheaval (that is, unusual seismic activity or significant new gas emissions) that suggest that it is about to erupt, but there is not even consensus among vulconologists on this. .
The Smithsonian Global Volcanism Program, for example, considers that a volcano that has erupted in the last 10,000 years remains active. For its part, the International Association of Volcanology considers the more than 500 volcanoes that have erupted in the course of human history to be active, a somewhat fragile measure, since not the entire history of humanity has been recorded and documented.
In general, if you have been expelling lava regularly, if you are currently expelling it or it is anticipated that you may expel it in the near future, a volcano is active, without further discussion. And those that are considered inactive will likely erupt again in the future. Finally, other volcanoes can be considered extinct when they have run out of magma supply , but this is something very difficult to determine, since the life of a volcano that can erupt … it can even last millions of years!
