People have a knack to read up on extinction events, after all not much is known about the event that killed off the dinosaurs a few million years ago. 

With the Yellowstone Caldera being one of the deadliest supervolcanoes in existence, we ought to be prepared. But we may be preparing for the wrong supervolcano.

According to Science Alert, supervolcanoes are in reality extensive fields of volcanic activity. These are formed when a volcano ejects too much magma from its center that it collapses in itself, leaving a large crater and a landscape with geysers, hydrothermal activity, and sulphuric acid.

Campi Flegrei -- or burning fields, in Italian -- is another one of these areas in Naples, Italy. It has 24 craters and large volcanic edifices, mostly under the Mediterranean Sea. This ancient "caldera" or cauldron-like depression formed 39,000 years ago as part of the biggest eruption Europe has seen in 200,000 years.

The place has had only two major eruptions, one 35,000 years ago and 12,000 years ago, and a smaller one in 1538.

Although of course "smaller" is relative, given it lasted for eight days straight and formed a new mountain, Monte Nuovo.

However, it's the entire site that is the concern. The eruption 200,000 years ago is thought to have been so cataclysmic, it triggered "volcanic winter," which ultimately led the Neanderthals to be extinct.

According to Nature, a team of volcanologist Giovanni Chiodini from the Italian National Institute of Geophysics in Rome reports that Campi Flegrei appears to be approaching a critical level - as in a dangerous pressure point that can trigger eruption.

According to the Washington Post, this is called the critical degassing pressure, and could drive volcanic unrest towards a critical state by releasing jets of super-hot gas into the atmosphere. 

This can cause the heating of hydrothermal fluids and rocks and even cause rock failure and an eruption.

The study added that the Campi Flegrei has been experiencing an "uplift," suggesting the volatile gases beneath are rising to the surface at an accelerating rate.

Two other active volcanoes - Rabaul i nPapua New Guinea and Sierra Negra in the Galapagos - have showed acceleration in ground deformation before eruption with a pattern similar to Campi Flegrei. 

So is this a cause of alarm? Not yet, because it's pretty much impossible to predict what the volcano can do at this point - if it will do anything at all.