There are few things in nature as fascinating as volcanoes. There are also few things that are as deadly. There are regular old volcanoes, and there are super-volcanoes. Super-volcanoes have the capacity to wipe out civilization, and one such super-volcano in Italy appears to be waking from a 500-year slumber. 
Rumored to have caused the extinction of the Neanderthals, the nearly 5-mile wide Campi Flegrei super-volcano sits on the Italian coast. Researchers are concerned that it is approaching a critical pressure point that could lead to an eruption. There are close to 500,000 people living around it.
When you picture a volcano, you picture smoke and lava erupting from its peak. But super-volcanoes are quite different. Imagine Yellowstone National Park. Super-volcanoes are formed when a volcano ejects so much magma from its center that it actually collapses on itself, leaving behind extensive fields of volcanic activity, a vast crater, as well as numerous geysers, hydrothermal activity, and sulphuric acid.
The Campi Flegrei super-volcano is made up of 24 craters and large volcanic edifices, many of which are submerged beneath the Mediterranean Sea. It formed 39,000 years ago, as part of the largest eruption Europe has experienced in the last 200,000 years.
Since its formation, Campi Flegrei has experienced 2 major eruptions – 35,000 years ago, and 12,000 years ago. A smaller eruption occurred in 1538. That “smaller” eruption, however, lasted for 8 days and spewed so much material into the surrounding area, it formed a new mountain, Monte Nuovo.
You get the point – even a “small” eruption is a huge event, so a major eruption could be catastrophic.
The eruption that occurred 200,000 years ago is believed to have triggered a “volcanic winter” that wiped out the Neanderthals. That’s pure speculation, but scientists say the eruption spewed some 1 trillion gallons of molten rock onto the surface and just as much sulphur into the atmosphere.
The Critical Pressure Point
A team of researchers from the Italian National Institute for Geophysics and Volcanology are watching Campi Flegrei very closely because the super-volcano appears to be approaching a critical pressure point that could trigger a 3rd major eruption.
“This critical pressure point – referred to as critical degassing pressure (CDP) – could drive volcanic unrest towards a critical state, the team reports, by releasing jets of super-hot gas into the atmosphere, heating the surrounding hydrothermal fluids and rocks, and causing rock failure and possibly an eruption.”
Volcanologist Giovanni Chiodini says:
“Hydrothermal rocks, if heated, can ultimately lose their mechanical resistance, causing an acceleration towards critical conditions.”
Campi Flegrei has been experiencing an “uplift” for the past decade, which suggests that the volatile gases beneath it are rising to the surface at an accelerating rate. This has prompted Italian authorities to raise the super-volcano’s alert level from green (“quiet”) to yellow (“requires scientific monitoring.”)
Uplift has signaled volcanic eruptions in the past, most notably with Rabaul in Papua New Guinea and Sierra Negra in the Galapagos.
No one is telling local residents to run for their lives just yet, because it is impossible to predict what, if anything, Campi Negrei might do. Chiodini says:
“We have many uncertainties and long-term previsions are at the moment not possible! For example, the process that we describe could evolve in both directions: toward pre-eruptive conditions or to the finish of the volcanic unrest.”
Chiodini and his team hope that their latest observations will spur other researchers to monitor Campi Flegrei in the coming years, so people have some idea of just how catastrophic another major eruption could be.
Problems in Peru
On December 26, at 8:24 a.m., the Sabancaya volcano, which sits just 40 miles from Peru’s second most populous city, Arequipa, began spitting smoke and ash some 11,500 feet into the air just over a week after it became active.
Local authorities have warned the local inhabitants that they are likely to be affected by the ash from the 20,000-foot volcano, whose name translates to “tongue of fire” in the local dialect of Quechua.
Sabancaya had been dormant for 200 years until it began erupting in the 1980’s.
Just 60 miles away, the Ubinas volcano is also in the midst of spewing smoke and ash 2 miles into the atmosphere. It is Peru’s most active volcano, and was last active in April 2014. Ubinas had been dormant for about 40 years before rumbling back to life in 2006.
Authorities began evacuating the surrounding area earlier this week.
Peruvian Geophysical Institute (IGP) investigator Orlando Macedo said:
“All this activity is part of an expected process. Before the eruption, tremors were occurring closer and closer to the volcano and the crater. However, the process is taking longer than that which we saw at the Ubinas Volcano, when everything happened in a matter of days. In the case of Sabancaya, this could go on for several months.”
Other Areas of Concern
There was a lot of moving and shaking in December 2016.
Mount St. Helens in Washington State experienced an earthquake “swarm” of some 120 shallow temblors over the course of several days. It is considered active, but an eruption could be years away. 
On the Kamchatka Peninsula in the Russian Far East, the Shiveluch volcano blew its top, destroying the small lava dome/plug in its crater and generating a 36,000-foot ash plume. Fortunately, the ash drifted to an uninhabited area, but an orange aviation alert was issued to warn airlines of the ash plume.
In Costa Rica, antennas on Irazu will have to be moved because of cracking on the volcano. It is unknown whether the cracking is related to any potential changes in the Irazu volcano, or if the surface blocks are just faulting.
The infamous Hawaiian volcano Kilauea experienced a small explosion, sending huge chunks of debris flying, including old wall rock and lava from the lava lake. This is a fairly common occurrence.
Lastly, scientists have noticed an increase in seismicity at Cayambe in Ecuador. An earthquake swarm that occurred there over several days in December indicate that Cayambe, like Mount St. Helens, is recharging, but no eruption appears to be imminent.
Julie Fidler is a freelance writer, legal blogger, and the author of Adventures in Holy Matrimony: For Better or the Absolute Worst. She lives in Pennsylvania with her husband and two ridiculously spoiled cats. She occasionally pontificates on her blog.