Large-scale eruption of Italy's supervolcano could impact global climate

The volcanic area west of Naples, Italy, known as Phlegrean Fields, is stirring with early signs of a new caldera cycle for one of the world's most menacing supervolcanoes, according to new research.

Scientists are concerned a "potential reawakening" of the volcano is in store, according to a new study published in Science Advances.

The largest known eruption of Phelgrean Fields, also called Campi Flegrei, occurred 200,000 years ago, darkening skies across Europe with volcanic ash. The eruption of Campi Flegrei, which means "Burning Fields" in Italian, led to significant changes in the global climate.

According to a 2010 study published in Current Anthropology, it is likely the powerful eruption of Campi Flegrei played a role in the extinction of Neanderthals amid the ensuing volcanic winter.

In addition, the volcano has shown signs of unrest in recent history as early as the 1950s.

"Three major periods of unrest characterized by shallow seismicity and an increase in hydrothermal degassing have been recorded since the 1950s, thus increasing concern for a potential reawakening," the study stated.

"Located in one of the most populated regions on Earth, Campi Flegrei is an active and restless volcano that has produced two cataclysmic caldera-forming eruptions and numerous smaller eruptive events over the past 60,000 years," the study stated.

Griggs J.D. USGS

Lava moves across the ground as a pahoehoe flow, Kīlauea Volcano, Hawai'i

The research focused primarily on the long-term evolution of volcanic activity in the region, while past studies have focused more on specific periods of activity or single-eruption events.

The authors used "textural information" such as rock, mineral and glass samples from nearly two dozen eruptions at Camp Flegrei.

"Caldera-forming magmatic systems often follow recurrent evolutionary paths, [or caldera cycles] accompanied by notable changes in the composition and physical properties of erupted magmas, frequency, spatial distribution and size of volcanic eruptions," the authors reported.

The team's research revealed potential of a new caldera cycle, which could mean a building period of magma, subsequent eruptions and eventually a collapse of the caldera, according to the report.

"After the Monte Nuovo eruption, the Campi Flegrei caldera has entered a new phase of [quietness] accompanied by several episodes of ground deformation," the authors said.

While it is unknown when another eruption will occur or how large it will be, another large-scale event could not only devastate the highly populated area near the caldera but also lead to a volcanic winter and changes to the global climate as large amounts of ash enter the atmosphere.

"Home to more than 1.5 million people, the Campi Flegrei caldera represents one of the most hazardous regions on Earth, and its magmatic history has been the focus of a number of studies," the study said.

AccuWeather Senior Meteorologist Jim Andrews said a powerful volcanic eruption could have a detrimental effect on the global climate if conditions were severe enough.

"It's widely believed by researchers that when you have a tremendous volcanic blast that lofts ash and gas into the stratosphere, you get a reflection of sunlight before it gets deep enough into the atmosphere," Andrews said.

"Effectively, you're losing heat energy, and if it's powerful enough and spreads a cloud around the equator, you're losing a tremendous amount of solar energy."

The stronger the volcanic blast is, the more intense the result will be, Andrews said.

"The higher sulfur dioxide content, the better, and the nearer to the equator it is, the better," he said. "It's going to put that cloud right in the wheelhouse of the climate, where the rubber meets the road."

Tambora was the site of the largest volcanic eruption in the last 10,000 years and contributed to a cold year in 1816, which has been called the "Year Without a Summer."

Unseasonably cold weather killed trees, rice and water buffalo in China and Tibet while floods destroyed the remaining crops, leading to famine in the region. In addition, growing seasons were also afflicted in the Northern Hemisphere across Europe and North America.

In the northern United States, even Thomas Jefferson's crop was plagued by the harsh chill that continued well into the summer with a Virginia snowfall in June.

The Italian supervolcano is also similar to the one the lies dormant under Yellowstone National Park. It is comprised of a complex network of volcanic features including 24 craters, geysers and volcanic vents that spew hot gases.

The most recent notable eruption in the region occurred in 1538, but it was small in comparison to two other events that occurred 12,000 and 30,000 years ago.

If the Yellowstone volcano was to erupt today, the effects would also be similar.

"Such a giant eruption would have regional effects such as falling ash and short-term [years to decades] changes to global climate," the U.S. Geological Survey reports.