Rapid and Explosive Eruptions Possible From Dormant Volcanoes, New Study

Volcanoes are one of the most fascinating and powerful natural phenomena on our planet. They can create new islands, shape landscapes, and influence climate.

They can also pose serious threats to human lives and property, especially when they erupt unexpectedly and violently.

But how can we predict when a volcano will erupt? And what are the chances of a long dormant volcano suddenly waking up and unleashing its fury?

What is a long dormant volcano and why is it dangerous?

(Photo : KAREN MINASYAN/AFP via Getty Images)

A long dormant volcano is one that has not erupted for a very long time, usually thousands or tens of thousands of years.

Some examples of long dormant volcanoes are Mount Vesuvius in Italy, which last erupted in 79 AD, and Ciomadul in Romania, which last erupted around 30,000 years ago.

These volcanoes are often considered extinct, meaning that they have no chance of erupting again.

However, recent studies have shown that this is not always the case. Long dormant volcanoes can still have active magma chambers under them, which are reservoirs of molten rock that can rise to the surface and cause eruptions.

The problem with long dormant volcanoes is that they are very difficult to monitor and forecast.

Unlike active volcanoes, which show signs of activities, such as earthquakes, gas emissions, and ground deformation, long dormant volcanoes are often silent and invisible.

They can remain dormant for centuries or millennia, and then suddenly erupt without warning. This can catch people off guard and result in devastating consequences.

For example, the eruption of Mount Vesuvius in 79 AD buried the ancient cities of Pompeii and Herculaneum under ash and pumice, killing thousands of people.

The eruption of Mount Pinatubo in the Philippines in 1991, which was dormant for over 400 years, ejected millions of tons of ash and gas into the atmosphere, affecting global climate and causing widespread damage and displacement.

Also Read: Dormant Volcano in Alaska Shows Signs of Activity for the First Time in 800 Years, Could an Eruption be Underway?

How can we study long dormant volcanoes and assess their potential for eruption?

One of the ways to study long dormant volcanoes is to analyze their past eruptions and their magma composition.

By looking at the geological and historical records, we can learn about the frequency, magnitude, and style of their eruptions.

Scientists can also determine what type of magma they produce, and how it affects their explosiveness. For example, some magmas are more viscous and gas-rich than others, which makes them more prone to explosive eruptions.

Another way to study long dormant volcanoes is to use geophysical and geochemical methods to detect any signs of activity or changes in their magma chambers.

These methods include measuring seismic waves, ground deformation, gravity, magnetic fields, and gas emissions.

By combining these data with numerical models and simulations, we can estimate the size, shape, location, and pressure of the magma chambers, and how they evolve over time.

A recent study by scientists from Romania, Hungary, France, and Germany focused on the Ciomadul volcano, which is the youngest and largest volcanic complex in the Carpathian-Pannonian region of Eastern Europe.

The study used a combination of geophysical and geochemical techniques to reveal the presence of an active magma chamber under the volcano, which contains about 12 to 15 cubic kilometers of melt.

The study also found that the magma chamber is periodically recharged by fresh magma from the mantle, and that the melt fraction is high enough to allow rapid ascent and eruption.

The study concluded that Ciomadul has the potential to produce explosive eruptions, even after a long period of dormancy.

Researchers also calculated the probability of explosive eruption at Ciomadul, based on the time since the last eruption and the frequency of past eruptions.

The study found that the probability of explosive eruption is not constant, but increases with time. It is estimated that the current probability of explosive eruption at Ciomadul is about 0.004% per year, which means that there is a 1 in 25,000 chance of an eruption in any given year.

However, this probability will increase to 0.01% per year after 40,000 years of dormancy, and to 0.1% per year after 100,000 years of dormancy.

The study also compared Ciomadul with other long dormant volcanoes around the world, such as Yellowstone in the USA, Taupo in New Zealand, and Campi Flegrei in Italy.

According to the study, Ciomadul has a similar or higher probability of explosive eruption than these volcanoes, which are considered among the most dangerous on Earth.

The study suggested that Ciomadul should be monitored more closely and included in the global volcanic hazard assessment.

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