Did highest known sea levels create the iconic shape of Mount Etna?

March 30, 2018 by Mr Alan Williams, University of Plymouth
Credit: CC0 Public Domain

The iconic cone-like structure of Mount Etna could have been created after water levels in the Mediterranean Sea rose following an extended period of deglaciation, according to new research.

A study by Iain Stewart, Professor of Geoscience Communication at the University of Plymouth, explores changes in the volcano's structures which began around 130,000 years ago.

Scientists have previously said the switch from a fissure-type shield volcano to an inland cluster of nested stratovolcanoes was caused by a tectonically driven rearrangement of major border faults.

However Professor Stewart, writing in Episodes, has suggested the change coincides closely with a period of particularly high sea levels that could have triggered the fundamental change in Mount Etna's magmatic behaviour.

He also believes such a phenomenon could also explain changes at other volcanic sites across the world including the similarly iconic Stromboli, just off the north coast of Sicily, and even the volcano on Montserrat in the Caribbean.

Professor Stewart, who fronted the BBC documentary Volcano Live in 2013, said: "Mount Etna is arguably one of the most iconic volcanoes on the planet, but 100,000 years ago there would have been no cone-like structure such as you see today. I had always been interested to know what prompted that to happen but I believe the dates of sea levels rising—and how they correspond to the volcano physically changing - offer a potential explanation. The precise sensitivities of the plumbing beneath Etna has always been something of a mystery, but exploring how sea levels interact with its fault lines could shed new light on its creation and future."

Mount Etna's eruptive history began around 500,000 years ago with submarine volcanism. But this changed around 220,000 years ago into fissure type activity which built a north-south chain of eruptive centres along the present coastline.

This ultimately created a broad shield volcano immediately east of Etna's coastline, which ceased around 130,000 years ago at the same time as the sea reached its highest levels following a period of deglaciation starting almost 12,000 years earlier.

However, Professor Stewart believes that over a few millennia those rises could have caused the fault system beneath and around Mount Etna to completely change in behaviour, sealing up old lava flows and ultimately forcing them to emerge elsewhere on the island.

This ultimately created the iconic cone structure visible today, with Europe's most active volcano still continuing to erupt tens of thousands of years later.

This new research has been published days after another study showed that Etna is edging towards the Mediterranean at a rate of around 14mm per year.

Professor Stewart added: "The latest measurements of Etna's seaward slide give us a much better understanding of just how unstable Europe's biggest is. But the big question remains: what is driving that instability? For me, the fact that Etna's dramatic switches in eruptive behaviour coincide with past abrupt changes in ocean levels implies that Etna's antics are at least in part orchestrated by fluctuating waters of the Mediterranean Sea."

Explore further: Volcanologist suggests Mt. Etna behaves more like a giant hot spring than a volcano

More information: Did sea-level change cause the switch from fissure-type to central- type volcanism at Mount Etna, Sicily?, Episodes (2018). DOI: 10.18814/epiiugs/2018/v41i1/018002

Related Stories

Mt. Etna found to be sliding downhill towards the sea

March 26, 2018

A small team of researchers from the U.K and France has found evidence indicating that Sicily's Mt. Etna is sliding very slowly downhill toward the sea. In their paper published in Bulletin of Volcanology, the group describes ...

Image: Etna erupts

March 17, 2017

This image of the lava flowing from Mount Etna in Sicily, Italy, was captured today at 10:45 GMT (11:45 CET) by the Copernicus Sentinel-2A satellite.

Recommended for you

In colliding galaxies, a pipsqueak shines bright

February 20, 2019

In the nearby Whirlpool galaxy and its companion galaxy, M51b, two supermassive black holes heat up and devour surrounding material. These two monsters should be the most luminous X-ray sources in sight, but a new study using ...

Research reveals why the zebra got its stripes

February 20, 2019

Why do zebras have stripes? A study published in PLOS ONE today takes us another step closer to answering this puzzling question and to understanding how stripes actually work.

When does one of the central ideas in economics work?

February 20, 2019

The concept of equilibrium is one of the most central ideas in economics. It is one of the core assumptions in the vast majority of economic models, including models used by policymakers on issues ranging from monetary policy ...

Correlated nucleons may solve 35-year-old mystery

February 20, 2019

A careful re-analysis of data taken at the Department of Energy's Thomas Jefferson National Accelerator Facility has revealed a possible link between correlated protons and neutrons in the nucleus and a 35-year-old mystery. ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.