London Daily

Focus on the big picture.

The enigma of Europe's submerged behemoth

The enigma of Europe's submerged behemoth

Off the southern coast of Italy, the largest active volcano in Europe lies hidden beneath the waves. Now scientists are mapping what would happen if it erupted.

When we think of Italy's volcanoes, we may assume that Etna, which overshadows Sicily, and Vesuvius, which famously destroyed Pompei, present the biggest danger to the peninsula's population and tourists. Yet there is another monster that could wreak havoc to the southern peninsula and its islands.

Its name is Marsili, and it is located around 175km (110 miles) south of Naples. With a height of 3,000m (9,800ft), and a base 70km long by 30km wide (43 by 19 miles), Marsili is a true giant. It is the largest active volcano in the whole of Europe. You won't ever see it, however, since its peak is 500m (1,640ft) under water, in the Tyrrhenian Sea.

Scientists have known of Marsili's existence for a century, but it is only within the last decade that they have started to investigate the dangers that Marsili might pose – and their findings are concerning. According to some recent models, its activity could potentially trigger an enormous tsunami, with a 30m-high (98ft) wave hitting Calabrian and Sicilian coasts.

Beneath the waves near the Aeolian islands, volcanic fissures bubble gases that force their way up through the Earth's crust


Worse still, there would be next-to-no warning that the disaster was imminent – a fact that is leading some scientists to call for new technology to monitor the Mediterranean's movements.

An ancient menace


In terms of sheer size, Marsili cannot compete with Tamu Massif, beneath the north-west Pacific Ocean, which is around 4,460m (14,600ft) tall, and may house a complex of several separate volcanoes. Tamu Massif is extinct, however, whereas Marsili continues to rumble. It lies near the boundary of the Eurasian and African tectonic plates – movement that results in heightened geological activity.

In the worst-case scenario, a 20m-high (66ft) wave could crash into Sicily and Calabria within 20 minutes of a landslide


It is just one of many volcanos in an arc off the south coast of Sicily and the east coast of southern Italy. Some of these have formed land masses, the Aeolian islands – Stromboli, Lipari, Salina, Filicudi, Alicudi, Panarea and Vulcano, which was named after the Roman god of fire and which gave us the general name for all such fissures in the Earth's crust. And for every one of these visible islands, 10 volcanoes lurk below the sea.

According to Guido Ventura, a volcanologist at Italy's National Institute of Geophysics and Volcanology, Marsili was born around a million years ago. Over the millennia, it came to amass 80 eruptive cones, spanning from the north-north-east to the south-south-west, alongside many fissures and fractures that could each vent lava.

The Aeolian islands are formed from a string of volcanoes in the Tyrrhenian Sea to the north of Sicily


Thanks to its depth beneath the sea, this potential time-bomb lurking on south Italy's ocean floor was only discovered 100 years ago. "It was only in the early 20th Century that people started to map the sea basins," says Ventura. This was driven, in part, by the military's increasing use of submarines, and the world's new international communication systems, which required telegraph cables to be draped along the seabed. As a result of these efforts, cartographers finally identified the seamount in the 1920s. They named it after the polymath Luigi Ferdinando Marsili (1658-1730), who, among many other achievements, wrote the first treatise on hydrography.

If knowledge of the existence of Marsili was a long time coming, the emergence of scientific research into its activity is even more recent – with detailed studies only appearing in the 2000s. According to these findings, the volcano's last eruption occurred a few thousand years ago. Today, its activity is limited to gentle rumblings, with gaseous emissions and low-energy tremors, Ventura says.

This does not, of course, preclude a more dramatic return to life in the future; Marsili may simply be dozing. If it were to erupt again, the lava and ashes produced by the explosion would be absorbed by the 500m (1,640ft) of water above the seamount; there's little risk that the fiery belch could ever reach the land or harm local populations.

Vulcano was named after the Roman god of fire, which has been adopted to become the generic name for all volcanoes


"The danger isn't the eruption, but the possible underwater landslides," says Ventura. If the seismic movements beforehand, or the explosion itself, led one of its flanks to collapse, it would displace such a large volume of water that it would trigger a tsunami.

The devastation of Naples


We now know that submarine landslides from the Aeolian arc of volcanoes could have contributed to past tragedies.

In 1343, for instance, the poet Petrarch described a terrible sea storm that devastated the Bay of Naples, leading to hundreds of deaths.

A recent study by Sara Levi at the State University of New York and colleagues suggests this may have been the result of a tsunami, originating on Stromboli. Analysing archaeological evidence from the volcano, the team found evidence of an ancient landslip, resulting in a tsunami that reached the Calabrian coast.

A more recent eruption at Stromboli, in 2002, led to two tsunamis in 2002. The waves only affected the island itself, however, without reaching the mainland – and no one was killed by the surge.

A landslide on the slopes of Marsili could cause a 20m-high (66ft) wave travelling towards the coast of the Bay of Naples


Unfortunately, we can't yet calculate the precise threat from Marsili. "We just don't have enough data," says Glauco Gallotti, a physicist at the University of Bologna. But there are good reasons to think it may pose a danger, he says. For one thing, the continuing hydrothermal activity could have weakened the volcano's rocks. What's more, recordings of microearthquakes shows that lava is still churning in the magma chamber, he says. For both these reasons, we should take the possibility seriously with further research.

In a paper published earlier this year, Gallotti's team considered five different scenarios, each examining the effects of different possible landslides. In the first couple of cases, the displacement of water was minimal – leading to a wave of just a few centimetres in height.

A collapse on the north-western flank, however, proved to be more serious – leading to a 3-4m high (10-13ft) wave reaching southern Campania, and a 2-3m high (6.6-10ft) wave hitting Calabria and Sicily within 30 minutes of the event. This is worth taking seriously, since a "scar" on Marsili's seamount suggests that a similar landslide may have occurred in the past. "And it could have generated waves between 1m and 3m high [3-10ft]," says Gallotti.

The worst-case scenario involved the collapse of the southern-central summit and the eastern flank. According to Gallotti's calculations, it would result in a 20m-high (66ft) wave reaching Sicily and Calabria within 20 minutes. Further research will be needed to assess the probability that this will occur, he emphasises. "But we can't [yet] rule out the possibility."

If an eruption does happen, the human cost may depend on the time of year, and whether or not the tsunami arrived in the peak of the tourist season. "The south of Italy is vastly populated in the summer," Gallotti says. The elevation of Italy's coastline means that people should be safe if they were around one kilometre inland, he estimates.

Seismic sisters


Ventura agrees that these risks should be explored. "It's clear that Marsili needs to be monitored for possible instabilities on its flanks."

As the events at Stromboli had shown, Marsili may be the biggest volcano in Europe, but its sisters could also pose significant threats. "It's worth remembering that in the Tyrrhenian Sea, as in the Strait of Sicily, there are at least 70 underwater volcanoes, whose story, in some cases, is totally unknown," says Ventura.

The damage caused by a tsunami caused by a collapse of Marsili would depend on whether it coincided with peak tourist season


Of particular concern is the Palinuro volcano, located 65km (40 miles) off the coast of Cliento. According to Gallotti, recent studies show that the volcanic complex has a 150m-layer (490ft) of loose material that could be displaced with seismic movements. Ideally, future surveys will provide further details of that structure and its chances of collapse.

If the risk is significant, the Italian government may need to take action to pre-empt the potential disaster. At the moment, there is no good monitoring system to warn Italian people of an impending tsunami. But it need not be too difficult to build, Gallotti says. He points out that a network of buoys, fitted with motion sensors, should be able to detect characteristic differences in the sea's movements that signal the emergence of a tsunami. This could send an automatic SMS alert to people in the areas affected – allowing them to reach higher ground before the tsunami hit.

Ventura suggests it may also be possible to monitor the movements of the volcano itself. "In the last 40 years the technology for monitoring active volcanoes has made huge strides," he says.

In addition to an early warning system, Gallotti would also like to see greater awareness of the potential danger – among the public and policy makers. As evidence, he cites a paper by Teresita Gravina, at Guglielmo Marconi University, Nicola Mari at the University of Glasgow, and colleagues, which recently assessed people's risk perception in southern Italy.

In general, people were aware that tsunamis could occur in the area, but their knowledge was hazy. When asked about the most recent events, for example, only 3.3% of the people who answered mentioned the 2002 tsunami at Stromboli, for instance. Most believed themselves to be ill-informed about the events, with limited knowledge of the tsunami's potential causes or the best ways to act, were another to occur.

"This is quite serious," Gravina and Mari told BBC Future in an email. "It's probably due to the fact that in Italy there's little communication on these subjects. To know how a seismic phenomenon, or a tsunami, forms is very important, because you can assess completely different scenarios and the different behaviours that would be necessary to avoid the danger." Any attempts to design an effective early warning system would need to consider the behaviours of the different communities, they say. (We've already seen this with Covid-19 – two populations can react to exactly same information in very different ways.)

There have been some positive steps. A recent project in Salerno, organised by Italy's Civil Protection Department, attempted to simulate the emergency caused by a tsunami. "This could have increased their awareness of the risk," Gravina and Mari say. But for most people, the danger of an underwater landslide, caused by a submarine volcano, is still little understood – meaning that much more work is needed to educate people of the possibility.

The danger of a tsunami may seem remote – but should it come to pass, a little knowledge could help save thousands of lives.

Newsletter

Related Articles

London Daily
0:00
0:00
Close
Unelected PM of the UK holds an emergency meeting because a candidate got voted in… which he says is a threat to democracy…
You Are So Beautiful
Rob Schneider explains California reparations legislation.
Postmodern Jukebox European Tour Version
Who knew badminton could get so intense?
An old French tune (by Georges Brassens) Pomplamoose ft. John Schroeder
Farmers break through police barriers in Brussels.
Sattahip Motor Show 20
London's Iconic British Telecom Tower Sold To Become Hotel
SONATE AU CLAIR DE LUNE - Moonlight sonata
Ukraine Arrests Father-Son Duo In Lockbit Cybercrime Bust
A kiss to build a dream on
US Offers $15 Million For Info On Leaders Of Cybercrime Group Lockbit
Wonderful Tonight - Eric Clapton (Boyce Avenue acoustic cover)
Russia Claims UK Cultural Agency Spied for Ukraine
Mean Blues
Apple warns against drying iPhones with rice
La Chansonnette
Alexei Navalny: UK sanctions Russian prison chiefs after activist's death
Pattaya Addicts
German economy is in 'troubled waters' - ministry
Franz Liszt - Liebestraum - Love Dream
In a recent High Court hearing, the U.S. argued that Julian Assange endangered lives by releasing classified information.
Dream a little dream of me
New video
Unchained Melody sung like you've NEVER heard!
Tucker Carlson says Boris Johnson wants "a million dollars, in Bitcoin or cash, from Tucker Carlson to talk about Ukraine.
Dave Brubeck - Take Five
Russia is rebuilding capacity to destabilize European countries, new UK report warns
Édith Piaf - Non, Je Ne Regrette Rien (Sofie)
EU Commission wants anti-drone defenses at Brussels HQ
Rondo Alla Turca
Von der Leyen’s 2nd-term pitch: More military might, less climate talk
Kiss of fire
Global Law Enforcement Dismantles Lockbit Ransomware Operation
Tom Jones - I´ll Never Fall In Love Again 1967, 1989, 2001
Prince William Urges End to Gaza Conflict
Israel Cachao López - Guajira Clásica
UK court to hear Assange's final appeal against extradition to the US, where he faces charges related to his journalistic work—the publication of a classified video in 2010 that exposed US war crimes against humanity.
Edward Maya - Stereo Love (feat. Vika Jigulina) (Extended Mix)
About 50-60% kids either chose to be YouTuber or influencer
Strauss - Radetzky March - Karajan
A viral video of Nationals MP Barnaby Joyce lying on a Canberra footpath is celebrated by his media mates.
La vie en rose
European Countries React to Navalny's Death by Summoning Russian Diplomats
The Temptations - My Girl (Smokey Robinson Tribute) 2006 Kennedy Cent
Israel has gone ‘beyond self-defence’ in Gaza, says Labour’s Streeting
Orlando Cachaito Lopez Redencion
English farmers to be offered ‘largest ever’ grant scheme amid food security concerns
Edith Piaf - NON, JE NE REGRETTE RIEN
Cameron government knew Post Office ditched Horizon IT investigation
RADETZKY MARCH-2008-Wien, New Year Concert
EU Calls for Immediate Ceasefire in Gaza Conflict
Only you (And you alone)
EU Vows To Hold Putin "Accountable" After Meeting Alexei Navalny's Wife
Strangers In The Night
EU Launches Probe Into TikTok Over Child Protection Under Digital Content Law
Charles Aznavour - La Boheme
The EU Initiates Naval Mission to Defend Red Sea Trade Routes
Summer time
EU and UK Announce Joint Effort on Migration
Sting and Stevie Wonder - Fragile (from Sting's 60th birthday concert)
Brazil's Lula Likens Gaza Operation to Holocaust, Israel Says "Red Line" Crossed
Aux Champs Elysees
Ministers Confirm Proposal to Prohibit Mobile Phone Usage in English Schools
Stand By Me - Ben E. King (Boyce Avenue acoustic cover)
Microsoft-backed OpenAI valued at $80bn after company completes deal
La Mer (Beyond the Sea) – Avalon Jazz Band
‘Alexei would want to tell Russia not to give up fighting’
She
Rwandan Footballer's Dismissal Sparks Concerns Over UK Asylum Plan
Nathalie Song by Enzo Petrachi Stjepan Hauser Cello
Whisky Challenges China's Baijiu Market During New Year Celebrations
Shape of My Heart - Sting (Boyce Avenue acoustic cover)
Avdiivka - Symbol Of Ukrainian Resistance Now In Control Of Russian Troops
Radiohead - Creep
Putin Critic Alexei Navalny's "Killers" Refusing To Hand Over Body, Say Allies
Quizás,Quizás,Quizás - Andrea Bocelli - Jennifer Lopez
"Historic Step": Zelensky Signs Security Pact With Germany
Perhaps, Perhaps, Perhaps - Multi-Couples
"Historic Step": Zelensky Signs Security Pact With Germany
Pentatonix Havana
20 Tech Giants Sign Effort To Fight AI Election Interference Across Globe
Paula Cole - Autumn Leaves
Joe Biden Accuses Putin of Causing Navalny's Death
Oscar Benton Bensonhurst Blues
Russian opposition leader Alexey Navalny has died at the Arctic prison colony
OH NANANA vs ABUSADAMENTE
Tucker Carlson grocery shopping in Russia. This is so interesting.
Nina Simone - ”I Put A Spell On You”. Vezi aici cum cântă Jeremy Ragsd
Julian Assange's Wife Warns of His Death if Extradited to US
NIGHTWISH - The Phantom Of The Opera
‘A lot higher than we expected’: Russian arms production worries Europe’s war planners
Motorshow 2016 Tanjay Negros Oriental
Greece Legalizes Same-Sex Marriage and Adoption Rights
Monica Bellucci - Ti Amo
Hungarian Foreign Minister: Europeans will lose Europe, the Union's policy must change drastically
Michael Jackson - Billie Jean Milena The Voice France 2018
In Britain Homeowners are receiving CPO’s (Compulsory Purchase Orders) so their homes can be redistributed to migrants
Michael Buble (Help Me Make It Through The Night) feat Loren Allred
Memories Canon In D - Maroon 5 (Boyce Avenue piano acoustic cover)
Matteo Simoni - Marina
Maroon 5 - One More Night
Maroon 5 - Memories
Mark Knopfler - Brothers In Arms (Berlin 2007 Live)
Mark Knopfler & Emmylou Harris - Romeo And Juliet (Real Live Roadrunni
Marina, Marina - The LUCKY DUCKIES intimist live concert at Guimarães
Major Lazer & DJ Snake – Lean On Mauranne The Voice France 2016
Love Theme from Romeo and Juliet - Joslin - Henri Mancini, Nino Rota
LoLa & Hauser - Love Story
Linkin Park Jay-Z - Numb Encore (Live 8 2005)
Hallelujah Mennel Ibtissem, The Voice France Leonard Cohen
Leonard Cohen - Dance Me to the End of Love
Leonard Cohen & Natasha Rostova - Dance me to the end of love
La casa de papel - Bella Ciao
La Camisa Negra
L'italiano (Toto Cutugno) - The Gypsy Queens
Juanes - La Camisa Negra
Jonathan and Charlotte - Britain's Got Talent 2012 Live Semi Final - U
John Powell - Assassin's Tango
Joe Cocker - You Can Leave Your Hat On (LIVE in Dortmund)
Joe Cocker - Unchain My Heart 2002 Live
Joe Cocker - A Whiter Shade Of Pale
Jay Z & Alicia Keys - Empire State of Mind LIVE
Jason Mraz - Im Yours (live)
Jarrod Radnich - Bohemian Rhapsody - Virtuosic Piano Solo
James Blunt - You're Beautiful
James Blunt - You're Beautiful & Bonfire Heart (Live at The Nobel Peac)
If You Go Away - Helen Merrill & Stan Getz (Tribute to Virna Lisi)
I'LL BE MISSING YOU
I Say a Little Prayer
Hotel California ( Eagles ) 1994 Live
Historia de un amor - Luz Casal. Vezi interpretarea Biancăi Sumanariu
Here Comes The Sun - The Beatles (Boyce Avenue acoustic cover) on Spot
Heart - Stairway to Heaven Led Zeppelin - Kennedy Center Honors
HAVANA by Camila Cabello Zumba Pre Cooldown TML Crew Kramer Pastra
HAUSER and Señorita - I Will Always Love You
HAUSER - Waka Waka
HAUSER - Sway
HAUSER - Lambada
HAUSER - Historia de un Amor
HAUSER - Despacito
Great Pretender
Georgia May Foote & Giovanni Pernice Samba to 'Volare' - Strictly Come
Gary Moore - Still Got The Blues
GIPSY KINGS VOLARE Penelope Cruz
Fugees - Killing Me Softly With His Song
French Latino - Historia de un Amor
For A Few Dollars More The Danish National Symphony Orchestra (Live)
Flashdance • What a Feeling • Irene Cara
Filip Rudan - “Someone You Loved” Audicija 4 The Voice Hrvatska Sez
Eric Clapton - Wonderful Tonight
Enya - Only Time
Enrique Iglesias - Bailando (English Version) ft. Sean Paul
Enrique Iglesias - Bailamos
Elena Yerevan Historia de un amor
Ed Sheeran - Shape of You (Official Music Video)
Ed Sheeran - Perfect Symphony [with Andrea Bocelli]
Ed Sheeran - Perfect (Official Music Video)
Easy On Me - Adele (Boyce Avenue 90’s style piano acoustic cover) on S
ERA - Ameno
ELENA YEREVAN- Cancion Del Mariachi-IN STUDIO-2017 DPR
Dust In The Wind - Kansas (Boyce Avenue acoustic cover)
Don't Let Me Be Misunderstood
Despacito x Shape Of You - Pentatonix
Deep Purple - Child In Time - Live (1970)
David Foster When A Man Loves A WomanIt's A Mans World (SealMichael Bo
Dance me to the end of Love ( Pi-Air Design )
Coolio - Gangsta's Paradise (feat. L.V.) [Official Music Video]
Conquest Of Paradise (Vangelis), played on Böhm Emporio organ
Cielito Lindo
Chico & The Gypsies - Bamboleo
Canción Del Mariachi - Antonio Banderas, Los Lobos • Desperado
Camila Cabello - Havana (Audio) ft. Young Thug
Camila Cabello - Havana ( cover by J.Fla )
California Dreamin' - The Mamas & The Papas José Feliciano (Boyce Ave
Buster Benton - Money Is The Name of The Game
Hallelujah Pentatonix
Bobby McFerrin - Don't Worry Be Happy (Official Music Video)
Bob Dylan - Knockin' On Heaven's Door Emilia The Voice Kids France
Besame Mucho - Cesaria Evora
Ben E. King - Stand by Me Sax Cover Alexandra Ilieva Thomann
Bella Ciao
Bella Ciao - INSTRUMENTAL
Beautiful in White x Canon in D (Piano Cover by Riyandi Kusuma)
Bad Romance - Vintage 1920's Gatsby Style Lady Gaga Cover ft. Ariana Savalas & Sarah Reich(1)
BELLA CIAO 2020 - KARAOKE ITALIANO
BAMBOLEO - Gipsy Kings • Antonio Banderas, Katya Virshilas
BAILANDO (original)
Awesome Ukrainian yodeler - SOFIA SHKIDCHENKO (with English subtitles)
Avicii - The Nights
Atom - The Great Gig in the Sky
Aretha Franklin - (You Make Me Feel Like) A Natural Woman (Official Ly
Antonio Banderas - Cancion del Mariachi (Desperado)
André Rieu - Zorba's Dance (Sirtaki)
André Rieu - Can't Help Falling In Love
André Rieu & Mirusia - Ave Maria
Andrew Reyes Elton John - Don't Let The Sun Go Down The Voice 2020 (
Andreas Kümmert Whiter Shade Of Pale The Voice of Germany 2013 Showd
And I Love You So
All About That Bass - Postmodern Jukebox European Tour Version
Alan Walker - Faded (Piano Cover)
Ain't No Sunshine -- Bill Withers (cover by Canen 12 y.o.)
African music
Adriana Vidović - “Creep” Audicija 4 The Voice Hrvatska Sezona 3
Adriana Vidović - “Believer” Nokaut 3 The Voice Hrvatska Sezona 3
A Fistful of Dollars - The Danish National Symphony Orchestra and Tuva
4 Beautiful Soundtracks Relaxing Piano [10min]
2CELLOS - Whole Lotta Love vs. Beethoven 5th Symphony [OFFICIAL VIDEO]
2CELLOS - Smooth Criminal (Live at Suntory Hall, Tokyo)
2CELLOS - Smells Like Teen Spirit [Live at Sydney Opera House]
2CELLOS - Despacito [OFFICIAL VIDEO]
13 Year Old Girl Playing Il Silenzio (The Silence) - André Rieu
094.All About That Bass
00 - SADNESS PART 1
(Ghost) Riders In the Sky (American Outlaws Live at Nassau Coliseum, 1
(Everything I Do) I Do It For You - Bryan Adams (Boyce Avenue ft. Conn
What a wonderful world
Moon river
×