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Earth of fire

Actualité volcanique, Articles de fond sur étude de volcan, tectonique, récits et photos de voyage

Articles avec #historical eruptions catégorie

Publié le par Bernard Duyck
Publié dans : #Excursions and trips, #Historical eruptions

The scenery planted, let's move on to the history of the volcanic field of Santorini, which consists of 6 different stages.

- Akrotiri Volcanoes (about 2 Ma - 600,000 years old)
- Ash cones of the Akrotiri peninsula (about 600 - 300 ka)
- Peristeria Volcano (530 - 300 ka)
- Products of the first eruptive cycle (360-172 ka)
- Products of the second eruptive cycle (172 ka - 1613 BC)
- Shield Kameni (1613 BC)

 

The volcanism in the Santorini region began about 2 million years ago, when the first eruptions occurred on the seabed in the region of the Akrotiri Peninsula and probably also at the location of the islands Christiania, 20 km southwest of Santorini.
The activity led to the construction of dacitic lava domes that eventually formed a series of islands, still visible in the hills of the Akrotiri Peninsula.

 In a second time, a stratovolcano (Peristeria volcano) formed in the northern part of Santorini, some parts of which are still visible in the cliffs and slopes of Mikro Profitis Ilias and Megalo Vouno.

From 400,000 years ago, volcanic activity moved to the center of the current caldera. The most characteristic type of activity over the past 400,000 years has been the cyclical construction of volcanoes-shields interrupted by major explosive and destructive events such as the Minoan eruption of about 3,600 years ago.

(Full text and details: see Druitt & al., 1999 - references in sources)

The volcanic complex of Santorini - Doc. The morphodynamic evolution of Santorini volcanic complex - Doc. Nomikou, Vouvalidis, Pavlides 2019

The volcanic complex of Santorini - Doc. The morphodynamic evolution of Santorini volcanic complex - Doc. Nomikou, Vouvalidis, Pavlides 2019

Eruptive history of Santorini - Doc. Thamsin Mather

Eruptive history of Santorini - Doc. Thamsin Mather

Santorini - Thêra - the lavas of Cap Skaros, under Imerovigli - photo © Bernard Duyck 09.2019

Santorini - Thêra - the lavas of Cap Skaros, under Imerovigli - photo © Bernard Duyck 09.2019

 Santorini - Therasia - detail of the cliffs - photo © Bernard Duyck 09.2019

Santorini - Therasia - detail of the cliffs - photo © Bernard Duyck 09.2019

The volcanic evolution of Santorini is marked by at least 4 episodes of caldera collapses that have taken place for 172,000 years, during 2 eruptive cycles, each cycle beginning with a mafic to intermediate volcanism and ending with silicic extrusions accompanied by collapse events. The remains of these are observed on the cliffs of the caldera, usually defined by unconformities and layers of underlying paleosols.

 

Caldeira 1 - 172,000 years: located south of Thêra, and defined by a discrepancy of 150 m. covered by pyroclastic deposits.

Caldeira 2 - 76,000 years old: located north of Thêra and formed by eruptive Middle tuff series, covered by lava of Skaros (67,000 years)

Caldeira 3 - 22,000 years old: located in the caldera wall north of Thêra and in the port of Fira (Minoan pumice layer of 140 m.)

Caldeira 4 - 3,600 years: located north of the Kameni line.

At the port of Athinios, we notice the collapse of the Minoan eruption (tuff) which exhumed the northwestern cliff and the shore of the pre-volcanic bedrock.

Santorini - Thêra - Cap Skaros lava - photo © Bernard Duyck 09.2019

Santorini - Thêra - Cap Skaros lava - photo © Bernard Duyck 09.2019

Santorini - Thêra - cliffs with pre-volcanic lithological basement at the port of Athinios - photo © Bernard Duyck 09.2019

Santorini - Thêra - cliffs with pre-volcanic lithological basement at the port of Athinios - photo © Bernard Duyck 09.2019

The geomorphology is revealed by an underwater topographic and bathymetric map, published by Evi Nomikou.

The walls of the caldera rise up to 300 meters above sea level, while the maximum depth of the caldera floor is about 390 meters below the water level.

Caldera de Santorini - bathymetric and topographic combined map - Doc. Nomikou & al. 2014

Caldera de Santorini - bathymetric and topographic combined map - Doc. Nomikou & al. 2014

The caldera consists of three distinct basins forming separate depositional environments.

The northern basin is the largest and deepest, between the Kameni Islands, Thirasia and the northern part of the caldera. It is connected by a narrow channel, with steep walls 300 meters deep, to an ENE-WSW structure in form of shell that lies outside the Santorini caldera, northwest of the village of Oia.

The smaller western basin, between the Islet of Apronisi, Palea Kameni and the south of Thirasia, has a depth of up to 325 meters.

The southern basin, bordered by the Kameni Islands and the southern part of the caldera, is shallower than the west basin of about 28 meters.

The morphology of the sea floor suggests that the southern basin is separated from the others by the development of a series of subaerial and submarine volcanic domes, aligned NE-SW.

 

This unique morphology plays an important role in the occurrence of rock slides and a risk of landslide over a very large area, with major risks for the internal caldera cliffs north of Thera and east of Thirasia.

 

Sources:

- The morphodynamic evolution of Santorini volcano complex - 09,2019 - Paraskevi Nomikou (National and Kapodistrian University of Athens), Konstantinos Vouvalidis and Spyros Pavlides (Aristotle University of Thessaloniki)


- Geological Society memoir n ° 19 - Santorini volcano - T.H.Druitt (Laboratory Magmas and Volcanoes (UMR6524 and CNRS), Blaise Pascal University, 5, Rue Kessler, 63038 Clermont Ferrand, France) & al.1999

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Publié le par Bernard Duyck
Publié dans : #Excursions et voyages, #Historical eruptions
 The track along the reservoir Azat-Zabasen and Grand Ararat - photo © Bernard Duyck 2019

The track along the reservoir Azat-Zabasen and Grand Ararat - photo © Bernard Duyck 2019

Theoretically easily accessible from our base in northern Yerevan, the Khor Virap Monastery and its famous view of the two peaks of Ararat, were made for us very difficult because of a landslide.

We then passed by Garni, and a track, doubled by a pass, skirting the reservoir of Azat-Zabasen ... course a little more rugged, but spectacular in a semi-desertic region where we did not meet as some shepherds and their sheep.

The Great Ararat and the Lesser Ararat in a pastoral landscape - photo © Bernard Duyck 2019
The Great Ararat and the Lesser Ararat in a pastoral landscape - photo © Bernard Duyck 2019

The Great Ararat and the Lesser Ararat in a pastoral landscape - photo © Bernard Duyck 2019

The summit of the Great Ararat in a heat haze - photo © Bernard Duyck 2019

The summit of the Great Ararat in a heat haze - photo © Bernard Duyck 2019

Khor Virap - stele of St. Gregory - photo © Bernard Duyck 2019

The monastery of Khor Virap is built on a hill of Artachat, former capital of Armenia. The origins of the monastic complex, attached to the Armenian Apostolic Church, go back to the seventh century: it was built on the spot where Saint Gregory the Illuminator, patron saint of the country, was imprisoned for thirteen years. In this place, Biblical history mingles intimately with that of the Christians of Armenia and the Armenian nation.

 

The monastery of Khor Virap and Grand Ararat - photo © Bernard Duyck 2019

The monastery of Khor Virap and Grand Ararat - photo © Bernard Duyck 2019

The monastery of Khor Virap - photo © Bernard Duyck 2019

The monastery of Khor Virap - photo © Bernard Duyck 2019

Mount Ararat is venerated by Armenians. Although the latter were the first to adopt Christianity as a national religion, in 301, Mount Ararat remains for them the home of Ara, supreme deity of their pre-Christian pantheon. Formerly, the mountain was included in the borders of "the Great Armenia".

In 1921, the area was incorporated into Turkey and the peaks now rise 32 kilometers from the border. Always visible from Yerevan, the Armenian capital, but inaccessible, Mount Ararat became, for the Armenians, the symbol of the tragic fate of their nation, victim, between 1915 and 1923, of deportations and massacres perpetrated by Ottoman Turkey. Access to the sacred volcano remained banned until 1990 for strategic reasons, with the Republic of Armenia under Soviet domination. The Armenians are more attached to it : Ararat is on the national coat of arms, on bank notes and stamps, and it is in the spotlight in paintings, poems and songs.

The first stamps issued after Independence, with Ararat (1992)

The first stamps issued after Independence, with Ararat (1992)

Mount Ararat is a polygenic stratovolcano covering 1,100 km² and consisting of two distinct volcanic cones, the Great Ararat, 5,165 meters and the Lesser Ararat, 3,896 meters, connected by a lava plateau. Its measurements - 45 km on 30 km. - make it the largest volcanoes aligned on an SSO-ESE axis from the Nemrut Dagi.

Ararat seen from the space shuttle in 2001 - Great Ararat, center - Lesser Ararat, right - photo Earth Sciences and Image Analysis Laboratory, NASA Johnson Space Center, 2001 in GVP

Ararat seen from the space shuttle in 2001 - Great Ararat, center - Lesser Ararat, right - photo Earth Sciences and Image Analysis Laboratory, NASA Johnson Space Center, 2001 in GVP

Of recent formation, between the tertiary and the quaternary, in an infrequent context of volcanism of the zones of collision, the Ararat mountains result from the accumulation of lava flows and successive pyroclastic ejections.

After a period of production of andesitic tuffs, encountered in the clear base of the volcano, there was an influx of basalt and andesite flows, forming the darker lower slopes up to 3,000 m. altitude. The summit of Great  Ararat is formed by two trachytic domes separated by a string of 400 meters long.

The establishment of the Ararat Mountains was followed by a period characterized by eruptions of flanks, following N-S oriented cracks. The initial phase produced cinder cones and rhyolitic dacitic lava domes around the Great Ararat and a series of pyroclastic cones and domes on the western flank of Lesser Ararat. The final stage is responsible for the formation of pyroclastic cones on the lower flanks of the two volcanoes.

Ararat seems to have been active during the 3rd millennium BC; Pyroclastic deposits cover artifacts and human remains from the beginning of the Bronze Age. Karakhanian et al. (2002) reported historical evidence of a phreatic eruption and pyroclastic flow during an earthquake and landslide in July 1840.

 

The ancient history of Ararat is linked to that of the flood around 5,000 BC, due to the breaking of the Bosphorus threshold due to the melting of glaciers, and taken up by various ancient sources: the legend of Gilgamesh, Greek mythology and the Bible (Noah's Ark would have landed there after the flood)

 

To follow: Yerevan, the pink city in volcanic tuff.

 

Sources:

- Global Volcanism Program - Ararat

- The most unrecognized volcanism, the volcanism of collision zones, and its most emblematic active volcano: Mount Ararat (Eastern Turkey) - Planet Earth / Pierre Thomas - link

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Publié le par Bernard Duyck
Publié dans : #Excursions et voyages, #Historical eruptions
The stratovolcano Aragats - two summits - photo © Bernard Duyck 2019

The stratovolcano Aragats - two summits - photo © Bernard Duyck 2019

The Aragats is an andesito-dacitic stratovolcano, 40 km in diameter basal, surmounted by a crater partially collapsed (2.000 x 1.500 m on 400 m of depth) and has four peaks, respectively high of 4.095 m. to the north, 4.080 m. to the west, 3.916 m. to the east and 3,879 m. South.

The stratovolcan Aragats - other summits - photo © Bernard Duyck 2019
The stratovolcan Aragats - other summits - photo © Bernard Duyck 2019

The stratovolcan Aragats - other summits - photo © Bernard Duyck 2019

His formation was done in four stages:

- The first is an andesito-basaltic phase, dated about 2.5 Ma and concerns the main crater and secondary vents.

- The second phase, from 0.97 to 0.89 Ma, and the most important one, is basaltic and andesitic, with ignimbrites emission, production of tuffs and lava flows from satellite centers, including the Shamiran and Egvard centers. .

- The third phase is similar to the second, dated between 0.74 and 0.68 Ma, but only affected the Mantash River basin in the north.

- The fourth, from 0.56 to 0.45 Ma, involves mafic flows from parasite vents south of the volcano.

("Quaternary geochronology of the Aragats volcanic center, Armenia - Evidence from K-Ar dating" I.V.Chernyshev & al.)

Quaternary eruptions from an intraplate multilevel magma reservoir of the Aragats stratovolcano formed pyroclastic density currents and deposition, deposited in an area of ​​approximately 2,000 km², including six ignimbrite units and three fallout deposits.

Aragats and its vast deposits of ignimbrites - Doc. Hripsime Gevorgyan & al.

Aragats and its vast deposits of ignimbrites - Doc. Hripsime Gevorgyan & al.

The stratovolcano Aragats - photo © Bernard Duyck 2019

The stratovolcano Aragats - photo © Bernard Duyck 2019

Located on a steppe plateau north-west of the volcano, the village of Artik owed its development to the vast tuff quarries, and the extraction since medieval times of building materials of Armenian buildings.

Armenia - Aragats volcano - Artik tuff quarries - photo © Bernard Duyck 2019

Armenia - Aragats volcano - Artik tuff quarries - photo © Bernard Duyck 2019

Armenia - Aragats Volcano - Artik tuff quarries: "red" tuff - photo © Bernard Duyck 2019
Armenia - Aragats Volcano - Artik tuff quarries: "red" tuff - photo © Bernard Duyck 2019

Armenia - Aragats Volcano - Artik tuff quarries: "red" tuff - photo © Bernard Duyck 2019

Armenia - Aragats Volcano - Artik tuff quarries: "black" tuff - photo © Bernard Duyck 2019

Armenia - Aragats Volcano - Artik tuff quarries: "black" tuff - photo © Bernard Duyck 2019

On the slopes of the Aragats, the Haritch Monastery (Haritchavank) was built by the Zakarid princes from the 13th century.

Victim of the general decline of the monasteries from the XV-XVI century, it was almost abandoned before being reborn in the middle of the XIX century. It then becomes the summer residence of the Catholicos of Edjmiatzin.

Haritchavank, the Haritch monastery, with its churches :  Sourp Astvatsatsin, Sourp Grigor and the gavit - photo © Bernard Duyck 2019

Haritchavank, the Haritch monastery, with its churches :  Sourp Astvatsatsin, Sourp Grigor and the gavit - photo © Bernard Duyck 2019

Haritchavank stands on the edge of a ravine, prized by the monks, with fish farming - photo © Bernard Duyck 2019

Haritchavank stands on the edge of a ravine, prized by the monks, with fish farming - photo © Bernard Duyck 2019

Other tuff quarries exist southeast of the volcano, still in operation.

Aragats - tuff quarry southeast of the volcano - photo © Bernard Duyck 2019

Aragats - tuff quarry southeast of the volcano - photo © Bernard Duyck 2019

Sources:

- Quaternary geochronology of the Aragats volcanic center, Armenia - Evidence from K-Ar dating - I.V.Chernyshev & al

- Decoding a post-collisional multistage magma system: the quaternary ignimbrites of stratovolcano aragats - Western Armenia - Hripsime Gevorgyan & al.

- Ignimbrites of Armenia - Paleomagnetic constraints on flow and stratigraphy of pyroclastic activity of Mount Aragats

- Aragats stratovolcano in Armenia - Khachatur Meliksetian, deputy director for science, head of Laboratory of volcanology.

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Publié le par Bernard Duyck
Publié dans : #Excursions et voyages, #Historical eruptions
Arménie - obsidienne de la carrière de Jraber / source du verre volcanique : volcan Gutansar - photo © Bernard Duyck 2019

Arménie - obsidienne de la carrière de Jraber / source du verre volcanique : volcan Gutansar - photo © Bernard Duyck 2019

De nombreuses fouilles ont été faite dans le Caucase et l'Anatolie orientale, et nombre d'artefacts retrouvés sur des sites préhistoriques.

Les analyses des archéologues en concluent que l'abondance de l'obsidienne sur un site n'est pas directement liée à la présence d'affleurements au voisinage ... ce qui permet d'identifier les réseaux de commerce, d'échanges au cours de la préhistoire.

Carte de répartition des sources d’obsidienne dans le Caucase et le nord-est de la Turquie et localisation des sites étudiés. - Doc. Ch. Chataigner / références en sources

Carte de répartition des sources d’obsidienne dans le Caucase et le nord-est de la Turquie et localisation des sites étudiés. - Doc. Ch. Chataigner / références en sources

L'obsidienne est un bon marqueur des échanges, parce qu'il est rapidement possible aujourd'hui de lier avec précision un artefact à sa source au moyen d'une caractérisation des élements par la technologie XRF portable / fluorescence par rayons X appareils portables. Les délais de mesures par cette méthode, non destructrice, se sont réduites sur le terrain de 6 minutes à une dizaine de secondes ... ce qui permet de contrôler de nombreux échantillons en temps réel.

Design d'un analyseur portable XRF et ses fonctions basiques. Il est réliable à un ordi et à des prises de données wi-fi .  Image: Thermo Fisher Scientific / Tewksbury-USA 

Design d'un analyseur portable XRF et ses fonctions basiques. Il est réliable à un ordi et à des prises de données wi-fi . Image: Thermo Fisher Scientific / Tewksbury-USA 

Une étude de Ch.Chataigner sur trois sites de fouilles dans la plaine de l'Ararat, situés dans le même environnement, contemporains de la première moitié du 6° millénaire avant notre ère, et appartenant tous à la culture d'Aratashen, renseigne des approvisionnements en obsidienne différents.

Ces trois sites sont à distance-temps quasi égale de Gutansar (évoqué dans l'article d'hier), mais cette source est exploitée de façon préférentielle sur un seul site. Ce fait est à mettre en relation avec les voies de circulation au néolithique. (Chataigner C. 2015. L’approvisionnement en obsidienne dans le Caucase : des questions et des hypothèses, ArchéOrient – Le Blog (Hypotheses.org), 27 mars 2015.)

D'autres études viennent corroborer celle évoquée et permettent de déchiffrer, par archéométrie de l'obsidienne, la circulation des matières premières dans la région.

Arménie - Nucleus en obsidienne d’Aknashen-Khatunarkh - Doc. Ch. Chataigner / références en sources

Arménie - Nucleus en obsidienne d’Aknashen-Khatunarkh - Doc. Ch. Chataigner / références en sources

Sources et études complètes :

- Archéorient - Obsidian supply in the Caucasus: questions and hypotheses - par Christine Chataigner (mars 2005) - link

- An international research project on Armenian archaeological sites: fission-track dating of obsidians - Badalian, R; Bigazzi, G; Cauvin, M.-C; Chataigner, C; Jrbashyan, R; Karapetyan, S.G .; Oddone, M; Poidevin, J.-L (2001)

- Sourcing geochemically identical obsidian: multiscalar magnetic variations in the volcanic Gutansar complex and implications for Palaeolithic research in Armenia. Journal of Archaeological Science.

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Publié le par Bernard Duyck
Publié dans : #Historical eruptions

At the beginning of March, commemorative celebrations begin in Belpasso; they open on the occasion of the 350th anniversary of the eruption of Etna from 16 March to 11 July 1669 which destroyed the old town of Malpasso, the original site of the inhabitants of the current Belpasso.

Malpasso 1669 - Belpasso 2019 - Celebrations of the 350th anniversary of the eruption of Etna - Doc. etnalife / Twitter, featuring a reproduction of a fresco in Catania Cathedral illustrating this eruption - one click to enlarge

Malpasso 1669 - Belpasso 2019 - Celebrations of the 350th anniversary of the eruption of Etna - Doc. etnalife / Twitter, featuring a reproduction of a fresco in Catania Cathedral illustrating this eruption - one click to enlarge

This eruption is special and famous for more than one reason:

- flows were extremely high during this four-month event,

- the main vents are located on the flank of the volcano at an altitude of 800 to 850 m only,

- it generated the longest flow of Etna: 17 km.

- it has been the subject of a large number of detailed and detailed contemporary descriptions,

- it is the most recent eruption that has affected Catania,

- it is also one of the first documented cases of diversion testing of a lava flow.

Old engraving illustrating the eruption of Etna in 1669 - Doc. www.italysvolcanoes.com - The cradle of volcanology

Old engraving illustrating the eruption of Etna in 1669 - Doc. www.italysvolcanoes.com - The cradle of volcanology

On March 8, the earth trembles near Nicolosi. On March 11, a nine-kilometer radial crack opens ... six mouths will build on the crack!

In the following night, large quantities of lavas are emitted in the lower part. In about 20 hours, the flow drowns the city of Malpasso ... Fortunately, the 8000 inhabitants fled in time.

On March 12, seven more mouths open and then coalesce and form a crater that has a very high explosive activity. The wind will carry the ashes to the southern tip of Sicily. Little by little, the largest adventitious cones of Mount Etna are built : the Monti Rossi.

Map of the SSE flank of Etna with the 1669 flows in pink - in green, urbanized areas, including Catania (dark green barred); in brown, the sedimentary subsoil of Etna. - Map extracted from www.italysvolcanoes.com - The cradle of volcanology

Map of the SSE flank of Etna with the 1669 flows in pink - in green, urbanized areas, including Catania (dark green barred); in brown, the sedimentary subsoil of Etna. - Map extracted from www.italysvolcanoes.com - The cradle of volcanology

The lava continues to gush out of the complex and the flows, divided into three arms, destroy a dozen localities. The eastern branch of the lava flow crosses Misterbianco on March 25 before diving into a depression, the "Gurna di Nicito" occupied by a lake; violent explosion occurs on the same day at the summit crater, announcing the partial collapse of the cone.

The lava flow will fill the depression, then resume its advance towards Catania that reaches the 15 of April. It bypasses the city and arrives on 23 to the sea ... and advances there of 1500 meters.

Winchilsea, Heneage Finch 3d earl of (1689). A true and exact relation of the late prodigious earthquake & eruption of mount Aetna, or Mote-Gibello. London Printed by T. Newco

Winchilsea, Heneage Finch 3d earl of (1689). A true and exact relation of the late prodigious earthquake & eruption of mount Aetna, or Mote-Gibello. London Printed by T. Newco

On April 30, a breach opens in the wall of Catania, lava engulfs. The lava will submerge in the following days the western part of the city ... people try to oppose this invasion of lava, build derisory roadblocks, try to lock the river into dead ends. But another part of the ramparts gives way and the lava surrounds "Castel Ursino", located at that time on a cliff bordering the sea ("U" on the map). It will be relegated to one kilometer in the land, its moat filled with lava.

The eruption stopped in July 1669. In total, Etna emitted a volume of lava estimated between 0.5 and 1 km³, and about 0.25 km³ of pyroclasts. The lava field covers 37 km².

Lava "cicirara" containing centimeter plagioclase crystals (1600-1669) - photo Travelmarx blog

Lava "cicirara" containing centimeter plagioclase crystals (1600-1669) - photo Travelmarx blog

The eruption of 1669 probably drained a superficial magmatic reservoir, present for decades, as evidenced by the presence of abundant centimetric crystals of plagioclase (found in the lavas between 1600 and 1669). These lava are called "cicirara", translatable by "chick pitch", because of the appearance of the crystals. Etna will no longer produce "cicirara" after 1669. (Corsaro & al., 1996)

The eruption of 1669 - Doc.Meteoweb

The eruption of 1669 - Doc.Meteoweb

Sources:

- Etnalife - Etna eruzione1669, al via the celebrazioni nel 350 ° anniversario - link

- Italy's volcanoes - The cradle of volcanology - The 1669 eruption - link

- Etna vulcanologia: The erruzione del 1669 - by Dr. Salvatore Caffo 

- Guide to the volcanoes of Europe and the Canaries - by Mr. Krafft and Larouzière - ed. Delachaux & Niestlé

- On Etna - by Haroun Tazieff - ed. The Odyssey / Flammarion - eighth chapter.

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Publié le par Bernard Duyck
Publié dans : #Historical eruptions

Landslides on volcanic islands are dangerous geological phenomena, capable of generating tsunamis that can spread far from their sources ... the last one to come to mind is the one that recently hit Anak Krakatau.

A study published in Scientific reports investigated the collapse of the north-west flank of Stromboli in the Aeolian Islands; between 1343 and 1456, they were the cause of tsunami that reached the coast of Campania.

This interdisciplinary work is linked to volcanological and archaeological skills on the ground.

(the National Institute of Geophysics and Volcanology (INGV), the Department of Earth Sciences of the University of Pisa, the Italian Universities of Modena-Reggio Emilia and Urbino, the National Research Council (CNR), the City University and the American Numismatic Society of New York.)

(A) General map of Stromboli showing the studied area in the red zone. The inset shows the location of Stromboli in the Tyrrhenian Sea. (B) Aerial view, from north to south, of Stromboli (Google Earth image), showing the location of the trenches and the archaeological site of San Vincenzo. - Doc. references in sources

(A) General map of Stromboli showing the studied area in the red zone. The inset shows the location of Stromboli in the Tyrrhenian Sea. (B) Aerial view, from north to south, of Stromboli (Google Earth image), showing the location of the trenches and the archaeological site of San Vincenzo. - Doc. references in sources

It was known that Stromboli was capable of producing small tsunami, as in December 2002, but the study shows its ability to produce much larger tsunamis that can reach very distant coasts.

The oldest event of greater magnitude took place in 1343: responsible for the rapid abandonment of the island, this tsunami is linked with the destruction of the ports of Naples and Amalfi.

It is narrated by Francesco Petrarca (Petrarch 1304-1374), Florentin poet and humanist, on an embassy mission of Pope Clement VI to Naples, and who as a witness, reported the episode in a letter, where he describes a violent sea storm on 25 November 1343 ... attributed today to the arrival of several waves of a tsunami generated by a landslide on Stromboli.

Following an intense eruptive activity and collapse, the island was abandoned in the first half of the 14th century, until the end of the 16th century, despite its important role in trade in the Mediterranean sea.

Stromboli - the sequence of tephra and tsunami in trench 3 - The T2 consists of two beds of red and black lapilli terebris and an ocher-colored bed, linked to the tephra deposit resulting from an explosive activity at the craters at the top, as well as dust fallout from a landslide. - T1 is a fine ash deposit, prior to the tsunami - Upper Tsunami (Utd); Intermediate sandy bed (Itd); Lowermost bed (Ltd) - The red arrow indicates a ceramic tile. - Doc. references in sources

Stromboli - the sequence of tephra and tsunami in trench 3 - The T2 consists of two beds of red and black lapilli terebris and an ocher-colored bed, linked to the tephra deposit resulting from an explosive activity at the craters at the top, as well as dust fallout from a landslide. - T1 is a fine ash deposit, prior to the tsunami - Upper Tsunami (Utd); Intermediate sandy bed (Itd); Lowermost bed (Ltd) - The red arrow indicates a ceramic tile. - Doc. references in sources

This study, essentially scientific, has no immediate implications.

It first reveals the impact of repeated adverse natural events on a small human community, and its inability to overcome the additional effects of earthquakes and coastal tsunamis.

On the other hand, it points to a higher than expected exposure risk of tsunami  for people living near the southern coast of the Tyrrhenian Sea (Campania, Calabria and Sicily).

The discovery of three catastrophic collapses of the Sciara del Fuoco, during a relatively recent and short period, indicates an underestimated danger so far.

The frequency of collapse of the flank of Stromboli, the maximum volume of these, and that of a volcanic eruption on a large scale, all these parameters must be studied to assess the hazards at the regional scale.

 

Source: Nature Scientific Reports - Geoarchaeological evidence of Middle-age tsunamis at Stromboli and consequences for the tsunami hazardin the southern Tyrrhenian sea - by M. Rosi & al. - under a Creative Commons Attribution 4.0 International License

Stromboli - North zone of archaeological excavations - sign of occupation of the island at an unsuspected time - Doc. references in sources

Stromboli - North zone of archaeological excavations - sign of occupation of the island at an unsuspected time - Doc. references in sources

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