By ERIKA SOUTHEY
EARLY signs of Etna’s (Aetna) violent nature could be seen in some verses of a poem by Publius Vergilius Maro written about 100 BC.
“Here, while from Ætna’s furnaces the flame
Bursts forth, Enceladus, ’tis said, doth lie,
Scorched by the lightning. As his wearied frame
He shifts, Trinacria, trembling at the cry
Moans through her shores, and smoke involves the sky.
There all night long, screened by the woods, we hear
The dreadful sounds, and know not whence nor why,
For stars are none, nor planet gilds the sphere;
Night holds the moon in clouds, and heaven is dark and drear”
Centuries later – volcanologists and scientists have a better understanding of the behaviour of this enigmatic and uniquely formed volcano.
Salvatore Caffo – Chair Volcanologist of Etna Natural Park gave EVT Zone an exclusive glimpse into the many features of Mt Etna.
Situated north-east of Sicily Mt Etna is the largest European volcano covering over 1260 Km2. Being an active volcano – Etna is being monitored closely for any change in its general pattern. (Recent activity report is at the end of this article).
A popular tourist destination – Etna completes the beautiful Sicilian landscape hiding its true nature under lush green vegetation and a seemingly quiet slope. Just underneath is a hype of volcanic activity.
Etna was born about 600 000 years ago when the African Lithosphere plate to the south collided with the European-Asian plate to the north. This caused fragmentation of the earth’s crust and created a mosaic of almost stable micro plates from which Etna arose to the South.
Etna’s geologic make-up is unique to that of other volcanoes. How?
Caffo explains: “Its magmas show peculiar and unique petrologic and geochemical features, related to the very complex structural setting of the Central Mediterranean area.”
“The presence itself of the volcano in the geodynamic setting related to the eastern part of Sicily is absolutely unique, as the features of the source and of the original magmas appear as being extremely similar to the ones of volcanoes forming in the oceans as submerged sea mounts and islands; whereas Mount Etna has grown on continental crust at the intersection of major fault belts and at the front of a complex south-verging mountain range.”
Etna’s structure still puzzles many said Caffo: “There still is a matter of intense debate among volcanologists, structural geologists, geophysicists and other earth scientists.” Geodynamics is the science of the forces at work within the earth.
A stark contrast; Etna the killer that at any time can destroy life within several miles of it – also houses several plant and animal species. Mt Etna – spans centuries of human, animal and plant existence that show tell-tale signs of how this area evolved through the ages.
Etna brings with it; a rich history of agricultural life which Caffo and his team are trying to preserve at best despite the obvious threat of the volcano’s constant activity, climate change and the ‘human factor’.
Their main objective is to preserve the biodiversity and main wood ecosystems. The Mt. Etna “Nuova Gussonea” botanic garden was set up in 1979 as part of this strategy. It covers a surface of over 10 ha and is situated at 1700m above sea level on the southern face of the volcano in regional forest territory in the heart of the Mt. Etna Natural Park.
Caffo stated: “the botanical garden is destined to host only species and plant communities belonging to the Mt Etna territory” and “it aims to conserve the plant diversity and the in situ and ex situ germoplasm of the Mt. Etna territory. It also promotes the diffusion of scientific knowledge and plays a leading role in the field of environmental education.” ‘Germoplasm’ is a collection of genetic resources for an organism. For plants, the ‘germplasm’ may be stored as a seed collection or, for trees, in a nursery.
To ensure the vision of preserving flora and fauna typical to this area- Mount Etna was proposed for nomination as a European Geopark. It covers an area of 45.000 hectares and it is divided into two areas. Caffo elaborates:
“Area ‘A’ consists of 19,000 hectares – almost all of which is public property. In this area there are no traces of human activity. Virgin territory – it hosts native flora and fauna that includes birds of prey like the Royal Eagle.
Area ‘B’ comprises of 26,000 hectares and consists of small private agricultural fields. It is rich in farm houses and ascetic plantation houses which testimony to the presence of man since ancient times.”
The buffer zone (14.000 hectares lying between 600 and the 800 meters above sea level) is the area where tourist facilities are permitted. This is to limit impact on the landscape and the environment.
Inside the Zone B identified for tourist facilities and ski footsteps is ‘Zone C Altomontane’.
Zona A: 19.237 Ha
Zona B: 25.391 Ha
Zona C: 4.188 Ha
Zona D: 9.551 Ha
Figure 1 – Nominated property and buffer zone Mt Etna Geopark (Copyright Salvatore Caffo)
Illustrating Etna’s dangerous presence – is that the volcano is located in the province of Catania that includes parts of areas belonging to 20 towns: Adrano, Belpasso, Biancavilla, Bronte, Castiglione di Sicilia, Giarre, Linguaglossa, Maletto, Mascali, Milo, Nicolosi, Pedara, Piedimonte Etneo, Ragalna, Randazzo, S.Alfio, Santa Maria di Licodia, Trecastagni, Viagrande, Zafferana Etnea.
Perhaps 18th century Illuminist, naturalist and artist – Jean Hoüel described Mt Etna’s environmental complexity best during a grand tour when he said:
“Volcanoes are the greatest spectacular examples of nature’s forces and Sicily has one of the most important volcanoes: Mount Etna. We can observe all climates from Scandinavian glaciers on the top to the African plains on the base”. “Nevertheless, this place of continuous destructions is beautiful and extraordinary. Uncultivated fields, natural pathways, rivers, rocky lava plains colonized by many plants gave to this special environments an amazing and as well a terrible appearance. A great astonishment follows the observation of this variable and peculiar landscape.”
RECENT ACTIVITY AT ETNA COURTESY OF SALVATORE CAFFO
The last eruptive episode was on 28 April 2013 and is a volcanic paroxistic activity – not an eruption.
The 13th episode of lava fountaining (paroxysm) of this year at Etna’s New Southeast Crater took place on the evening of 27 April 2013. This came one week after the previous episode, and after a “prelude” characterized by Strombolian activity and frequent ash emissions which had started already on 21 April, just one day after the 20 April paroxysm.
After a gradual increase in both the eruptive activity and in the volcanic tremor amplitude, which had started on the evening of 26 April, the paroxysmal phase began shortly after sunset on 27 April, with lava fountains 300-500 m high, emission of lava flows from the south-eastern and north-eastern flanks of the New Southeast Crater cone and from the “saddle” between the two Southeast Crater cones, forming small lava flows toward south and north. A portion of the eastern flank of the cone collapsed, generating a pyroclastic flow, which advanced about 1 km toward the Valle del Bove. Furthermore, a cloud of gas and pyroclastic material formed, which was blown by the wind to the northeast, resulting in ash and lapilli falls in the area of Linguaglossa, and more distant Taormina and Messina. The paroxysmal phase lasted about 2 hours; lava emission toward southeast continued for many hours and ceased during the forenoon of 28 April.
For more information on Mount Etna
http://www.cataniaperte.com/etna/default.htm – Geological History (Italian – used ‘translate page feature’)