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Mount Etna

Mount Etna (or Aetna) is an active volcano on the east coast of Sicily (Italian Sicilia), close to Messina and Catania. It is 3,340 m (10,958 ft) high. On the safe part of its hills a famous wine is produced.

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Mount Etna -- Its appearance and height

Mount Etna may well be called the Queen of European Volcanoes, so majestic does she look, with her lofty summit glistening in the sunbeams white with snow, yet pouring forth volumes of vapour. This mountain, as you will observe from the annexed woodcut, is altogether more massive in its appearance than Vesuvius. It is about three times higher, rising to nearly eleven thousand feet above the level of the sea, and it has a circuit of about eighty- seven miles at its base.

Ancient eruptions -- Pindar's allusion

Etna has been a volcano from time immemorial; but of its more ancient eruptions only vague traditions have survived. The Greek poet Pindar is the earliest writer who makes mention of its activity. He refers to it in his First Pythian Ode, Strophe B, 1. 1. The passage is thus rendered by Carey--

From whose caverned depths aspire,
In purest folds upwreathing, tost
Fountains of approachless fire--
by day a flood of smouldering smoke
With sullen gleam the torrents pour

The ode in which this allusion occurs is said to have been written about B.C. 470; and the eruption to which it refers probably took place shortly before that date.

Virgil's Description

Virgil also describes the mountain very forcibly in the Æneid, lib. iii. 570. Dryden renders the passage thus:--

The port capacious, and secure from wind,
Is to the foot of thund'ring Etna joined.
By turns a pitchy cloud she rolls on high:
By turns hot embers from her entrails fly,
And flakes of mounting flames, that lick the sky.
Oft from her bowels massy rocks are thrown,
And shivered by the force come piece-meal down.
Oft liquid lakes of burning sulphur flow,
Fed from the fiery springs that boil below."

Since the one to which Pindar alludes, there have been recorded about sixty eruptions; but in the present century Etna has been less frequently active than Vesuvius.

Subordinate cones and craters -- Caverns

Owing to the great height of Mount Etna, the lava seldom rises so far as to flow from the summit. It more frequently bursts forth from the flanks of the mountain; and in this manner there have been formed numerous smaller cones, of which several have craters of their own. Hence Etna is rather a group of volcanoes than a single cone; but all these subordinate volcanic hills cluster round the flanks of the great central summit. Etna may thus be regarded as a fertile mother of mountains, with all her children around her. Some of these hills, her offspring, are covered with forests and rich vegetation--such having enjoyed a lasting repose. Others are still arid and bare, having been more recently formed. Owing to this peculiarity in its structure, Etna does not present that conical aspect which characterizes most other volcanoes. Strange as it may seem, there are, on the sides of the mountain, caverns which the Sicilians use for storing ice. Some of these caverns are of vast extent. One called Fossa della Palomba measures, at its entrance, 625 feet in circumference, and has a depth of about 78 feet. This great cavity, however, forms merely the vestibule to a series of others, which are perfectly dark.

Val del Bove

Another striking feature of Mount Etna is the Val del Bove. It is a deep valley, presenting, when viewed from above, somewhat of the appearance of an amphitheatre, It stretches from near the summit down to the upper limit of the wooded region of the mountain, and has a remarkably desolate aspect--presenting a vast expanse of bare and rugged lava.

Formation of Monti Rossi

Of the numerous eruptions of Etna, one of the most memorable was that of 1669, when on the flank of the mountain above Nicolosi, about half way between Catania and the top of the great crater, there was formed an immense rent about twelve miles long, from which a vast torrent of lava descended. After flowing for several miles, and destroying a part of Catania in its course, it entered the sea, and formed a small promontory, which has since proved very useful as a breakwater. But besides this stream, there were at the same time thrown up such immense quantities of ashes, cinders, stones, and other matters, that they formed two conical hills, more than three hundred feet in height above the slope of the mountain from which they rose, and measuring nearly two miles in circumference at their base. These hills were named Monti Rossi.

Eruption of 1852 -- Whirlwinds -- Lava torrents

Mount Etna was in activity as lately as 1865; but a previous eruption in 1852 was of greater violence. It began, as usual, with hollow underground rumblings, and the ascent of dense columns of vapour, mingled with dust and ashes, high into the air. These were speedily whirled into enormous eddies by fierce whirlwinds. Two new mouths were formed on the side of the mountain, and these vomited forth immense streams of lava, which rushed with the vehemence of a torrent down the steep. The violence of the commotion increasing, the two mouths were, by the crumbling of the intervening rocks, blended into one, and then huge fragments of the broken rock were hurled to a great height, along with vast quantities of hot stones, cinders, and black sand. Increasing quantities of lava were now poured from the greatly enlarged opening, and these formed on the plains below a great river of liquid fire, nearly two miles in breadth, and between seven and eight feet in depth, which advanced at the rate of upwards of a hundred feet in an hour, carrying before it devastation and ruin. Its course being through a highly cultivated country, the damage it inflicted was immense. This eruption continued for several months, with only short intervals of rest.


Pictured above was the Mt. Etna ash plume of October 2002 as it appeared to astronauts on the International Space Station. The view looks toward the southeast. Light colored smoke is due to forest fires caused by lava on the volcano's north face.

A more detailed version of this image (1 MB, 3000x2000 pixels) can be found here

Cascades of lava

It has more than once happened, that the lava-streams of Etna, in their descent from the crater of eruption, have come to a precipitous wall of rock, over which they have plunged in a cascade similar to that formed by the lava of Vesuvius in 1855, but on a less magnificent scale, as respects the height of the fall. One of these occasions was during the eruption of 1771, and another during that of 1819.

Description of crater

The principal cone of Mount Etna was ascended in 1834 by Messrs. Elie de Beaumont and Leopold von Buch. The former describes what they saw in the following terms:--"It was to us a moment of surprise difficult to describe, when we found ourselves unexpectedly on the margin--not, indeed, of the great crater--but of an almost circular gulf, nearly three hundred feet in diameter, which does not touch the great crater save at a small part of its circumference. We peered eagerly into this nearly cylindrical funnel; but vain was our search into the secret of its volcanic action. From the almost horizontal tops of the nearly vertical steeps, nothing can be descried but the upper cone. On trying to reckon those one below another, vision becomes gradually lost in the perfect darkness beneath. No sound issues from this darkness. There are only exhaled slightly sulphurous white vapours, chiefly steam. The dismal aspect of this black and silent gulf, in which our view was lost--its dark moist sides, along which crept, in a languid and monotonous manner, long flakes of vapour of a sombre gray--the great crater to which this narrow gulf is attached, with its confused heap of diverse substances, coloured yellow, gray, red, like the image of chaos--all presented around us an aspect quite funereal and sepulchral."

Empedocles

The French geologist, in having escaped from his visit to the crater with nothing worse than a fit of the vapours, came off better than Empedocles, the Sicilian philosopher, in the days of old: for, as the story goes, this inquisitive sage, being very anxious to have a peep into the crater, and venturing too near, toppled in altogether, and nothing more was seen of him, except one of his sandals, which was vomited up by the volcano--thus conveying to his friends an intimation of the manner of his death.

Enceladus

Some incredulous persons allege that this story has no better foundation than the fable of the poets, that the giant Enceladus, son of Titan and Terra, having offended Jupiter, the infuriated god first felled him with a thunderbolt, and then put Mount Etna as a sort of extinguisher on the top of him--his restlessness underneath fully accounting for all the commotions of the mountain.

Craters of 1865

Soon after the eruption which took place towards the end of January 1865, the craters then opened were visited by M. Fouqué, a French geologist. At the time of his visit, 10th March, they were seven in number, and he thus describes their modes of action:--

"The three upper craters produced two or three times a minute, powerful detonations like thunderclaps. The lower craters, on the contrary, incessantly gave forth a succession of reports too rapid to be reckoned. These sounds, although unremitting, were clear and distinct, the one from the other. I can find no better comparison for them than the strokes of a hammer falling on an anvil. Had the ancients heard a similar noise, I can readily conceive whence arose the idea of their imagining a forge in the centre of Etna, with the Cyclops for workmen."

Cyclopean Isles -- Homer's legend

Off the eastern coast of Sicily, and not far from Mount Etna, lie the Cyclopean Isles, of one of which the annexed woodcut gives a representation. You will observe what a singular appearance it presents, with its rows of basaltic columns piled one above another. The other isle is close by, and there is an ancient tradition that they at one time formed part of the mainland of Sicily. Homer has a curious story about the manner in which they became detached. The passage occurs towards the end of the ninth book of the Odyssey. He tells that, at the time Ulysses visited Sicily, it was inhabited by the Cyclops, who, as already mentioned, were said to have had each only one eye, situated in his forehead. Their king's name was Polyphemus, a huge giant who beguiled Ulysses and a portion of his crew into a cave, where he killed some of the crew and devoured them for his supper. Ulysses, fearing his turn might come next, persuaded Polyphemus to taste some strong wine he

had with him, and filled him so tipsy that he fell fast asleep. While he was in this state, Ulysses burnt out his one eye with a red-hot iron. The giant awoke in agony, but Ulysses contrived to escape from his clutches, and, after getting into his ship, began taunting and jeering the monster. Thereupon Homer says:--

     "These words the Cyclops' burning rage provoke:
      From the tall hill he rends a pointed rock;
      High o'er the billows flew the massy load,
      And near the ship came thund'ring on the flood.
      It almost brushed the helm, and fell before:
      The whole sea shook, and refluent beat the shore."

                                     Pope's translation.

The huge missile having thus missed its mark, Ulysses, with great impudence, renewed his jeers, taunting the giant, and telling him who it was that had poked out his eye; whereupon Polyphemus invokes the vengeance of Neptune upon him, and--

     "A larger rock then heaving from the plain,
      He whirled it round--it rung across the main:
      It fell and brushed the stern: the billows roar,
      Shake at the weight, and refluent beat the shore."

                                     Pope's _translation_.

Volcanic origin

The rocks of which the Cyclopean Isles are composed are entirely of volcanic origin, and it is far from improbable that they may have at one time been attached to Sicily, and severed from it by some great volcanic convulsion. A careful examination of these large piles of basaltic columns led Dr. Daubeny to the conclusion, that the lavas from which they have been formed were consolidated under great pressure, and probably at the bottom of the sea, whence they have been afterwards upheaved. He also concludes, from certain appearances, that the two islands were at one time united.

Other basaltic groups

The Cyclopean Isles strongly resemble, in their general aspect, the well-known Giant's Causeway on the northern coast of Ireland, and the Isle of Staffa off the western coast of Scotland. The latter, which, around its whole sea-girt outline, presents ranges of basaltic columns, some of them disposed in curious fantastic groups, most nearly resembles the Sicilian pair. These differ from it chiefly in their having the columns piled in terraces, one above another. Staffa, however, can boast of a far more striking feature --the celebrated Cave of Fingal--its stately basaltic columns inspiring every beholder with admiration, not unmixed with awe, while its brightly-tinted floor rivals in brilliancy of colouring the most beautiful mosaics.

In the Island of Iceland, also, there are some remarkable ranges of basaltic columns. One in particular, named the Ruins of Dverghamrar, is in the form of a semicircle skirting the sea-coast. Another group, still more wonderful, forms a curious natural Gothic arch, surmounted by pinnacles. It is so picturesque that an architect might study it with advantage, and derive from it valuable hints in designing the entrance to a cathedral.



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