William Lord Watts

Across the Vatna Jökull

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News of volcanic Activity

Re-crossing Vaðlaheiði, we reached Ljósavatn (where I had left my baggage and baggage-horses) with the daylight, from whence we proceeded along the Skjálfandifljót to Stóruvellir. The river Skjálfandifljót runs down a broad fertile valley shut in by hills of basalt, which rise in some places as much as 1300 feet above the level of the river. From thence a broad stretch of grass-land, extending some 25 miles long, brought us to Stóruvellir [1] , a flourishing farm surrounded by grass-lands. The people, we found, were all busy hay-making; so I ascended the hills behind the farm to look at the surrounding country, but before I could reach the summit it had clouded over, and I could see but a very short distance. Early next morning a man brought word that a fresh eruption had broken out in the Mývatns Öræfi. This was news indeed, and as it was Sunday, when some of the more distant population would be assembled at the neighbouring church, I despatched Paul to ascertain from them the accuracy of the news. In the meanwhile, however, accompanied by the farmer's son, I ascended the hills to reconnoitre, and when about half-way up I espied a tall dense column of white smoke in the east, which announced the correctness of the intelligence we had received. On arriving at the summit I looked again, and then perceived six smaller columns in a line with the larger one, rising to about half its height. These columns of smoke had evidently originated in the Mývatns Öræfi, and rose in perpendicular columns, which spread out at the apex like phantoms of giant palm trees in the calm atmosphere of that early autumn Sabbath morning! The position I occupied commanded a magnificent view of the Dyngjufjöll mountains and the Kverkfjöll, both of which volcanoes lie south of the Mývatns Öræfi; neither of these, however, seemed to be particularly disturbed, but the mushroom- shaped cloud of smoke which had been there all the summer still hovered over the Dyngjufjöll. There appeared, however, no increase in the three thin columns of vapour I had before observed rising from the Kverkfjöll. Looking in another direction I found the country to the east obscured by what seemed to be a fog, which was, probably, vapour and ashes from the fresh eruption drifting slowly towards the Vatna Jokull. Presently the large volume of smoke from the Mývatns Orrefi disappeared, leaving in its place a cloud of thin black vapour, but before many seconds had elapsed it again sprang up in three distinct bursts to more than its former height. Hastily descending, I ordered the horses to be saddled, and at once we rode away at full gallop towards the seat of the new eruption.

By evening we reached the farm of Grænavatn, where I had the pleasure of again seeing Thorlákur and his brother-in-law, and I forthwith made preparations for visiting the point of volcanic activity the following morning, but my plans were frustrated by a violent storm of rain, wind, and snow, which made it a matter of impossibility to cross the hills so, chafing at the delay, I was compelled to postpone my expedition. During the previous night a man had arrived from Grímstaðir, upon the eastern side of the Mývatns Öræfi, and reported that between ten and eleven o'clock on Sunday morning, August 15th, a smart shock of earthquake was felt at that place, travelling from north-east to south-west, while almost simultaneously columns of smoke were seen upon the plain of Mývatns Öræfi, and forth- with an eruption commenced from the same place as in the previous spring. Upon the 17th the storm had sufficiently abated, so, accompanied by Jón, who had been my guide to Fremri-Námur, I set out for the eruption. Upon entering a valley in the mountains of Mývatn, by which we intended to gain access to the Mývatns Öræfi, a few columns of smoke in the distance warned us that the eruption lay before us, and as we emerged from the glen, a line of some twenty columns of smoke burst upon our view, while at the north end lay two clusters of black mounds in close proximity. From the most southerly of these sprung up two columns of dense black smoke, which struggling to ascend, were beaten back to earth again by the wind in a foul heavy mist that spread itself out for miles over the lava streams, both old and new, which lay to eastward, clinging to the higher crags in dark, ominous-looking masses, and obscuring large patches of the more level plain. From its neighbour to the north a high column of stones, ashes, and dust proclaimed the principal volcanic vent, and as we gazed upon the scene, suddenly, with a roar, every particle seemed on fire, while explosion after explosion hurled the larger fragments to a height beyond our view in the dense canopy of vapour which hung over us, making the ground upon which we stood and the rocks around us tremble. While the lava sloped over the most northerly side, the large column of fire sank, and only stones and cinders were ejected. This column of débris I noticed continually varied both in size and volume, sometimes clustering like a large swarm of bees in the smoke, apparently scarcely a hundred feet above the crater, while at other times it shot up into a tall column with explosive violence, the masses of scoriaa shrieking in their passage through the air. This was followed by a calm, and then again by a rending sound, as a new crater opened on the north side of the mound which ejected a stream of white hot lava that tumbled in a cascade of fiery froth upon the old lava stream of the previous spring. At this point a dense smoke and the sound of splitting rocks marked its progress till it oozed in bright red viscous masses through the interstices of the older lava, forming pools beyond the limit of the elder stream, which glowed for a moment only and then turned black. As we looked on these wonderful changes of the face of nature, a dim twilight supervened, although only six p.m., so we stopped upon a patch of wild oats which grew profusely upon many parts of these sands, and here we left our horses to feed while we took our evening meal upon a sand-bank commanding a full view of the eruption, which was rather more than a mile away. The scene was grand, but our horses did not appear to be particularly frightened at the eruption, for after standing some time looking at it, they quietly went on grazing.

Volcanic Eruption

On approaching the volcano as closely as the heated lava would allow, I found it to consist of a cluster of black mounds, describing together an irregular cone, from the centre of which, and probably towards the termination of the spring". eruption, a large crater had been formed, apparently little more than half-a-mile in circumference; its northern wall had now evidently been broken down, while from the centre rose the conical walls of the crater then erupting. There was a breach also in the north side, from which the lava poured at intervals, while numerous cracks in the walls of the cone caused the glow from the intense burning within to shine through with such brilliancy as to give the summit the appearance of being wrapped in flames. As I intently examined this, two smaller craters became suddenly visible, one in the north base of the erupting mound and the other some little distance further north, in the lava itself. Both these were burning with a brilliant white light, and emitted a rending, crushing sound, although erupting with little violence. From these two craters the principal lava streams were advancing with considerable rapidity, encircling from time to time patches of ancient lava and sand which formed the plain, and finally overwhelming them in its fiery embrace. As night closed in, the heated lava and the noxious gases arising from it prevented me from getting nearer than within a few hundred yards of the volcano, so I lit my pipe at the nearest lava coulée and returned to camp. There again, while sitting by my tent, upon a high bank of volcanic sand, I gazed for a long time upon the mighty fountains of volcanic fire, which in one continuous stream assailed, the sky with a glorious display of natural pyrotechnics. All through the dark hours of the night the volcano burned and roared, followed by explosion after explosion, which shook the desolate waste around to its very foundation. When I rose at midnight to take another look at this grand and terrible spectacle, it was still energetically erupting with a grandeur the equal of which I may never have another opportunity of witnessing; for the grim sands and lava fields of the Mývatns Öræfi were bathed in an unwonted light which reddened the lurid sky and deepened the shadows amongst the weird crags of lava, rendering them still more unearthly in that fire-blasted wilderness in the midst of which we were encamped. The wind still blew freely from the north-west, from which quarter, fortunately, it had been blowing all the evening, so that I was enabled to reach a neck of land almost encircled with lava within about two hundred yards of the crater which was erupting. From this coign d'avantage I was able to examine minutely the progress of the eruption ; but the heat was very great even at this distance, while my field glass shewed me that the fiery column seemed to be made up of myriads of molten atoms. The whole scene was, in fact, utterly indescribable, yet I could not but reflect how meagre and insignificant was even that glorious display in comparison with those mighty fires which have been occasionally let loose from such mountaius as the Vatna and Skaptar Jökulls, and how terrible! how utterly unapproachable must have been their outburst! Yes, that is the unsatisfactory part about them ; when they are in full working order there is no getting near them, and at other times one can only climb, shudder and freeze over their temporary tombs.

Seat of volcanic Disturbance

However, nothing daunted, at 6 a.m. I started to examine the line of smoking mounds which marked the course of the great fissure or gjá (chasm). As mentioned before, this fissure was formed in the early spring, and re-opened on the 15th August, 1875, to give vent to the volcanic fires which have rifted and contorted the surrounding plain. The erupting mound had grown about 50 or 60 feet in the night, but the eruption itself, as I saw it, was evidently upon the wane. The next cluster of mounds towards the south contained three craters, but the largest was covered with whitish yellow sublimations, probably sulphur and sal-ammoniac. This was tranquilly steaming and had evidently not been disturbed during the recent outburst; in fact, all along the fissure there occurred mounds at intervals, and some were smoking violently, while many other smaller lateral cracks and fissures were likewise smoking, but not to the same extent. These fissures, I noticed, were entirely environed with hot lava, apparently of recent production, and a depression in some places of 50 feet in depth had sunk around them, varying from two to about four miles in breadth, while numerous deep chasms crevassed the adjacent plain. They were mostly parallel to the principal line of disturbance, and as they approached the depression they increased in size and depth, while those in close proximity to it ran into one another where the ground was upheaved by a general chaotic dislocation. The whole line of smoking fissures appeared to me to have erupted lava both during the spring and at the eruption in August; the fissures terminated in a series of cracks, the edges of which were in many places covered with sublimations of sulphur and sal-ammoniac.

On the hot Lava

Aided by a strong north-westerly wind, which had fortunately been blowing throughout my visit to this remarkable spot, and a strong pair of leather boots, I succeeded at one point in traversing the still hot lava, till I reached the principal fissure about half-a-mile from its southern termination. In many places I found it was four or five feet wide, in some places choked with solid lava; and in others gaping widely open, but at some points it was spanned with cinders and lava, encrusted with various sublimations, which showed that there had been no recent outburst in that particular spot. In some places, however, similar accumulations had been scattered around by the recent disturbances, in fragments so variously encrusted that at first sight I was led to suppose the fissure had cast out great quantities of party-coloured cinders; at all events, at all points where the eruption had been particularly violent circles of cinders and clinkers had formed varying from one or two to many feet in height, bridging over the fissure and forming conical mounds wherever the outburst had continued for any lengthened period. This struck me as being rather remarkable, as I should almost have expected to find the clinkers, etc., piled up in banks upon each side of the fissure, instead of assuming, as they did, such regular shapes, often at right-angles with the fissures producing them; but where the fissure was not blocked up it steamed violently, emitting nauseous smells and making hoarse choking sounds. Its depth I could not ascertain, as the emanations which arose from the lava I was standing upon compelled me to beat a hasty retreat, and indeed they made me feel dizzy for the remainder of the day. This gjá is situated in the Mývatns Öræfi, in a line parallel with Lake Mývatn, at the height of a little less than 1000 feet above sea level; its direction is N.N.E. to S.S.W. The length of the fissure is about twelve English miles, and from it has issued a lava stream of about fourteen English miles in length and perhaps three-and-a-half broad upon an average, though it is much narrower at some points than at others, especially towards its southern extremity. This recent lava, both of the spring and autumn, had flowed over the ancient lava and sand, rendering so large a portion of the Mývatns Öræfi a useless desert; while it had particularly overflowed an ancient lava stream, produced by a vent in the west portion of the Mývatns Öræfi, called Svínagjá. The new lava appeared to differ from the old only in this respect, viz., that the ancient lava contained olivine, which the closest microscopic examination failed to discover in the more recent production. I also found that no pumice had been ejected from this fissure up to last August; lava, stones, cinders and ashes only having been thrown up. This spot may be regarded as the northern centre of recent volcanic activity, and the Oskjugjá as the southern, both occurring in the same rectilinear bearing, N.N.E. and S.S.W., and so coinciding with the great fissure which it has been presumed bisects the island from N.E. to S.W.

Carefully taking the bearings of the neighbouring mountains from the south end of the fissure, I made two or three dashes over the hot lava to look into the grim jaws of a chasm which had been erupting with especial violence, where the various heights of the conical mounds gauged the violence and the extent of the eruption; but a very short distance farther north the heated lava became too broad to permit of such excursions with any degree of safety, so I ascended some elevated ground to the west, in order to obtain a bird's-eye view of the seat of erup- tion.

This fissure, as I have before said, extends through a recently-formed depression, in the direction N.N.E. to S.S.W., extending from about one mile north of the road from Grímstaðir to Reykjahlið to a point bearing Jörundr 19° N., Burfell 349° N.W. [2] It had erupted in seven places with great violence, and had formed there conical hills, containing several craters. After inspecting these, I turned my back upon the line of steaming vents, having seen all that could be seen, and I was well contented with my little expedition. After a while we reached our horses by a short cut over the ancient lava, which had flowed partly from the Svínagjá and partly from the Mývatn hills, then returning to Grænavatn, and proceeded thence to Stóruvellir the next day.

[1] Stóruvellir, farm on the left bank of Skjálfandafljót, next to the new bridge. back
[2] Trying to track the absolut bearings on a map (Sérkkort 1:100.000 Húsavík / Mývatn) is difficult and leads to no satisfying result. Magnetic deviatiation may be the reason. Using the realtive angle between the bearings confirms a ponit approximately 2 km SW of the transsection of the old Almannaleið with 15 km long fissure of the Sveinagjá.back

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