Volcanic island

“ I say that we are on a volcanic island, formed by a mountain rising out of the sea and pouring out its streams of lava, and throwing up its blocks and stones and cinders.”
“What about the coral, then? The place is covered with scattered blocks.”
“Oh, those were carried in by the great wave,” continued Panton. “Once an island like this is thrust up from the bottom of the sea, the coral insects soon begin to be busy and build all round it. Look at the reef yonder.”
“Then you think the volcano is in the middle of the island?” said Drew, taking out his pocket lens to examine a tiny blossom. ”

“ Those who have beheld a volcanic island situated under an arid climate will at once be able to picture to themselves the appearance of Ascension. They will imagine smooth conical hills of a bright red colour, with their summits generally truncated, rising separately out of a level surface of black rugged lava. ”

“ If these facts be not merely accidental, we see that many scattered volcanic islands and small groups are related not only by proximity, but in the direction of the fissures of eruption to the neighbouring continents—a relation, which Von Buch considers, characteristic of his great volcanic chains.
In volcanic archipelagoes, the orifices are seldom in activity on more than one island at a time; and the greater eruptions usually recur only after long intervals. ”

“ If the volcanic mass should subsequently subside, as it is likely to do, the minute ocean builders will continue their work—unless the subsidence be too rapid for their powers of production—and in this way ring-like islands of coral may in time rise from great depths of sea, their basis being the volcanic island which has sunk from near the surface far toward old ocean’s primal floor. ”

“ At the same time Augustin and two other previously quiet islands on the peninsula of Alaska began simultaneously to emit smoke, dust and ashes, while a reef running westward and formerly submerged became elevated to the sea surface. Other islands, of origin exactly similar to Bogosloff and those mentioned, are to be found in this region, notably Koniugi and Kasatochi, in the western Aleutians, and Pinnacle Island, near St. Matthew Island. Indeed, the volcano of Kliutchevsk, which rises to a height of over 15,000 feet, is really a volcanic island. ”

“ The complexion of it whilst the sky was in shadow had so much of the meerschaum-like tint of the island that one easily took it to be a mass of lava identical with the rest of the volcanic creation; but the sun was now pouring his brilliant white fires upon it, and I noticed a deal of sparkling in it as though it were coated with salt or studded with flints of crystal, whilst the bed in which it lay and the slope round about were of a dead, unreflecting pale yellow. ”

“ This island is entirely composed of volcanic matter, in some places alternating with submarine productions. The principal mountain is situated at the western end of the island; it is an exhausted volcano, called in books of navigation, charts, &c., Mount Misery. The summit of this mountain is 3,711 feet above the sea; it appears to consist of large masses of volcanic rocks, roasted stones, cinders, pumice, and iron-clay. The whole extent of land, to the sea-shore on either side, may be considered as the base of this mountain, as it rises with a pretty steep ascent towards it ”

“ We have already described the island of Hawaii, the great volcanoes of the Sandwich Islands chain, and besides these there are in the North Pacific the Ladrone Islands, lying east of the Philippines.
Some of the principal remaining islands are: the Fejee Islands, which are volcanic, with numerous hot springs and craters. The Friendly Islands, with the peak of Tafua, 2,138 feet high, an active volcano with a large crater always burning, and two other volcanoes, Apia, and Upala. Tahiti, to the east, is at present extinct. ”

“ In the island of Late, lying to the west of Vavau, a new volcano broke out with great violence in 1854; the roar of the volcano was heard at Lifuka, fifty miles away; the immense pillar of smoke was visible by day and the fire by night. The central portion of one side of the mountain (about 2500 feet high) was completely blown out by the explosion. [5]
But not only have new volcanoes appeared or long extinct volcanoes resumed their activity within the last century in the existing islands, new islands have been formed by volcanic action. ”

“ Roto Mahana.—In a northerly direction from Tongariro, and distant from the coast by a few miles, lies in the Bay of Plenty the second of the active volcanoes of New Zealand, the volcanic island of Whakari (White Island) , from the crater of which are constantly erupted vast masses of steam clouds. The distance between these two active craters is 120 nautical miles; and along the tract joining them steam-jets and geysers issue forth from the deep fissures through which the lava sheets have formerly been extruded. Numerous lakes also occupy the larger cavities in the ground ”

“ It is not in our power to determine by what various accidents a nation so flourishing, could be reduced in number, and degraded to its present indigence. But we are well convinced that many causes may produce this effect, and that the devastation which a volcano might make, is alone sufficient to heap a load of miseries on a people confined to so small a space. In fact, this island, which may perhaps, in remote ages, have been produced by a volcano, since all its minerals are merely volcanic, has at least in all likelihood been destroyed by its fire. ”

“ April 1838, accounts are given of a series of volcanic phenomena—earthquakes—troubled water—floating scoriae and columns of smoke—which have been observed at intervals since the middle of the last century, in a space of open sea between longitudes 20 degrees and 22 degrees west, about half a degree south of the equator. These facts seem to show, that an island or an archipelago is in process of formation in the middle of the Atlantic: a line joining St. Helena and Ascension, prolonged, intersects this slowly nascent focus of volcanic action. ”

“ The appalling eruption of this volcano in May, 1902, was one of the greatest disasters of modern times and cost the lives of 40,000 people. About one-third of the island’s surface consists of extensive plains, most of them occurring in the south. The soil of the northern part is of volcanic formation, while in the south it is composed of clay. ”

“ There are a great many islands scattered along the coast, many of which bear marks of recent volcanic eruptions, the lava on some being quite fresh; and one (White Island) is even at present an active volcano continually smoking, and chiefly composed of sulphur and pumice, The outline of the coast is exceedingly broken; generally the cliffs are high, but rarely perpendicular; and until after passing the Thames all are of a dark colour, without a trace of stratification. Several of the hills are said by the natives to have lakes on their summits, probably the craters of extinct volcanoes. ”

“ Of the smaller Pacific islands that are not mere coral reefs and atolls the Hawaii group, the Marquezas, Tahiti, Easter Island, Pitcairn, the Samoa, Tonga, and Fiji groups, the New Hebrides, most of the Ladrones, and one or two of the Caroline Islands are volcanic, high, and of recent formation, even though like the New Hebrides and the Marquezas they may rest on submerged extensions of sunken lands. The Solomon Islands are also mainly volcanic, but with the Bismarck archipelago practically form an extension of New Guinea ”

“ Down the centre and out each spur are high volcanic mountains, two of them smoking volcanoes, all pitted with caves and hot springs whose course can be traced in winter by the runnels of steam {85} down the mountain side. On the south side, reefs line all approach. North, east, and west are countless abrupt inlets opening directly into the heart of the mountains down whose black cliffs shatter plumes of spray and cataract. Not a tree grows on the island. ”

“ In the East Indian islands there are great numbers; Sumatra, Java, and the Molucca islands, possess some of the finest volcanoes now existing. You know, from Humboldt, how numerous they are on the western side of South America and Mexico; and Nootka Sound, in the 50th degree of north latitude, was observed by Captain Cook to be entirely volcanic. In the Pacific Ocean, Easter Island is a mere mass of lava and basalt ”

“ All the colonists went down to the shipyard and worked steadily all day without giving too much thought to the volcano, which could not be seen from the beach before Granite House. But once or twice heavy shadows obscured the sunlight, and, as the was day perfectly clear, it was evident that thick clouds of smoke were passing between the sun’s disc and the island. Smith and Spilett noticed these sombre voyagers, and talked of the progress that the volcanic phenomenon was making, but they did not cease work. ”

“ All round the Sandwich Islands the sea has a depth of from 2,000 to 3,000 fathoms, and the island-group culminates in several volcanic cones which rise to the height of nearly 14,000 feet above the sea-level. The volcanoes of the Sandwich Islands are unsurpassed in height and bulk by those of any other part of the globe. ”

“ The beds of the streams and rivers, which swell into torrents during the rainy season, consist of stones and gravel, often of a flinty nature, and often also containing particles of iron. Some basaltic appearances in one of the districts into which the island is divided, and several precipices among the mountains, evidently produced by sudden violence, indicate the volcanic origin of this highly favoured country. There is plenty of good water to be had over all the island. ”

“ No doubt some one island in most small volcanic archipelagoes is apt to be considerably higher than the others; and in a similar manner, whatever the cause may be, that on the same island one vent is generally higher than all the others. Von Buch does not include in his class of volcanic chains small archipelagoes, in which the islands are admitted by him, as at the Azores, to be arranged in lines ”

“ I don’t like to think that I may be wasted.”
“You seem as if you rather hoped we should find savage cannibals upon the island!”
“No, Tilly; I hope we shall not. I believe we shall not. Man-eaters are rarely found in this latitude. My impression is that the island is not inhabited at all. Probably it is of recent volcanic origin. If so, we may have a chance to examine a newly-formed crater. I have longed to do so for years.”
15 “We might as well be eaten as to be blown up and burned up by a volcano,” said Matilda. ”

“ Along a great line, a mighty fracture in the surface of the globe, stretching north and south through the Atlantic, we find a continuous series of active or extinct volcanoes. In Iceland we have Oerafa, Hecla, and Rauda Kamba; another in Pico, in the Azores; the peak of Teneriffe; Fogo, in one of the Cape de Verde Islands: while of extinct volcanoes we have several in Iceland, and two in Madeira; while Fernando de Noronha, the island of Ascension, St. Helena, and Tristan d'Acunha are all of volcanic origin. ("Cosmos," vol. v., p. 331.) ”

“ Earthquake shocks are frequent all over the islands, and it is believed that New Zealand was rent midway, where Cook's Strait divides the North from the South Island, by volcanic explosion. There is known to be an extinct volcano at the bottom of the strait, in front of the entrance to the harbor of Wellington, over which the water is never absolutely calm and where it sometimes boils like a caldron. ”

“ An hour before I had been cutting steps in the last slopes of the last ash cone [Pg 239] of the volcano which still lives and may burst into activity at any fatal moment.
To stand upon the Peak and look down upon the world and the sea gives one a great notion of the making of things. Once the world was a crucible. The islands are all volcanic, all ash and cinders, lava and pumice. But I perceived that the Peak itself, the final peak, the last five thousand feet of it, was but the last result of a dying fire—a mere gas spurt to what had been. The whole anatomy of the island is laid bare ”

“ Like Oahu, the island of Hawaii is entirely of volcanic origin. The two large volcanoes on this island, Mauna Kea and Mauna Loa, formerly had craters at the tops, which have soiled over, and new craters have opened up far down the mountainsides. In many places the surface of the ground is nothing more than lava, still in the exact condition the latest eruption has allowed it to cool in, and seamed with fissures that opened up as it cooled. ”

“ In the far North, however, volcanic action has been slower in dying out. Iceland, with no less than twenty active volcanoes, is still the most considerable centre of such operations in Europe. The huge volcano on Jan Mayen island, between Greenland and Spitzbergen, is still in action. Among the submerged peaks in the northern seas explosions still now and then occur, as in 1783, when a small island was thrown up near Cape Reykianes, on the southern coast of Iceland, and sank again after a year. ”

“ In later times, however, the volcano appears to have exploded and destroyed the northern part of the crater rim, out of the break in which there flowed a tongue-shaped mass of lava which now constitutes the northern half of the island. The last volcanic activity issued from a small ash-cone in the cup of the old crater, and then the island lapsed into its unbroken quietude.
A luxuriant growth of cocoanut palms, and forest trees now covers the old lava, while coarse grass grows rankly over the ash slopes of the crater. ”