Picturesque New Zealand/Chapter 6
The Buried Country—Earthquakes—The World's Greatest Geyser—A Hot Lake—The Wonders of Waiotapu
No trip in the thermal wonderland was more interesting to me than the Round Trip. This tour leads into a buried country, through mud-imprisoned Wairoa, past entombed Te Ariki and MouraMoura,—New Zealand's Pompeii and Herculaneum,—over volcanic Rotomahana Lake and its steaming cliffs to Waimangu, a sand-choked water volcano, and to the gaping summit of fissured Tarawera, which threw red-hot stones and ashes upon the land nearly thirty years ago.
As a volcano, Tarawera was born on the night of June 10, 1886. Assisted by its neighbors, Wahanga and Ruawahia, it darkened the country for many miles with scoria stones, ashes, and dust. For four hours Tarawera rained stone and mud, and with such strength did it burst forth that its explosions were heard as far as Christchurch, five hundred miles away, while flashes of the electrical storm that broke over it were seen in Auckland, one hundred and twenty miles distant. No lava overflowed, but lava walls were formed. Miles away huge earth cracks were made, and Lake Rotorua, fifteen miles beyond, rose several inches. In Tarawera itself and in its vicinity a series of vents formed a fissure nearly nine miles long, from three hundred to fourteen hundred feet deep, and with a maximum width of one and a half miles.
Soon after Tarawera erupted, Lake Rotomahana, two thousand feet below Tarawera's summit, became active. At that time it was a warm body of water, with a thermal, swampy margin, one hundred and eighty-five acres in area, and it discharged into Lake Tarawera, a mile distant. Now Rotomahana is thirty times larger, and its outlet to Tarawera is blocked. Rotomahana is still, as it was then, a discolored lake, and it is completely surrounded with dreary looking mud cliffs, the barrenness of which is relieved only by the waving plumes of the toitoi (pampas grass).
It was not always thus. Under these cliffs lie the White and Pink Terraces, the most beautiful objects of New Zealand's thermal regions before the lake they had overlooked buried them. There they are to-day, shattered and irrecoverable, according to some investigators; entire and little damaged, according to others who are more hopeful than positive. These terraces were high, wide rippled stairways of sinter, smooth and hard. In places they swelled out as umbrella buttresses. In their floors were warm baths, into which tourists and resident Maoris delighted to plunge; over them hung clouds of steam, and under them raged a heat that I found still strongly evident on the site of Pink Terrace.The White Terrace had a fountain of azure-blue hot water ninety feet in diameter, which sometimes spouted ten or fifteen feet high. When the south wind blew
briskly it could be safely entered to a depth of thirty feet, its beautifully encrusted crater meanwhile remaining empty until the wind changed. Then, roaring all the while, it filled at the rate of three or four feet an hour, and when within a few inches of the rim often shot a column of water to a height of sixty feet.
Will Tarawera burst out again with fiery stone? No one knows. Its energy may be exhausted, but it is impossible to overlook its recent birth as a volcano and the fact that it has given but one exhibition of its powers. In New Zealand nothing is more uncertain than speculation regarding volcanic outbursts and earthquakes. New Zealanders, more particularly North Islanders, never know when a town or village in the thermal zone may sink or be showered with burning ashes, or when they may lose a stretch of coast or find it elevated. In both islands earth tremors are frequent.
In Rotorua, where I have been startled by their rending reports, earthquakes are a diversion. They rattle dishes and alarm visitors strolling or playing in the sanatorium grounds; but they are not severe or uncommon enough to frighten the two thousand residents.
Some day Tarawera may be equaled or outdone by Ngauruhoe, or another volcano may appear; but these things do not trouble New Zealanders. There are so many safety-valves in their country that they believe themselves to be reasonably secure from volcanic disturbances. There are thousands of these steam valves from the tiny, noiseless fumarole to the gaping, roaring blowhole and the smoking craters of Ngauruhoe, Ruapehu, and White Island.
The Round Trip is as instructive as it is interesting; to me, visiting Waimangu was like going to school. There I learned theories of thermal and volcanic activity, and I saw them illustrated. The illustrator and teacher was "Bob" (R. H.) Ingle, who often has had more than one hundred pupils in his two daily classes. On this school day, as usual, one class reached Waimangu via Wairoa, the other via the Rotorua-Taupo road. In the creviced wilderness of mud between Waimangu and Lake Rotomahana the two classes met, and the guides exchanged pupils.
In approaching Waimangu via Wairoa, Waimangu's steaming flats and cavities were hidden by mud banks and the walls of the Tarawera fissure. On the commanding elevation where the Government accommodation house stood, a comprehensive view was obtainable, however. Eastward in the distance was the blue line of the Huiarau Range; to the far right, the mountains and hills of Lake Taupo district; and a few miles away, in the same direction. Rainbow Mountain, a variegated mass of rock and clay with steaming cliffs and canyons. Running to the base of all these heights were the desolate Kaingaroa Plains. They looked to be, as they probably are, the remains of a plateau, and they were marked everywhere with isolated, flat-topped bits of land. It was as if a capricious river had cut the plains into thousands of winding channels.
Between Waimangu House and Tarawera stretched enormous deposits of mud. Those running toward Tarawera had been cut by rains into innumerable gravelly furrows, of which many were from ten to twenty feet deep. They were fashioned into sharp ridges and peaks, and thousands of the gray pinnacles were topped by a big bunch of toitoi.
In following Guide Ingle from Waimangu House, we descended almost immediately into Tarawera's fissure. It soon widened into a circle, and in this rose clouds of steam and, from a yellow-white surface stained with iron and sulphur and encrusted with alum, sounds of boiling and sputtering. This was Frying-Pan Flat, and it was well named. In places its surface was so hot that it simmered and bubbled; in other places it was warm; nowhere was it cold. In such a spot it was best to step carefully. The timid among us needed no cautioning, but the rash and careless did. To right and to left were notices reading, "Trespassers on this side of the fence will be prosecuted"; and frequently the guide voiced a warning, and sometimes a command. A young man started off on a little exploration of his own. Ingle saw him, and instantly shouted: "Here, sir; you must not go there. I told you to be careful where you go."
Coming back, the disobedient one stepped on a broken surface, and sunk to his shoe-tops in fuller's-earth.
"Wash it off in that stream," directed Ingle; "it has acid in it." Next a woman ventured alone toward the crumbling verge of Waimangu Basin.
"Hey!" shouted Bob; "come away from there, confound it!"
Frying-Pan Flat was the playground of thousands of small, hot bubbles that rose and broke with a roar every minute of the day and at a very rapid rate. They varied in diameter from a quarter of an inch to an inch, and many threw up tiny drops of clear water from one inch to four inches high. One of these sputtering areas was called the Gridiron. Across its surface were several cracks, caused by an overflow of water from a cold creek in the fissure, and all along these fractures were hot bubbles. The greatest activity on this broken silica crust was at the foot of Gibraltar, a rhyolite cliff one hundred feet high. In miniature it had a rough resemblance to England's fortified Rock; but not in form only was this similarity traceable. The cliff's face was perforated with steaming vents that reminded me of belching cannon.
Into this agitated area we hesitatingly ventured. Stifling steam clouds that filled our lungs with sulphurous fumes enveloped us and caused us to gasp for breath. It was worse than Tikitere, and two or three of the pupils started to retreat.
"Come on," shouted Ingle. "Follow me and you will be all right."
We all dived through, and getting to windward of the vapor, we reached the verge of the "frying" boiler.
"Now," began our instructor, "you are standing in an old crater, one of seventeen that were blown out between here and Tarawera, two of them in 1886. Until Waimangu erupted, this crater was a cold-water lagoon, and, as you see, part of the lagoon remains. Come over here and I will prove to you that the earth did not have to cool before it grew vegetation. The green growth on this rock is algæ, thriving in a temperature of one hundred and fifty degrees. Ten more degrees would kill it. These black pebbles are rhyolite bits coated on the upper side with iron pyrites, and on the lower side with oxidized iron."
Retracing, Ingle led us to where it was clearer, and instructed us in geyser and volcanic action.
"Here is how geysers are formed," he explained. "The cold water constantly running into this hot pool is immediately expelled. And here is the Sponge Cake. The rock beneath its crust has been softened by condensing steam."
Near the Sponge Cake was Ngauruhoe Junior, a small deposit of steaming sand. When Ingle made holes in it with a stick, sand and pebbles were thrown out, and where he pressed it with his foot, a small shower of sand was tossed up a few inches as soon as the pressure was removed.
As we listened to our thermal lecturer, our attention was drawn at intervals to a hoarse roar issuing from a rocky face near Gibraltar. It sounded like an ocean liner letting off steam, and it was emitted by Waimangu Blowhole, a regulator that expelled great quantities of steam more than one hundred feet high. For three minutes it blew steadily, and then was quiet for four minutes. Like the tides, it flowed and ebbed; and, we were astonished to hear, its activity is indeed partly due to the tides, though they are thirty miles away at the nearest point!
Near the blowhole was ample evidence that any day this reserve may suddenly become shifting sand and flying stone. Waimangu Basin, an area of two and a half acres, affords a good illustration of the unstability of the earth's crust in New Zealand's thermal regions. Until a few years ago this depression did not exist, and then the cold waters of the creek caused a change. They penetrated to heated depths, and in 1901 there was a terrific explosion in the stream's bed. At that instant Waimangu, the greatest geyser New Zealand, and perhaps the world, has ever known, was born. The basin is still there, but Waimangu plays no more. On October 26, 1903, it made its last shot, unless, as Mr. Ingle predicts, it is born again. Now its vents are choked with sand, and where there was fifty feet of water there is now very nearly that depth of earth.When Waimangu played, it sent an enormous quantity of water, sand, and stones from fifty to twelve hundred feet high, and once it threw a boulder weighing one hundred and fifty pounds a quarter of a mile. The black body it lifted was half the area of its basin. It had three vents, and when their expulsions met, the united
eruption was vertical; but when they missed connection, there were side shots. One of these killed four New Zealanders, two being women, a few weeks before the geyser ceased playing. This ill-fated party had gone near the pit to take photographs. Suddenly Waimangu shot sideways, directly at them. All were knocked into the creek down which the geyser always poured its flood, and their scalded bodies were carried a considerable distance.
Waimangu's basin is still slightly active. In its alum-sprinkled, sulphur-dyed surface are simmering holes and small spouters and a large muddy pool. These evidences of activity, and a belief that the sand is the main, if not the sole, cause of Waimangu's cessation, have persuaded many theorists that, with assistance, the geyser can be enabled to play again. Acting on this theory the New Zealand Government dynamited the hollow, but without encouraging result.
Adjoining Waimangu Basin was the Inferno, a large pool of hot, blue water at the base of the high cliff on which the abandoned Waimangu shelter shed stood. It was covered with steam, and occasionally muffled "torpedo" explosions disturbed it. When Waimangu was active, the Inferno never failed to rise about fourteen seconds before each outburst of the geyser, but no furious turmoil accompanied the elevations. The Inferno's overflow formed a hot creek, which flowed into Lake Rotomahana, about two miles distant. The channel through which it ran is a dismal place, a rain-sluiced cleft banked high with volcanic mud. In many of these mud crevices, while exploring without a guide, I came suddenly and unexpectedly upon steam vents, and in the creek bed itself I saw two hot-water splashers that mingled their waters with those of the creek.
Rotomahana is one of the so-called hot lakes. There, in a Government launch, I steamed in a hot "sea." Only a small part of the lake was heated, but enough of it was thermal to provide a novel experience. Before the vari-colored cliffs where the Pink Terrace lies buried, the launch ran where geysers vainly tried to lift the water beneath its keel, and where hot springs played and fumaroles hissed and roared. Here the guide drew a pail of water from the lake.
"Put in your hands," said he.
"How hot it is!"
It was a fervent chorus from the class in thermology.
Ashore rose clouds of steam. At the water's edge there was simmering and sputtering, and on the slopes above hot streams ran, broken surfaces sang, small openings steamed like boiling kettles, and the hot breath of shifting, enwrapping vapor caused me to ponder flight.
A few miles south of Rotomahana lies Waiotapu Valley, guarded by steaming mountains. So many sights are there in this vale that it would require days to see them all. Over its scrubby surface run hot-water creeks, and in its siliceous depths are hot baths, colored pools, geysers, sulphur pits and caves, alum cliffs, and a beautiful sinter terrace. The most conspicuous of its wonders is Rainbow Mountain, twenty-five hundred feet high, and composed largely of red and white clay with shades of pink, purple, yellow, and gray, produced by hydro-thermal action. In its slopes are crater hollows with warm springs in their bottoms, and high on its cliffs are steaming funnels. West of it is noisy Mount Maungaongaonga and its powerful blowhole. When very active, this steam outlet can be heard for half a mile. South of Maungaongaonga is Paeroa, another mountain with a heated base; below it is a boiling fountain and a hot stream.
Waiotapu is seen at its best in the early morning, and especially on a frosty one. Steam columns ascend in every part of the vale. There appear to be hundreds of them, lazily rising like fog on a swamp. It is as if a thousand subterranean boilers were discharging their steam through innumerable surface valves.
To the midday traveler the only object of particular interest on nearing the valley's hotel is the Giant Porridge-Pot, a huge mound of splashing mud. It is the largest mud "volcano" in the thermal district, its height above the road being ten or twelve feet, and its active part, from which mud is often hurled several yards, about twenty feet in diameter.
The valley's most interesting part is the Maori Reserve, a white, barren spot opposite to the hotel. The first object shown me here was a deep sulphur pit, a recent collapse that revealed the dangerous nature of the surface. Near this were the Twin Craters, immense cavities formed by sinking. The peculiar action of steam at the bottom of one had gained for it the name of the Paddle Wheel. Close at hand were heated sulphur beds, perforated by steaming apertures with sulphur-discolored mouths. Early in the morning volumes of steam poured from them, but during the day the emissions were small.
Just beyond the Devil's Bridge, a shelf of silica spanning steaming cavities, were the sinter terraces of Champagne Pool, which are rivaled only by the terraces of Orakei-Korako. Of unknown depth, this pool is the largest basin of water of its kind in New Zealand, being, to quote a native guide, "two acres around." Its mineralized waters had formed a white and grayish-white rippled slope several hundred feet long and containing basins of yellow water holding solutions of sulphur and selenium. The precipitations of the pool had for many years added an inch to the surface of the terrace every twelvemonth. In all that time the pool had been covered with steam, and its waters, disturbed probably by gas, had never been quiet. The shores were encircled by a hard, narrow sinter rim built by its ebullitions, which, when combined with a stiff breeze, made the contents look like a choppy sea.
To amuse me my guide, Kiritapu, threw a shovelful of sand into the pool, and almost immediately it began to simmer. This was followed by bubbles which increased in number so rapidly that soon there were thousands of them. Scores of them began traveling round the shores.
"They will go right around," said Kiritapu. And they did.
In a sunken basin near Champagne Pool was Echo Lake, its gray walls lapped with cold, gray-blue water, but in its centre a hot spring or a gas-disturbed area. At one point was a small beach strewn with mud-discolored sulphur beads, produced at the lake's bottom by hot water, and ejected by gas.
The Government Reserve at Waiotapu covers a large area. Through it runs the Waiotapu River, here a small stream, between steaming banks. In deep basins with shattered walls, half hidden by tea-trees, are hot, quiet pools; in other places are gaping depths, long inactive, or showing only whiffs of vapor.
In the midst of this interesting dreariness, concealing its beauty from the ugliness about it, is a fairy-like sulphur cave. Its gray rock roof, softened by condensing steam, is encrusted with sulphur crystals and studded thickly with clear drops of water. The combination looks wonderfully like a yellow frost in which diamonds have been lavishly scattered.
Another unique object in this reserve is Lady Knox, an obliging geyser. This geyser will play for anybody who soaps it; and it will do more—it will blow soap-bubbles. No clay pipe in the mouth of the most zealous soap-blower in the world could produce such a profusion of bubbles as Lady Knox tossed out for me. But it took a bagful of soap-bars to start her.
I had not long to wait for the suds, however. Up they came through the cone-shaped opening, a school of bubbles, each trying to be the first away. The majority broke at the start; others soared away to a height of fifteen or twenty feet, and one floated twenty-five yards before breaking. Some were from two to four inches in diameter. This was well enough for bubble-blowing, but the geyser played only ten feet high, a third as high as it should have gone. The guide investigated.
"Somebody has put a stump into the geyser," said he, in a tone that indicated that he considered it a personal affront.