Art. XLVIII.—Notes on the Eruption of Tarawera, as observed at
[Read before the Auckland Institute, 21st July, 1886.]
On 10th June, 1886, at about 2 a.m., people were aroused by violent noises as of peals of thunder, and volcanic rumblings, and towards the south-west the sky was illumined with strong light, from the midst of which at intervals shot forth balls and forks of fire.
From about 2 till 9 a.m. there was a succession of shocks of earthquake of moderate force, accompanied by a peculiar floating or rolling, as it were, of the earth.
At about 3 a.m., the sky at the time being perfectly clear and starlight, an inky-black cloud rose in the south-west and drifted towards the north-east, and gradually quite overspread the heavens; and a rain of fine ash, and subsequently dust, commenced, which lasted till noon, and covered the Opotiki district to a depth of about 1 ½ inches. The air was unusually cold. It was pitch dark till 10.20 a.m., at which hour the fall became slighter and daylight gradually appeared, and the rest of the day was twilight.
Animals were greatly distressed, and cattle gave vent to constant bellowings. Many small birds died, and insect life suffered severely.
No tidal disturbance was noted.
At Orete Point, 45 miles north-east as the crow flies from Opotiki, Mr. Seccombe describes the morning of the 10th June to have been clear, and at about 8 a.m. the cloud of dust caused darkness, and a layer of ashes and dust was deposited of about the same depth as at Opotiki.
“Opotiki, 22nd June, 1886.
“My Dear Mr. Dumerque,—
“I kept rough notes of what I experienced on the morning of the 10th instant, and give you them with pleasure.
“It was fine bright moonlight up to 10.30 p.m. of the 9th, when I ‘turned in.’ Between 3 and 4 a.m. of the 10th I was aroused by a noise like distant thunder. I took little notice of it for a time; but as it developed it became occasionally a continuous roll, broken at intervals by explosions resembling heavy artillery fire. Cattle were bellowing and horses neighing, and it became quite evident that a storm of unusual character was brewing. This much could be surmised while lying in bed. What appeared to be gentle rain was heard falling on the trees near the window, but it was never heavy; and the thunder seemed to remain in the same spot. The usual sound of the rain running off through the spouting was conspicuous by its absence, and created surprise in my mind. The lightning was bright and the thunder loud, but between the peals at times the noise as of distant artillery-fire was audible. Mild shocks of earthquake were also noticeable about every half-hour. I rose at 4.30 a.m., and went into a room with windows facing South and West, and a cold, damp, sulphurous smell led me instinctively to open the window facing South an inch or two and feel the sill. There could then be no longer any doubt as to what had occurred, as a thin sprinkling of sand could be felt outside. It was intensely dark. I then procured a lantern and made my way into the street, which I found evenly covered with a thin coating of dark and fine sand, which was falling gently; and, while it thundered, the sand seemed to fall faster or thicker.
“There was a strong sulphurous smell outside, and the wind blew cold and in gusts.
“About due South a dull flare-up could be noticed occasionally through the falling sand and dust. This led me to think I was at the wrong side of the house, and that it was the glare from an eruption on White Island; but I soon discovered that nothing was to be seen towards the North.
“At 6 a.m. my aneroid barometer stood at 30.05°, and the thermometer at 50° in the office.
“Roosters all round were crowing vigorously from 6 a.m. till daylight came.
“Having read in a late paper that Ruapehu had been seen smoking, I concluded that either that mountain or Tongariro was in violent eruption. Moreover, the mild earthquake shakes, and the fineness of the sand and dust, showed that the disturbance must be a long way off. These reflections were sufficient to prevent alarm. A peculiarity about some of the earthquakes was that the house seemed to be afloat. I found that a scissors suspended by a nail in the wall gave frequent notice of shakes that would not otherwise have been apparent.
“Up to 9.30 a.m. it was dark as pitch, but shortly after-wards showed signs of clearing, and by 10.30 a.m. there was twilight, which gradually brightened until the place where the sun was could be distinguished. The sand and dust penetrated the house, and covered everything.
“From 10 a.m. there was a calm until 2 p.m., when the wind blew lightly from the south; and there was not much more than twilight all day.
“At 5 p.m. it cleared to the eastward, but a thick bank of fog was visible in the west. The night was calm, and cool, and fine, and slight earthquakes were felt occasionally.
“The storm had rendered the telegraph wires useless, and we had no communication with the outer world for about 24 hours. Very little alarm was felt generally, and there was no panic.
“Careful measurements of the depth of sand and dust show that about 1 ½ inches had fallen in town; but it is reported to be deeper on the table land.
“On the morning of the 11th, which was bright and clear, an immense cloud of steam was seen in the west, and it was rightly guessed that Rotomahana was the seat of the volcanic disturbance.
“The sand is nearly black, and lies under the dust, which is of a light mouse colour, and the layer of the former is twice as thick as that of the latter. This sand is precisely the same article that our forefathers, not so many generations back, used for the purpose of drying letters, when blotting paper was not so good or so common as it is now. And some years ago, when I was an office boy in a mercantile house in Old Broad Street, London, engaged in the Russian trade, several of our correspondents in the interior of Russia dried their letters with the same sort of sand.
“E. P. Dumerque, Opotiki.”