Friday, 8 June 2018

Volcanic Eruption of Mt.Tarawera 10 June 1886

The aftermath, 1886-1948.

4 days after the eruption: “Joe Warbrick and C. Humphreys approached Rotomahana by a side route… as they neared the shore of Lake Tarawera there was heavy deposits of mud, but further inland was dry earth. Until approaching the lake once more, it became so soft; they sunk up to their thighs. Rotomahana was still throwing volumes of mud to the height of hundreds of feet. Te Tarata was invisible for steam…The southern portion of the mountain appeared rent from top to bottom. Flames were still visible. They counted seven active craters on Tarawera Peak and others on Ruawahia” Star, 14th June 1886. p.3 

 #Note: Ruawahia is just one of the domes on Mt. Tarawera, also known as the Tarawera Range. 

1 month after the eruption: “an expedition just returned from Tarawera reports that parts of the terraces are definitely destroyed. Mr Warbrick states that 600ft of made ground has been upheaved and a volcanic pit nearly 1,500 ft. deep has been excavated close to the site of the Terraces.” Thames Advertiser, 10 July 1886.

Mount Tarawera Eruption : Untitled, 20.June 1886, Bay of Plenty, 
by Charles Spencer. Gift of J Hector, 1951. Te Papa (LS.004494)

How the men got their measurements is not told, so one assumes they guessed? An official survey was done soon after the eruption by S. Percy Smith who was the Assistant Surveyor-General. You can read what was said via Papers Past, A.J.H.R online or by reading the bound version in the Don Stafford Room, 2nd Floor of Rotorua Library.

Here are some excerpts from the report :
S. Percy Smith notes some events that occurred in the thermal region some years prior to the eruption. In the Taupo Volcanic Zone as it was then known :

In March 1880 the coasts of the Bay of Plenty were strewn with dead fish of all description, with no sign of disease... the conclusion was that White Island had somehow, perhaps through a subterranean vent, spewed out sulfurous matter into the sea around or near the island.

April 1881 a sudden and unaccountable rise in the waters of the Green Lake.
October 1883 "without warning, the water suddenly rose four feet causing a flood to rush down the Wairoa Stream into Lake Tarawera, whilst at the same time the olive-green colour of the lake took on a muddy appearance"

In 1885 "the crater lake of White Island disappeared leaving a dry bed... it remained so to the present time" also "the hot springs at Mt Edgecumbe and Te Teko became much more active"

S. Percy Smith further quotes Gilbert Mair's observance of the 'Atmospheric influence in the case of Te Tarata, the White Terrace..."The great crater, which is about 90 ft. in diameter is usually full of deep-azure-blue coloured water, occasionally boiling up 10-15 ft. ; but when a keen south wind blows the water recedes and you can descend 30 ft. into the crater, which remains empty until the wind changes..."  Apparently not an uncommon event, Josiah Martin records a similar but more spectacular event on 22 November 1885.

On the 10th March 1886, S. Percy Smith was at Wairakei... "on visiting the geyser known as the Twins, he found it to be throwing up water to some 20 ft. after some years of dormancy.

S. Percy Smith concludes that "the Tarawera eruption appears to offer an example of the first stage in the formation of a volcanic mountain. It is in fact an incomplete effort to form a volcano. Whether the energy has exhausted itself in this effort, and matters will remain in a state of quiescence for long ages until it shall have again gathered strength to advance another stage remains to be seen. 1887.

Also around this time (1885) Mt Ruapehu which had previously been considered dormant by both Maori and European settlers was found by Mr W. Cussen on visiting the crater lake to be hot which meant it was no longer dormant.

We know from NZ history that there was a disastrous lahar flow from the crater lake of Mt Ruapehu on Christmas eve of 1953 at Tangiwai, another shortly after midnight on 22 June 1969, a lahar on Mt Ruapehu destroyed the kiosk at the Whakapapa ski field. Thanks to the lateness of the hour, no skiers were at risk. In 1995 from late August to September Mt Ruapehu erupted sending ash clouds kilometers into the air and debris down the mountain.   Those of us living in Rotorua at the time of the 1996 event will remember the ash cloud that descended on us, turning a bright sunny day into gloom and the gas given off from the ash. affected many residents.  (However the roses in my garden loved the ash and bloomed better than ever before in the summer of 1996.)

This photograph was taken outside the Library
around 10.30 am. on the 17th June 1996.

For those of us who live in Rotorua, Mt Tarawera seems to be dormant, however GNS predicts it will blow again at some point in the future. A report written by I.A. Nairn in 1993 gives a very detailed account of what could happen. 

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