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THE TONGARIRO NATIONAL PARK. 



The Tongariro National Park, one of the five national parks of 

 New Zealand (the others being Mount Egmont, the Waimakariri, 

 Mount Cook, and the Sounds), is the chief one located in the North 

 Island, and includes within its boundaries the great volcanic cones 

 of Ruapehu, Ngauruhoe, and Tongariro. 



Largely owing to the presence of the volcanoes of the Tongariro 

 National Park, New Zealand has a reputation as a volcanic country 

 which is not entirely deserved. True, at various epochs of bygone 

 geological eras there have been districts where volcanic action has 

 been intense, notably in the South Island near Dunedin, at Banks 

 Peninsula, at the eastern base of the Southern Alps, in Marlborough, 

 and in the North Island in the vicinity of Auckland, on Coromandel 

 Peninsula, near the Bay of Islands, and at Egmont ; but the greater 

 part of the land-surface has been formed by the more orderly 

 processes of denudation, sedimentation, and vertical uplift in which 

 paroxysmal action has played a very subordinate part. On the whole, 

 the Tertiary era was the time of greatest volcanic activity, especi- 

 ally in the North Island, and present-day manifestations, interesting 

 though they may be, show a decline in energy which may herald 

 approaching extinction. But periodicity is such a characteristic 

 feature of volcanic action that we cannot predict this for certain, 

 and present decline may be merely the prelude to more intense 

 activity in the near future. If this is to occur, then the value of 

 a volcanic observatory would be very great indeed. 



The only existing active foci in the North Island lie on a line 

 stretching in a north-east direction from Ruapehu towards White 

 Island, in the Bay of Plenty, but several of the points of special 

 interest are located within the actual boundaries of the Park. Its 

 most striking landscape feature is Mount Ruapehu (9,175 ft.), not 

 so graceful or symmetrical as Egmont, but still a noble-looking 

 mountain, undwarfed by any neighbouring height, and rising from 

 a circular base some forty miles in circumference to a summit 

 truncated by a crater nearly a mile across. The appearance of size 

 is increased by the fact that it rises direct from a plateau for close 

 on 6,000 ft. with slopes which are regular and uninterrupted. It is 

 a composite cone, perhaps a twin cone, constructed of flows of lava 

 and interstratified layers of ash and scoria. The summit-crater is 

 almost filled with ice, which has used the hollow as a " collecting- 

 ground," the excess overflowing the low parts of the crater-ring 

 chiefly towards the east, while a part moves in the direction of a small 

 hot lake in the middle of the crater, formed by the action of the 

 escaping steam on the ice, the supply of water being constantly 

 replenished by the melting of the small icebergs which break away 

 from the ice-front as it reaches the hot water. The lake is about 

 400 ft. across, and is depressed considerably below the general level 

 of the ice in the crater. No doubt its conditions vary somewhat 

 with the varying activity of the volcano. Ruapehu has never dis- 

 played within historic times any pronounced activity, though the lake 

 on top is hot and has occasionally discharged mud over the slopes 

 of the mountain. Its scenic interest is increased by the presence of 



