106 J. D. Dana — Explosive Eruptions. 



The accompanying map and explanations will make the remark- 

 able Tarawera events more intelligible.* It represents the Tara- 

 wera geyser region, its lakes, mountains, and other features. A 

 small ma]) to the left shows the northern New Zealand island, 

 and the site of Tarawera in the X. 35° E. volcanic line of Rua- 

 pehu, Lake Taupo and White Island; and White Island is repre- 

 sented in its usual steaming condition in a sketch just above. 

 The line of the eruption in 1886 extended in a N.E.-S.W. course 

 from Lake Okaro through Mt. Tarawera and Mt. Wahanga. 

 Lake Rotomahana at the time of the eruption was emptied and 

 converted into a region of craters. This lake, previous to the 

 eruption, had on either side, a geyser basin and one of the famous 

 geyserite terraces of New Zealand; the "Pink terrace" on the 

 west (PTon the map), and the larger and more beautiful " Whit£ 

 terrace " (WT) on the northeast side with the geyser Te Tarata 

 at its head. The outflowing waters of Te Tarata, descending 

 the gently sloping surface to the lake, had covered an area 

 eleven and a half acres in extent with its siliceous (or geyserite) 

 depositions, forming a descending succession of whitish cream- 

 colored and almost porcelain-like terraces. A view of a portion 

 of the terrace is given in the left upper corner of the map. Both 

 terraces were buried in volcanic mud and ashes, a mud volcano 

 displacing the geyser basin. A sketch to the left represents 

 (from a photograph by Mr. C. Spencer), the region of the " great 

 chasm," 200 yards and more wide, made in the Tarawera range at 

 the outbreak; and the map gives its position, and also the positions 

 of the several centers of eruption along the region. The outer 

 dotted line on the map encloses the part of the Tarawera region 

 that was covered with volcanic ashes, mud and scoria, and the 

 inner, the portion of the larger area that was buried beneath mud ; 

 and the latter includes the buried villages of Te Ariki, Moura and 

 Wairoa, where there was destruction of life, as well as a general 

 obliteration of houses. Subsidences continued to take place along 

 the great opened fissures for weeks after the eruption had ceased. 



At Krakatoa, in 1883, the projectile discharge was equally 

 sudden, and far more terrible and destructive. The height to 

 which the dust was carried was made by Professor Verbeck 

 50,000 feet. It began in the early morning of one day, made 

 clay into night (by its ejections of ashes) for 36 hours, and left 

 the sky clear by the close of the next day. Nothing is said of 

 an outflow of lavas. 



The earthquakes at Tarawera were not violent ; they were 

 felt to a distance of 50 or 60 miles only ; and a dozen miles 

 from Tarawera Mountain, at Rotorua, on the geyser plains, no 

 shock was able to upset a chimney or jar down crockery from 



* The facts here given are from au account of the eruption by T. W. Leys, 56 

 pp. 8vo. with maps and other illustrations, Auckland. New Zealand, aud the 

 Report of S. Percy Smith, Assistant Surveyor General, 84 pp. 8vo. Wellington. 

 The height of the ejections above given is cited from the latter work, page 29. 



