TY - JOUR

T1 - Tarawera 1886, New Zealand - A basaltic plinian fissure eruption

AU - Walker, George P.L.

AU - Self, Stephen

AU - Wilson, Lionel

N1 - Funding Information: New Zealand,a nd by one of us (S.S.) during the tenure of a Universityo f Wellington post-doctorafle llowship. L.W. thanks the LeverhulmeT rust Fund for support,a nd the GeologyD epartmenot f AucklandU niversityf or its hospitalityd uringthis study. Thanks also to Mr. L.W. Hickford of Papa-kura for supplyinga sampleo f ash collectedin 1886 from Maketu. Hawaii Instituteo f Geophysiccso ntributionN o. 1351

PY - 1984/6

Y1 - 1984/6

N2 - New Zealand's biggest and most destructive volcanic eruption of historical times was that of Tarawera in 1886. The resulting scoria fall has a dispersal very similar in extent to that of the Vesuvius A.D. 79 pumice fall and is one of the few known examples of a basaltic deposit of plinian type. A new estimate of the volume (2 km3) is significantly greater than previous estimates. The basalt came mainly from a 7-km length of fissure, and emission and exit velocity were fairly uniform along at least 4 km of it, this is one of the few documented examples of a plinian eruption from a fissure vent. Primary welding of the scoria fall resulted where the accumulation rate exceeded about 250 mm min-1. A model of the eruption dynamics is proposed which leads to an estimate of 28 km for the height of the eruption cloud and implies a magma volatile fraction of 1.5-3%. Violent phreatic explosions occurred in the southwestern extension of the fissure across the Rotomahana geothermal field, and it is thought that some of the water responsible for the power of the plinian eruption came from this source, though its amount was not sufficient to turn the eruption into a phreatoplinian one.

AB - New Zealand's biggest and most destructive volcanic eruption of historical times was that of Tarawera in 1886. The resulting scoria fall has a dispersal very similar in extent to that of the Vesuvius A.D. 79 pumice fall and is one of the few known examples of a basaltic deposit of plinian type. A new estimate of the volume (2 km3) is significantly greater than previous estimates. The basalt came mainly from a 7-km length of fissure, and emission and exit velocity were fairly uniform along at least 4 km of it, this is one of the few documented examples of a plinian eruption from a fissure vent. Primary welding of the scoria fall resulted where the accumulation rate exceeded about 250 mm min-1. A model of the eruption dynamics is proposed which leads to an estimate of 28 km for the height of the eruption cloud and implies a magma volatile fraction of 1.5-3%. Violent phreatic explosions occurred in the southwestern extension of the fissure across the Rotomahana geothermal field, and it is thought that some of the water responsible for the power of the plinian eruption came from this source, though its amount was not sufficient to turn the eruption into a phreatoplinian one.

U2 - 10.1016/0377-0273(84)90016-7

DO - 10.1016/0377-0273(84)90016-7

M3 - Journal article

AN - SCOPUS:0021613532

VL - 21

SP - 61

EP - 78

JO - Journal of Volcanology and Geothermal Research

JF - Journal of Volcanology and Geothermal Research

SN - 0377-0273

IS - 1-2

ER -