Paleohydrology and Sedimentology of a Post–1.8 Ka Breakout Flood from Intracaldera Lake Taupo, North Island, New Zealand
Paleohydrology and sedimentology of a post–1.8 ka breakout flood from intracaldera Lake Taupo, North Island, New Zealand V. Manville* Geology Department, University of Otago, P.O. Box 56, Dunedin, New Zealand, and Wairakei Research Centre, Institute of Geological and Nuclear Sciences, Private Bag 2000, Taupo, New Zealand J. D. L. White Geology Department, University of Otago, P.O. Box 56, Dunedin, New Zealand B. F. Houghton Wairakei Research Centre, Institute of Geological and Nuclear Sciences, C. J. N. Wilson } Private Bag 2000, Taupo, New Zealand ABSTRACT INTRODUCTION The Taupo Volcanic Zone, in the central North Island of New Zealand, includes a high concen- Sudden releases of impounded water from Failures of natural or artificial dams have tration of calderas and composite cones, and lakes in volcanic regions constitute a major caused many of the largest known floods, and abundant volcanic lakes vulnerable to breakout and frequently repeated hazard. An outburst constitute a significant threat to life and property floods (Healy, 1975). We present evidence for the flood from Taupo caldera, New Zealand, (Costa, 1988; Costa and Schuster, 1988). Out- catastrophic release of ~20 km3 of water from the released ~20 km3 of water, within decades burst events have occurred in a variety of envi- Taupo caldera following blockage of the caldera- following an ignimbrite-emplacing eruption, ronments and settings, including the enormous lake outlet during the Taupo 1.8 ka eruption ca. 1.8 ka. Paleohydrologic reconstruction of Pleistocene outbursts from glacial and pluvial (Wilson and Walker, 1985). We reconstruct the the Taupo flood provides estimates of peak dis- lakes in North America (e.g., Baker, 1973; Baker paleohydraulic parameters associated with this charge at the outlet in the range 17 000–35 000 and Bunker, 1985; Lord and Kehew, 1987) and flood using dimensionless and physical models m3/s.
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