Revised calendar date for the Taupo eruption derived by ¹⁴C wiggle-matching using a New Zealand kauri ¹⁴C calibration data set

Abstract

Taupo volcano in central North Island, New Zealand, is the most frequently active and productive rhyolite volcano on Earth. Its latest explosive activity about 1800 years ago generated the spectacular Taupo eruption, the most violent eruption known in the world in the last 5000 years. We present here a new accurate and precise eruption date [1] of AD 232 ± 5 (1718 ± 5 cal. BP) [2 date is AD 232 ± 10 years (1718 ± 10 cal. BP)] for the Taupo event. This date was derived by wiggle-matching 25 high-precision 14 C dates from decadal samples of Phyllocladus trichomanoides from the Pureora buried forest near Lake Taupo against the highprecision, first-millennium AD subfossil Agathis australis (kauri) calibration data set constructed by the Waikato Radiocarbon Laboratory. It shows that postulated dates for the eruption estimated previously from Greenland ice-core records (AD 181 ± 2) and putative historical records of unusual atmospheric phenomena in ancient Rome and China (c. AD 186) are both untenable. However, although their conclusion of a zero north-south 14 C offset is erroneous, and their data exhibit a laboratory bias of about 38 years (too young), Sparks et al. (Sparks RJ, Melhuish WH, McKee JWA, Ogden J, Palmer JG and Molloy BPJ (1995) 14 C calibration in the Southern Hemisphere and the date of the last Taupo eruption: evidence from tree-ring sequences. Radiocarbon 37:155-163) correctly utilized the Northern Hemisphere calibration curve of Stuiver and Becker (Stuiver M and Becker B (1993) High-precision decadal calibration of the radiocarbon timescale, AD 1950-6000 BC. Radiocarbon 35: 35-65)to obtain an accurate wiggle-match date for the eruption identical to ours but less precise (AD 232 ± 15). Our results demonstrate that high-agreement levels, indicated by either agreement indices or χ 2 data, obtained from a 14 C wiggle-match do not necessarily mean that age models are accurate. We also show that laboratory bias, if suspected, can be mitigated by applying the reservoir offset function with an appropriate error value (e.g. 0 ± 40 years). Ages for eruptives such as Taupo tephra that are based upon individual 14 C dates should be considered as approximate only, and confined ideally to short-lived material (e.g. seeds, leaves, small branches or the outer rings of larger trees). Keywords14 C wiggle-match dating, chronostratigraphic marker bed, dendrochronology, kauri, late Holocene, New Zealand, non-welded ignimbrite, radiocarbon, Taupo eruption, Taupo tephra, tephrochronometry measurements of tree-ring dated wood from New Zealand: 200 BC-AD 950. Radiocarbon 53 (in press) Houghton BF, Carey RJ, Cashman KV, Wilson CJN, Hobden BJ and Hammer JE (2010) Diverse patterns of ascent, degassing, and eruption of rhyolite magma during the1.8 ka Taupo eruption, New Zealand: evidence from clast vesicularity.

A new bipolar ice core record of volcanism from WAIS Divide and NEEM and implications for climate forcing of the last 2000 years

“…Alternatively, a global tsunami probably caused by the violent eruption of Taupo was tentatively dated to c. 200 CE to bypass the obvious age offset to the younger, tree ring derived ages [Lowe and de Lange, 2000]. Recently, the radiocarbon-based age was confirmed by wiggle matching 25 high-precision 14 C dates of buried trees against a regional radiocarbon calibration data set [Hogg, Lowe, Palmer, Boswijk, and Ramsey, 2012]. The revised date for the violent Taupo eruption is thereafter 232 AE 5.…”

Biological flora of New Zealand 13.Pittosporum cornifolium, tāwhiri karo, cornel-leaved pittosporum

“…The environment is suitable south of the Wairoa lowlands in the Wairarapa but there are no current records, probably because nearly all lowland forest in the area has been cleared (Nicholls 1980). Similarly, much of the Taupo Volcanic Zone is favourable in terms of the predicted environmental distribution of P. cornifolium, but observed absences are likely to be due to the ecological impact caused by the 232 AD (Hogg et al 2011) Taupo eruption. Both Mahia in the North Island and Banks Peninsula in the South Island are also environmentally favourable locations where P. cornifolium has not been recorded.…”

Challenges and Benefits of Standardising Early Warning Systems: A Case Study of New Zealand’s Volcanic Alert Level System

“…The caldera volcanoes have a large range in past eruption magnitudes. For example, the TVZ's most-recent caldera collapse took place at Taupo Volcanic Centre (TVC) in 232 ± 5 AD, erupting 35 km 3 of magma (Wilson 1993;Davy and Caldwell 1998;Self 2006;Hogg et al 2012). This devastated a significant portion of the central North Island in widespread pyroclastic density currents (Wilson and Walker 1985).…”