On the South Island of New Zealand, the Mahuika Comet impact would have been a dramatic event. Within 50 km of the southern coastline, it would have appeared as a fireball ten times larger than the sun, blown over 90% of the tree cover, and ignited grass and trees (Marcus et al. 2005). However, these effects would have ceased within 100 km of the coast. Steel & Snow (1992) believe that local Maori legends and place names refer to a comet event such as this one. They base their hypothesis on the legend of the “Fires of Tamatea” (or Tamaatea). Local ethnographic evidence is best chronicled in the Southland and Otago regions, centred on the town of Tapanui. Here there appears to be evidence for an airburst that flattened trees in a manner similar to the Tunguska event.
The remains of fallen trees are aligned radially away from the point of explosion out to a distance of 40–80 km. Local Maori legends in the area tell about the falling of the skies, raging winds, and mysterious and massive firestorms from space. Tapanui, itself, translates as ‘the big explosion,’ while Waipahi means ‘the place of the exploding fire’. Place names such as Waitepeka, Kaka Point, and Oweka contain the southern Maori word ka, which means fire. The local Maori also attribute the demise of the Moas, as well as their culture, to an extraterrestrial event. The extinction of the Moa is remembered as Manu Whakatau, ‘the bird felled by strange fire’.
Fires of Tamatea
These interpretations have been criticized by Goff et al. (2003). Specifically, they state that the local place names referring to a cosmogenic fire event requires ‘an in-depth knowledge of the culture and traditions of the Maori people’ and interpretation requires the use of ‘many references with cross-referencing between them . . . as opposed to citing an individual reference’ (Goff et al. 2003). We have since gone back to an original source, The Maori-Polynesian Comparative Dictionary compiled by Tregear (1891). The dictionary is based on over 160 references and traces Maori terms back to their Polynesian sources. It supports some of the interpretations made by Steel and Snow (1992). The dictionary refers to Tamatea as a very ancient person. He was the fifth in descent from Rangi, the Sky. The Fire of Tamatea refers to an older legend related to some volcanic catastrophe or conflagration before the Maori came to New Zealand. Tapanui, which is at the centre of Steel and Snow’s (1992) cosmic firestorm, lies at the edge of the destructive effects of the Mahuika impact. Masse & Masse (2006) describes legends in South America referring to wildfires caused by cosmic airburst events. He also notes that although the fires had a cosmogenic source, few legends mention this fact.
Masse (1995) also points out that some Polynesian place names and the names for legendary heroes or supernatural beings can be broken down into their literal components. In this sense, the place name Tapanui (great or large tapa) may relate to the meaning of tapa, which in the 1891 Maori-Polynesian Comparative Dictionary translates as ‘to split’or ‘to pulverize soil’ (Tregear 1891). Similarly, the word ka appears in this dictionary as meaning ‘to burn, to be lighted, to take fire’, while kaka means ‘red-hot’ (Tregear 1891). Nowhere in Maori or Polynesian sources does it mean ‘fever’ as stated by Goff et al. (2003). Possible age of the recent cosmogenic tsunami event.
Dating the Maori Fires of Tamatea and the Mega Tsunami
It is possible to constrain the age of a regional cosmogenic mega-tsunami event and with it many associated Aboriginal and Maori legends using four separate lines of evidence. First, it is possible to surmise the most likely time of meteorite and comet impacts over the last two thousand years using a combination of Chinese, Japanese, and European records of meteor, comet, and fireball sightings. Figure 3 plots the accumulated record, up to the beginning of the nineteenth century, when scientific observations began in earnest. The meteorite records for China and Japan are based upon Hasegawa (1992), while meteorite records for Europe come from Rasmussen (1991). The Asian meteorite records are the most complete with European sightings accounting for less than ten percent of the record over the last one thousand years. The comet record from Asia is based upon Hasegawa (1992). A quasi-cyclic pattern is evident in the comet sighting records that can be linked to the dominance of the Taurid complex in the inner solar system. This complex formed from the breakdown of a giant comet that entered the inner solar system about 15 000 years ago (Asher & Clube 1993; Asher et al. 1994). Recent times when the Earth crossed the trail of this comet debris occurred during 401–500, 801–900, 1041–1100, 1401–1480, 1641–1680 and 1761–1800.
By far the most active period of the past two thousand years happened between AD 1401 and 1480. Second, twenty-nine radiocarbon dates have been obtained from marine shell found in disturbed Aboriginal middens, deposited in tsunami dump deposits and sand layers, and attached to boulders transported by tsunami along the New South Wales coast (Bryant 2001). Some of these dates were obtained from the Tura Point area where mega-tsunami was first identified as an important coastal process in Australia (Young & Bryant 1992). The radiocarbon ages were converted to calendar ages using the INTCAL98 calibration table for marine samples (Stuiver et al 1998). The dates center on the year AD 1500 +85. These dates can only be stated as the most probable time for the deposition of marine shell by tsunami because the flux of atmospheric radiocarbon production around this time was highly variable leading to age reversals in the marine radiocarbon chronology. Based upon the Australian east coast deposits, it is 95% probable that a cosmogenically induced mega-tsunami event occurred between AD 1200 and 1730. This span also incorporates the age of major New Zealand tsunami deposits (Goff & McFadgen 2002;Nichol et al. 2003). Unfortunately, age reversals and the absence of any cross-correlation with a genealogical record make it impossible to identify up to five regional events in New Zealand in the fifteenth century as hypothesized by Goff & McFadgen (2002) and Goff et al. (2003). A cosmogenic source must be considered given the magnitude of the event on both the east coasts of Australia and New Zealand and the widespread distribution of that evidence throughout the region.
The preference for a major impact during this period is also supported by a radiocarbon date from Stewart Island, New Zealand—the closest large landmass to the Mahuika impact site (Fig. 1c). The southern coast of this island shows massive erosion characteristic of mega-tsunami in the form of ramps, knife-like sluices and flutes cut into granite and orientated towards the impact site (Fig. 4). All of these types of landforms have been linked to mega-tsunami (Bryant & Young 1996; Bryant 2001). An age obtained from pipi (Paphies australis) located about 500 m inland and 30 m above sea level at Mason Bay on the west coast of Stewart Island yielded a corrected age of AD 1301 +36.
Third, circumstantial evidence exists for a major environmental event that disturbed coastal Aboriginal culture within this period. For example, a disturbed midden has been found 30 m above sea level within Sydney Harbour (Attenbrow 1992). This is beyond the run-up of modern storm waves in the harbour. The date of this deposit is 1448 AD. There is also clear evidence that Aborigines switched from collecting large molluscs to fishing about 500–700 years ago (Sullivan 1987). We attribute this response to the fact that any large tsunami would have wiped out shellfish populations along the rocky coast. Aborigines thus switched to fishing to survive. At Bass Point, which is dominated by mega-tsunami erosion and which is a headland conducive to the legend of the ocean falling from the sky, the change occurred around AD 1380 (Bowdler 1976). Finally, middens at various sites along the South Coast of New South Wales indicate that edible mussels originating from more protected tidal inlets began to replace gastropods originating from rock platforms concomitantly with the switch to shell fishhooks (Sullivan 1987). Fourth, it is possible to pin down the approximate age of the Fires of Tamaatea. The cosmic fires reported in Steel & Snow (1992) burnt vegetation across the South Island. There are two sources of organic material for radiocarbon dating this event: buried charcoal (Molley et al. 1963) and carbon derived from peats in swamps and bogs that have been burnt (McGlone & Wilmshurst 1999). This material traditionally has been interpreted as reflecting the time of deforestation due to Maori occupation in New Zealand. However, much of the burnt material comes from uninhabitable high country that was burnt on a vast scale. Figure 3 plots the distribution of dates, that span at least two centuries and terminate at the end of the fifteenth century. This wide range in dates is logical knowing that mature trees, already hundreds of years old, burnt. Goff et al. (2003) criticize this dating, pointing out that it is inaccurate, that there are ambiguous regions in the distribution of the dates, and that they peak before one in the observation of comets and meteorites. Even so, Bryant (2001) never tried to interpret the dates beyond the crucial point ‘that few ages occur after the fifteenth century’ concomitant with the peak in meteorite and comet observations. Even the replotting by Goff et al. (2003) of their corrected dates supports this assertion. The Fires of Tamaatea legend may well have a cosmogenic origin. More importantly, the timing of the fires is also coherent with the dating of mega-tsunami deposits along the adjacent coastline of Australia and New Zealand. These four lines of evidence all indicate that a regional mega-tsunami event that was probably due to a comet impact in the fifteenth century.