Cosmogenic Mega-Tsunami in the Australia region – are they supported by Aboriginal and Maori legends?
Abstract: Mega-tsunami have affected much of the coastline of Australia over the past millennium. Such catastrophic waves have left an imprint consisting predominantly of bedrock sculpturing of the rocky coastline and deposition of marine sediments to elevations reaching 130 m above sea level. One of the largest of these events occurred in eastern Australia in the fifteenth century.
This event may be related to the Mahuika impact crater found at 48.38 S, 166.48 E on the continental shelf 250 km south of New Zealand. A comet at least 500 m in diameter formed the crater. Maori and Aboriginal legends allude to significant cosmogenic events in the region, while Aboriginal legends about tsunami are common along the eastern Australian coast. Evidence for legends that could describe the impact of a cosmogenic tsunami also exists in NW Australia. Here geological evidence of a single mega tsunamis recent as in the seventeenth century covers 1500 km of coastline. We term this event Wandjina after the artwork related to the legends. More attention should be given to oral traditions in searching globally for other sites of significant mega-tsunami.
Then the sky moved . . . heaved and billowed and tumbled and tottered. The moon rocked. The stars tumbled and clattered and fell one against the other . . . The great star groups were scattered, and many of them, loosened from their holds, came flashing to the earth. They were heralded by a huge mass, red and glowing, that added to the number of falling stars by bursting with a deafening roar and scattering in a million pieces which were molten . . . Burragorang/Illawarra legend (Peck 1938, p. 202–203)
He had never before seen the sea, and he did not know what it was. He believed it to be a great sky . . . and that the sky had fallen down . . . . It was that a great ancestor had left the earth and had gone up into the sky . . . . He tried to return but the hole that he had made was closed up. Yet he did not give up hope, and by beating upon it he loosened it and it fell. What Makes the Waves (Peck 1938, p. 119)
The Moa disappeared after the coming of Tamaatea who set fire to the land. The fire was not the same as our fire but embers sent by Rongi [the sky] (Hill 1913, p. 331)
These legends—the first two Aboriginal from the coast of New South Wales south of Sydney and the third Maori from New Zealand describe natural events or processes with a cosmic origin not usually invoked as being significant in the modern geological literature. If the large object in the Burragorang legend had struck the ocean, it would have had the potential to generate a regionally devastating tsunami. The impact would also have injected billions of tonnes of water into the atmosphere as superheated vapour that would have fallen subsequently as torrential rain that would have exceeded historical levels and produced catastrophic flooding.
Research along the east coast of Australia since 1989 (Bryant 2001; Bryant & Nott 2001) indicates that a mega-tsunami struck and eroded the shores of Lord Howe Island and the rocky coastline of New South Wales over a distance of 600 km around AD 1500 (Fig. 1a). A comet impact in the region is the most likely cause of such a large and widespread event. The location of a possible impact has recently been discovered (Fig. 1b, c), lying in 300 m depth of water on the continental shelf 250 km south of New Zealand at 48.38 S, 166.48 E (Abbott et al. 2003). The crater is 20 km in diameter and could have been produced by a comet 0.5–1.05 km in size traveling at a speed of 51 km s21 (calculations based on Marcus et al. 2005). When it struck, it would have generated an earthquake with a magnitude of 8.2 on the Richter scale.
The lack of sediment that normally settles over time from the ocean suggests that the crater is less than 1000 years old. The comet has been named Mahuika after the Maori God of fire. Tektites found in sediments to the SE indicate a trajectory for this comet from the NW, across the east coast of Australia (Matzen et al. 2003). If the recent age of the event—which is yet to be confirmed by radiocarbon dating—were correct, Aborigines in Australia and Maori in New Zealand would have observed this comet’s dying moments.
The purpose of the investigation into New Zealand and Australian Mega-Tsunami is two fold: to elaborate on the rich, indigenous oral history of the region to show that a recent cosmogenic mega-tsunami possibly occurred and to use similar types of oral history in the Kimberley region of NW Australia to identify other mega-tsunami in the Australian region.