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Why dating the most recent major eruption of Long Island, Papua New Guinea, is important

Event Type: 
Event Date: 
16 Jun 2017
EOS Seminar Room - N2-01B-28
Russell Blong
About the speaker: 

Emeritus Professor Russell Blong founded and directed Risk Frontiers (formerly the Natural Hazards Research Centre) at Macquarie University in Australia. After more than 30 years at Macquarie University, Russell ‘retired’ and now works with Aon Benfield Analytics advising the reinsurance broker on natural hazards and issues facing catastrophe loss modelling. Russell holds Masters degrees in Geography (Auckland) and Engineering Science (UNSW) and a PhD in Geomorphology (Sydney). He has researched a wide range of natural hazards and their consequences but his passions include volcanic, earthquake, flood and landslide hazards and their consequences in Australia and the Asia-Pacific. He has published ten books and edited volumes, and more than 200 research papers. He is the Past-President of the International Society for the Prevention and Mitigation of Natural Hazards (the Natural Hazards Society).

About the event: 

A 5 cm thick layer of sediment was first recognised as volcanic ash in the Kuk archaeological site (now a UNESCO World Heritage area) in the central highlands of PNG in 1971. By the early 1980s this tephra had been mapped across an area of more than 80,000 km2, traced back to its source on Long Island, linked to the pyroclastic density current Matapun Beds on the island and recognised as a VEI 6 eruption, one of only 10 or so globally in the last 600 years.

Dating this eruption accurately has been important because of its archaeological significance, its role in elucidating erosional and vegetational histories, its prominence in the development of the c.r.s model of 210Pb concentrations in lake sediments, and in Jared Diamond’s supertramp theory, in measuring the magnitude of the reservoir effect in Lake Kutubu, in determining the antiquity of the widespread time of darkness legends across the highlands, and in providing a minimum age for the disappearance of Yomba, a possibly mythical volcano in the Bismarck Sea. 

This presentation reviews the eruption’s significance, analyses the role of the English navigator William Dampier (who named Long Island in 1700) in deciding whether the eruption occurred in the 17th or 18th centuries, summarises existing ‘dates’ for the eruption which span almost three centuries, and reports the results of a new radiocarbon dating program that pins the eruption down to a decade or so.