UNE Publicity Office

Scientists crack the climate and sea level code near a Sydney beach

Sydney beach-goers have been relaxing within metres of evidence that may amount to the most important research findings about sea level and climate change, human history, geography, and meteorology to emerge this year.

By identifying semi-fossilised shellfish and calcareous coated worms in caves and walls surrounding Sydney beaches and then dating them with Carbon-14 dating methods, the University of New England scientists have discovered what they believe to be an accurate record of sea level change over the last 6,000 years. They have also ascertained information about climate, the environment, and water temperature.

Eminent academics, scientists and public officials met at South Cronulla on the edge of Port Hacking, Sydney this morning to view the evidence at a study site used by the researchers, Professor Peter Flood, Dr Robert Baker and Dr Bob Haworth. The researchers have found sites with similar characteristics at Bundeena, Vaucluse, Broken Bay and at Valla Beach on the north coast of NSW.

Professor Flood, Head of UNE's School of Physical Sciences and Engineering, pioneered the research at Valla Beach, while Drs Baker and Haworth of the School of Human and Environmental Studies are the co-authors of two articles soon to be published in the leading international journal of marine tectonic science, Marine Geology. Their work is now gaining international recognition following the emergence of supporting evidence from South Africa, Brazil, Rottnest Island off Western Australia, New Caledonia, and Magnetic Island off Queensland.

Ramifications from the Sydney findings include:

• a challenge to the assumption that sea levels have been stable for the last 6,000 years, evidence that rewrites all previous greenhouse models, and a new way to understand the greenhouse debate;
• evidence that sea levels and climates can change greatly within the span of a lifetime, that they have been changing for centuries before modern-day industrialisation, and with possible dramatic historical consequences;
• a new way to measure and predict sea level trends by monitoring the growth of molluscs and corals next to the shore;
• evidence that the sea level fell one or two metres in less than 100 years, 3,000-3,500 years ago in tandem with the cooling of the climate.
• new theories about the decline of the Egyptian and other middle eastern civilisations (Minoan empires) and the establishment of Israel around 1500 BC, coinciding with the worldwide climatic deterioration indicated by the Sydney sea level fall;
• a new theory that the populating of the Pacific Islands by ocean voyagers who became modern Polynesians was made possible by the sudden exposure of atolls about 3,000 years ago;
• a new climatic record of Australia that improves our understanding of the climate for the last few thousand years;
• a new appreciation of the dramatic change Australia's climate has undergone in relatively recent history with all of the ramifications this will have for Australia's farmers. Prior to 1700 BC, the researchers believe, the Sydney region was subject to a much more tropical climate, and home to tropical molluscs, corals, and other organisms such as dugongs. The fall in sea level would have exposed much of the land that present day Sydney is built on and many low-lying Pacific Islands. Prior to the fall in the sea level, the researchers believe, Botany Bay was probably lapping around the edges of the current site of the Sydney Cricket Ground, while the current Olympic site would have been underwater;
• new theories about Aboriginal history and the geology of Australia's coastline. Many rock shelfs used by fishermen on the east coast of Australia today are believed to be remnants of old coastal semi-submerged shore platforms before the drop in sea level. This finding explains why Aboriginal middens older than 3,000 years cannot be found near to the coastline or in low-lying areas. A proliferation of Aboriginal artworks of around 3,000 years ago has been linked to the stress of geographical and climate change.

Media contact: Gavin Atkins, UNE Publicity (02) 6773 3570 &endash; on December 3, 4 and 5 1999 mobile phone 0417 040 541.

Photographs and other information at: http://smithserver.une.edu.au/photography/sealevels.html

This page is maintained and updated fortnightly by Jo Philp Marketing and Public Affairs,
University of New England, Armidale NSW 2351, Australia, phone (02) 6773 2103
Last updated 2 December 1999