Western Australia's changing coastline over 125,000 years revealed with new mapping

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Archaeologists have combined detailed scientific mapping with technology usually found in big-budget Hollywood films to recreate the history of Western Australia's shifting coastline going back 125,000 years.

Key points: New data shows 125,000 years of WA coastal change in 90 seconds

The animation was created using space and sonar data mapping

It gives a new insight into how humans migrated to Australia

The modelling reflects the amalgamation of a series of data sets gathered using methods as varied as space shuttle scans and underwater sonar mapping.

The numbers were crunched and the software produced a highly detailed three-dimensional model of the modern-day northern WA coastline.

Then dynamic factors, such as sea levels, temperatures and moisture levels, were adjusted to work backwards through time.

It is a similar approach to that used with "green screen" technology employed to create computer-generated backgrounds and other virtual effects commonly seen in blockbuster movies.

The result is a detailed 90-second animation showing the changing sea levels and shorelines of the far north-west of WA and western parts of the Northern Territory.

Each frame represents the passing of 100 years, which is about 1,400 years per second, and portrays how the coastline would have at various times grown, become submerged, dried out, eroded or flourished with greenery.

The project was led by US archaeologist and UWA honorary fellow Thomas Whitely, who said it would be useful to academics and researchers from a wide range of fields.

Dr Whitely said of particular interest for local academics were revelations of points in time where Australia was far closer to its neighbouring countries.

"It's useful for archaeologists to understand timeframes within which people could travel from Indonesia and East Timor into Australia," he said.

"There's a lot of speculation going on about when people would have travelled and what routes they would have taken."

A time when you could see East Timor from Australia

Dr Whitley said the data, represented in the animation, shows Western Australia and East Timor were closest about 18,000 years ago.

"For long periods of time in the distant past, a person in East Timor could have seen either islands themselves, the mainland, or weather effects from those land masses of Australia," he said.

"First human migration would have had to have been by some kind of watercraft, because there was never a land bridge even at maximum glacial depth, but people would have been able to see something on the horizon to paddle towards at numerous periods in the past.

"It helps us as archaeologists learn about what places people may have settled, how they were likely to have survived, whether they were focused on a maritime economy or perhaps had access to inland resources, what climatic conditions they may have been facing, how stable shorelines were for them, where more reliable resources might have been encountered."

Dr Whitley said the research could also reveal islands which were once part of the mainland, and even potential archaeological sites which now lie under the sea.

Similar methods of mapping and modelling can be applied not only to look into the past, but also to provide state-of-the-art predictions of what sea levels and shorelines might look like hundreds and even thousands of years into the future.

Dr Whitley is currently working in San Francisco where similar techniques are being employed to identify infrastructure such as highways, and also archaeological sites, that are vulnerable to sea level rises and tidal activity.

Topics: oceans-and-reefs, climate-change, population-and-demographics, archaeology, earth-sciences, science-and-technology, perth-6000, wa, nt