As a nation that has a strong connection to the ocean, we actually don’t know all that much about its structure. In particular, there are big gaps in our understanding about the intertidal zone – the area between low and high tide on a beach. We have more than 15,000 square kilometres of intertidal zone in Australia, covering our approximately 34,000 kilometres of coastline. Bound by the regular rhythm of the tides, the intertidal zone is a critical area for animal habitats. It also helps us to understand and prevent flooding and coastal erosion.

Research by Geoscience Australia this year led to the first continental-scale dataset of intertidal elevation, essentially forming a three-dimensional map of the Australian coastline. The National Intertidal Digital Elevation Model (NIDEM) took 30 years of satellite images of the Australian coast and processed them using NCI’s supercomputer and cloud systems to find the exact location of the shoreline across a range of tide heights.

Lead researcher Dr Robbi Bishop-Taylor said: “It has been fascinating to see how an incredibly simple environmental process like the rise and fall of the tide can be analysed using big data and supercomputing to reveal something fundamental about the world: the physical shape of our coastline.”

Prototyping through NCI’s Virtual Desktop Infrastructure allowed the research team to rapidly develop and test the models, while running on the Raijin supercomputer allowed them to efficiently process more than 2.5 terabytes of satellite data covering Australia’s immense intertidal zone. The data is now stored at NCI and is easily accessible by coastal researchers and land managers through National Map.

This model is another element in the mapping resource developed by Geoscience Australia for the national research community. Geoscience Australia anticipates that the new continental-scale data will be used to map the habitats of threatened coastal species, identify areas of coastal erosion, plan for extreme events such as storm surges and flooding, and improve models of how sea level rise will affect the Australian coastline.

This research highlight was originally published in the 2018-2019 NCI Annual Report.