Australia, stripped back


New algorithm offers a more accurate picture of the Earth’s top layer.


Mineral map derived from the barest earth. 

Dr Dale Roberts et al.

Modern technology shows Australia at its least vegetated, which researchers hope will provide clues for better managing it under a changing climate.

It reveals the true nature of the soil, says Dale Roberts from the Australian National University, and when combined with other data sets could also show what minerals are there.

The research, which is published in the journal Nature Communications, was a two-stage process.

First, Roberts designed an algorithm that accurately estimates the Earth’s reflected light at every location from satellite imagery, providing a better understanding of the composition of its top layer.

Then he worked with John Wilford from Geoscience Australia to apply the algorithm across the whole continent. The results are freely available here.

“In addition to the enormous scale of the data, the challenge with estimating this from satellite images is they can be masked by clouds or vegetation, or atmospheric conditions that change over time,” Roberts says.

“So we came up with an algorithm to work around all of that. For example, when we have bushfires, they can leave burn scars, which show up as dark patches that can linger up to decades. We’re now able to remove those patches, using our massive archive of imagery.”

The method also has applications in understanding where land has been cleared, how farming practices may have modified soil properties over time, or how climate may be changing our landscape.

Explore #soil #geoscience
  1. https://www.nature.com/articles/s41467-019-13276-1
  2. http://nationalmap.gov.au/
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