Mining [1] worth $160+ billion per year. There are mammoth automated iron ore mines in that area [2], with railways to Port Hedland [3]. No doubt their communications links follow the railway alignment to Port Hedland, then join the undersea cable to Darwin, then back to head office.

The extra loop heading north is probably the Greater Sunrise gas fields.

[1]https://www.vocus.com.au/why-vocus/our-network-and-expertise...

[2] https://im-mining.com/2019/08/06/pilbara-leads-way-haul-truc...

[3] https://en.wikipedia.org/wiki/Port_Hedland,_Western_Australi...

[4] https://www.woodside.com.au/what-we-do/international-develop...