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...

Could it be connected to some offshore oil rigs in that region? There doesn't seem to be any islands in that area, but if I'm not mistaken, that part of water is an oil and gas producing region.

I was also wondering where in Oxford Falls the cables land. Oxford Falls is a small suburb north of Sydney and it is ... Inland and high up. There are multiple satellite dishes from Optus, Telstra and others in Oxford Falls on Oxford Falls Rd but then there are the Oxford Falls falls and other suburbs before it reaches the ocean.