That's no island. That point is deep in the interior of South America,
in western Brazil, about 140 miles west of Rondônia.
Kangaroo Island, Australia is at 36 degrees south and 137 degrees east.
There is nothing at 36 degrees south, 138 degrees west. 36 degrees south, 138 degrees east is close to Kangaroo Island, off the coast of Australia.
Adelaide Island
Brazil
Tasmania
Kangaroo Island, Australia is at 36 degrees south and 137 degrees east.
"45 degrees south" is a latitude.
There is nothing at 36 degrees south, 138 degrees west. 36 degrees south, 138 degrees east is close to Kangaroo Island, off the coast of Australia.
Macquarie Island lies close to 54 degrees south.
Middle of the South Pacific, south and west of Pitcairn Island
Saunders Island
Brazilla Brazil
Adelaide Island
Yes. Christchurch is about 43.5° south, and Dunedin is about 45.9° south.
Brazil
Tasmania
no such island