Ko e tuʻahivi fakamoʻungaafi ʻo Tonga ko e ʻotu fonua moʻunga vela ia, ʻoku ʻāluloa mei ʻAta ʻi he tongatongahihifo ki Tafahi ʻi he tokelautokelauhahake. ʻOku ne huʻufataha mo e Kelimoana ʻo Tonga, ʻi he mamaʻo ʻo e kilomita ʻe 200 pe ofi ki ai. ʻOku ui foki ko e Ngaope Tofua (Tofua volcanic arc).