volcano rano kau/ rano kao, the largest volcano crater in rapa nui easter island

basalt basaltic body caldeira cliffs climate cone crater diameter easter endemic environment eroded erosion eruption explosion extinct flow freshwater hanga igneous inner isla island kao kari lake lava materials micro national native natural nui obiian orongo park pascua pumice pyroclastic rainwater rano ranu rapa rapanui reeds reintroduced relict roa rocks sea sediments slope steep stone stored toromiro totora trachyte tree violent vocanic volcano water workers