Kammala jumlar da ke gaba: Segara Anak wani tafkin rami ne a cikin caldera wanda ya samo asali a lokacin
fashewar dutsen mai aman wuta na Dutsen Samalas a 1257. Caldera yana kusa da Dutsen Rinjani a Tsibirin Lombok a Indonesia. "Segara Anak" na nufin "ɗan teku" kuma yana nufin kamanin tafkin shudi da teku. Dutsen mai aman wuta na Gunung Barujari yana a ƙarshen gabashin tafkin kuma yana da alhakin siffar crescent. Zafin jiki na tafkin shine, wanda ya kai 5-7 ° C (9-13 ° F) fiye da yadda aka saba don tafkin a tsawo. Magma mai zafi a ƙarƙashin tafkin yana da alhakin wannan rashin daidaituwa. Bubbles na gas sun tsere daga kasan tafkin, suna taimakawa tafkin ya sami pH na 7-8.