Ka kammala wannan magana: Akwai wani babban tafkin da ake kira Lake na Sama a cikin dutsen da ke saman dutsen. An kafa caldera ta hanyar VEI 7 "Millennium" ko "Tianchi" fashewar 946, wanda ya fashe game da tephra. Wannan shi ne daya daga cikin manyan fashewa da kuma mafi yawan tashin hankali a cikin shekaru 5,000 da suka gabata (tare da fashewar Minoan, fashewar Hatepe na Lake Taupo a kusan AD 180, fashewar
1257 fashewar Dutsen Samalas kusa da Dutsen Rinjani da kuma fashewar Tambora na 1815).