calderaa large volcanic crater formed by the collapse of land following an eruptionYellowstone sits atop a massive caldera formed by a super-eruption approximately 640,000 years ago.NoteYellowstone sits atop a massive caldera formed by a super-eruption approximately 640,000 years ago.Elon.io is an online learning platformWe have an entire course teaching TOEFL Academic Vocabulary grammar and vocabulary.Start learning TOEFL Academic Vocabulary now