how taupo caldera formed
Lake Taupo fills a topographically indistinct, roughly 35-km-wide caldera that is the site of the most prolific rhyolitic volcano of the Taupo volcanic zone. The caldera was formed during two major explosive eruptions, the Oruanui eruption, roughly 22,600 years ago, and the Taupo eruption, about 1800 years ago.