Reporoa Caldera
The Reporoa Caldera is a 10 km by 15 km caldera in New Zealand's Taupo Volcanic Zone. It formed some 230,000 years ago, in a large eruption that deposited approximately 100 km3 of tephra, forming the Kaingaroa Ignimbrite layer. It contains three rhyolitic lava domes and is associated with three geothermal fields. These are the active Reporoa geothermal field in the caldera, The Waiotapu geothermal area north of the caldera rim, and the Broadlands thermal area to the south. The Waikato River runs through the southern half of the caldera.
In April 2005, a large hydrothermal explosion occurred in a cow paddock within the caldera, creating a 50-metre crater. A similar explosion happened in the area in 1948, and smaller explosions have happened in the years between.
