4 Tongariro, New Zealand (45)
When most people think about the active volcanoes of New Zealand, Ruapehu springs to mind. However, that volcano merely rumbled in 2012. It was its neighbor, Tongariro, that decided to take action with two explosive eruptions from the Te Maari craters during the summer and fall after months of seismic unrest and increased gas emissions. This was the first eruptive activity on the main Tongariro massif since 1896. Neither eruption was long-lived and mainly appeared to be steam-driven events that sent ash over the region near the volcano. However, any time that is new introduction of heat beneath a volcano, you need to watch to see if new magma might be on its way, so 2013 could be more eruptions at Tongariro.
Image: The plume from the November 21, 2012 eruption of Tongariro. Craig Miller/GNS Science.
