Ash on the slopes of Tongariro from the August 6, 2012 explosion. Image courtesy of GNS Science and OneNews. The first eruption at Tongariro in 115 years decided to occur in the middle of the night, but as day broke in New Zealand, we have new details of the eruption from the Te Mari crater. GNS Science released multiple reports on the events of the night of August 6, 2012 - along with a highly informative and easy to understand press conference. In brief, here is what we know about the eruption: