Scientists said they noticed increased seismic activity below Mount Tongariro for weeks but got no specific warning before the volcano blew late Monday night. The eruption of ash and rocks lasted about 30 minutes and didn’t cause any injuries or damage in the sparsely populated central North Island region, which is a designated national park.
The park is a popular tourist destination and formed the backdrop for many scenes in the “Lord of the Rings” movies.
The eruption did prompt some nearby residents to evacuate their homes as a precautionary measure, and caused authorities to temporarily close roads. National carrier Air New Zealand canceled or delayed domestic flights to towns near the mountain. No international flights were affected.
Police said a witness described flashes and explosions followed by a cloud of ash coming from a hole in the north face of the mountain.
Steve Sherburn, a volcanologist at the government agency GNS Science, said the eruption spread a layer of ash several centimeters (one or two inches) thick for several kilometers (miles). He said he’d heard reports of ash traveling on wind currents to coastal towns 100 kilometers (60 miles) away. He said the eruption was likely caused by steam pressure building within the mountain before bursting through the ground.
New Zealand is part of the Pacific’s “Ring of Fire” and has frequent geothermal and seismic activity. However, the last verified eruption of Mount Tongariro occurred in 1897, marking the end of a decade of volcanic activity.
Sherburn said it was too early to determine whether the latest eruption was the start of a renewed cycle of activity.