A swarm of earthquakes combined with high winds triggered eruption alarms on Mount Ruapehu ski fields this morning.
The overnight storm meant the Tūroa and Whakapapa ski areas were closed, with high winds and bad weather causing havoc, Mt Ruapehu, Whakapapa & Tūroa Ski Areas said.
Posting on Facebook, Mt Ruapehu, Whakapapa & Tūroa Ski Areas said two things are needed for the Eruption Detection System (EDS) to go off.
"The first is earthquakes – we have a few happening over by Turangi today that are popping into the Ruapehu part of the system," the ski fields wrote.
"The second are strong wind gusts that set off the airwave detectors. For the alarm to sound, the system needs to see earthquakes and airwaves together – like the perfect storm mimicking an eruption."
This morning there were both factors and as a result, EDS alarms have sounded.
The ski fields said the alarms were "false positives", and there is no cause for concern at this time.
People at the fields stayed indoors and out of danger until they received the stand-down message.
Meanwhile, snow started falling on the mountain this morning.