Smart sensing tech to help scientists peer inside volcanoes 27 Dec, 2020 12:02 AM 4 minutes to read GNS Science lifted Mt Ruapehu's Alert Level to two after measuring temperatures of 43C in its Crater Lake, amid other signs of volcanic unrest. Photo / GeoNet GNS Science lifted Mt Ruapehu's Alert Level to two after measuring temperatures of 43C in its Crater Lake, amid other signs of volcanic unrest. Photo / GeoNet Technology first designed for the military could offer a crucial early look at the same volcanic rumblings that just prompted GNS Science to ramp up Mt Ruapehu's warning level. A new study will draw on sophisticated remote-sensing equipment to peer inside volcanoes' hydrothermal systems, which could change over years - or even days.