KEY POINTS:
Mt Ruapehu is showing signs it could erupt without warning, prompting a warning to climbers of the volcano's heightened risk.
Readings from the lake have shown a heightened magma input, and readings from the air above the lake showed an increase in released volcanic gas.
Department of Conservation scientist Dr Harry Keys told the Weekend Herald yesterday several months of volcanic information had lead scientists to say "hang on, something unusual is happening".
