Civil Defence is advising Hawke's Bay people to be prepared for possible further eruptions and ash fall from Mount Tongariro.
Agencies including Police, Fire, Ambulance, District Health Board, Unison and Civil Defence met on Friday and have agreed to a plan should the current state on Mount Tongariro escalate.
GNS has advised more eruptions are possible, but the impact on Hawke's Bay is likely to be ash fall to a depth of 2-3 millimetres. While this sounds minimal, any amount of ash fall can have an impact, as volcanic ash is toxic.
HBCDEM Group Manager Ian Macdonald says ash fall can aggravate respiratory conditions, getting into the eyes and mouth. It can create discomfort for pets and be poisonous to stock. Volcanic ash is also abrasive and can affect outdoor mechanical and electronic equipment.
"We encourage people to consider how ash fall might affect them and take action now so that they are prepared," says Ian Macdonald.
Volcanologists hope that today they will have a clearer idea of what caused last Monday's Mt Tongariro eruption, and how likely it is to explode again.
Mike Rosenberg, of GNS Science, said many of the pieces of the puzzle - ash and gas samples, analysis of the earthquakes which preceded the eruption and visual descriptions of it - would be brought together today and put before experts.
``I'm hoping that today there will be some consensus and a clear and consistent message about what's caused the eruption and what's likely to happen in the future.''
Farmers and horticulturalists should be familiar with information on the Ministry for Primary Industries website http://www.mpi.govt.nz, MPI's Adverse Event Volcanic Impact document, and consider how ash fall could impact their operations.