Power cuts prompt civil defence rethink over disaster warnings

The power cuts in Auckland have convinced civil defence chiefs they need a variety of ways to warn citizens of tsunami, cyclones and other disasters.

Fixed sirens and warnings broadcast on radio and television figure in local arrangements to raise the alarm among coastal residents. But they can depend on the electricity supply.

"As we found out yesterday, things can go wrong with anything," Auckland's civil defence emergency manager Jim Stephens said yesterday.

Since last month's tsunami alert after the Tongan earthquake, emergency managers have considered the need for electronic measures as part of warning measures.

One prospect, said Mr Stephens, was cell broadcasting, where people living in vulnerable suburbs could be quickly notified by a detailed text message.

The Auckland emergency management group had commissioned a report by Geological and Nuclear Sciences on various future warnings. Mr Stephens said the report recommendations would be discussed with Civil Defence Ministry officials soon.

Auckland group chairman Neil Morrison said a combination of methods was favoured.

With ample notice from the Pacific Tsunami Warning Centre, police and fire service officers could begin evacuation with vehicle sirens and loud hailers.

But if a tsunami was triggered locally because of an earthquake or landslide there would be less time for warnings.

"You could warn people en masse on cellphones but cellphones need to be turned on," he said. "At 3am you could have trouble waking people up."

The GNS Science reports says cell broadcasting has not been internationally tested and does not work with all consumer cellphones.

But it invites "brainstorming" on developing the potential of this option among representatives of the ministry, national groups and communications providers.

Another tsunami warning device for the future - a portable siren-based system with the ability to broadcast a message - is being considered in Waitakere, North Shore and Rodney.

Waitakere City emergency manager Bill Morley said pre-recorded broadcast messages from the box-like units could be remotely activated by cellphone.