Tsunami Warning

Mana (Auckland), Volume 2, Issue 1, 6 April 1978, Page 7

Tsunami Warning

A regional tsunami warning centre will be established at the Apia observatory this year.

Cabinet approved the establishment of the centre which will link Western Samoa into an international warning system. A tsunami is a wave which is produced by an earthquake.

A background paper presented to Cabinet said an earthquake last year caused a small tsunami. This was the Tongan earthquake, which with a magnitude of 7.2 on the Richter Scale, occurred on June 22.

“This tsunami came through the Pacific undetected and no general tsunami alert warping was issued. Had this been a large tsunami, disastrous ramifications would have occurred. This would have affected Niue, Fiji and Western Samoa,” the report said.

The tsunami (black line) radiated out from the epicentre

of the Tongan earthquake

in June last year. The problem of lack of tsunami warning was made clear in the report presented to cabinet. It stated that as Suva was receiving the initial earthquake reports, the tsunami had already struck Lau. As the tsunami was moving through the water at about 480 kilometres an

hour it would have covered the 450 kilometres from Lau to Suva just inside an hour.

The tsunami covered the distance from the epicentre, 1200 kilometres, to Apia in two hours 28 minutes.

For Fiji, Tonga, Niue and Western Samoa it was pure good fortune that it was so small.