Tsunami advance warning

Developments

Tsunami advance warning and preparation is very necessary

By Arthur Mccutchan

IF a tsunami were to hit Fiji, people would have as much as 18 hours or as little as five minutes.

If it was caused by an earthquake in Chile, the people of Fiji would be lucky, but if it was caused by an earthquake 30 kilometres away, they’d most likely be run down by a wall of unhardened con crete-like slush within five minutes.

“We have those two extremes,” South Pacific Applied Geoscience Commission programme director Russell Howarth said. “We know we will have enough warning if the tsunami is generated in South America and we know we may not, if it is generated just off our coast line. But imagine if one were to be gen erated two hours away, near Tonga, Vanuatu, or New Caledonia. How would we respond to that?”

The tsunami monitoring centre in Hawaii already keeps an eye out for those really big events that cause tsunamis that travel right around the world. And it wouldn’t be practical for Fiji to set up a system to monitor local tsunamis because the damage would be done even before people were warned.

Discussion then has focused on a

regional early warning system, for those

tsunamis that would take two hours to swamp a country’s coast-line.

“The question we need to ask our selves is whether such a system would work,” Mr Howarth said.

Within that two-hour window, Vanuatu would have to recognise there has been an earthquake, then it would have to notify Fiji that a tsunami is on its way. Authorities in Fiji would have to get on the horn and tell people living in coastal areas to clear off.

“We’d be pushing it if we were to do all that within two hours. The other real worry, of course, is how people will respond. Such is our nature, that we do

not seem to respect what a tsunami can do. They are not like cyclones”.

Cyclones happen all the time so peo ple are constantly reminded year-in, year-out of the destruction they can cause.

Tsunamis don’t happen as often. So people, with their short memories, tend not to remember tsunami destruction even though the damage that a single col umn of water is capable of, in terms of human lives, is thousands of times greater than that from a mass of moving air.

Tsunamis don’t

happen as often. So

people, with their

short memories, tend

not to remember

tsunami destruction

even though the

damage that a single

column of water is

capable of, in terms of

human lives, is

thousands of times

greater than that

from a mass of

moving air.

Honestly speaking, how many of us still think about the Aitape disaster in Papua New Guinea?

There is also the “cry wolf’ syn drome. If authorities give out tsunami warnings and each time no visible tsuna mi hits, people will get sick of running inland. The next time they probably won’t bother. These factors limit the capability of a warning system even if everything else ran well.

“To me, the best solution is to con stantly remind people’s conscience. It’s a

social community problem because geo logically we know what can happen. But we can’t predict what people will do,”

Mr Howarth says.

Since early warning systems probably won’t work very well for locally generat ed tsunamis, the only option would be to prepare people ahead of time.

SOPAC has a database that can pro vide all sorts of information on disaster risk. In the Aitape disaster area for exam ple, the commission’s database can tell you that the three villages there were low lying, that the sea bed slopes away too much to allow reefs to grow, that this slope is prone to landslides and that the whole area lies near a fault in the earth’s crust and is very unstable.

Translated, it means the villages are easily flooded, they lack the buffer that reefs would have provided, and they are at a higher tsunami risk.

Indeed, since records began, nearly every generation along that northern part of Papua New guinea has had at least one bad memory of tsunami devastation, SOPAC coastal Engineering Geologist Graham Shorten said.

There is similar information available for the major financial centres of the region. For Fiji’s capital, Suva, you can , get information about the structure of 'Jt the soil beneath the Reserve Bank, how the building would behave in an earthquake and how much it would cost if the whole thing collapsed into a heap of rubble.

The exact location of all buildings in Suva have been mapped out using 1 global positioning E satellites (GPS).

“It is a lot of work SBBSBBBBI and very expensive but the idea is to get everything on to this database which can then be used by city planners. Since it’s not really practical to have warning systems for local tsunamis, this database will help you plan in the event that one occurs.

For cities there’s so much there in terms of infrastructure, buildings, telecommunications. You can query how each will be affected in any disaster,” Mr Shorten said. Using this information, Fiji can build itself out of the reach of most tsunamis. ■