Tsuname: it could be crowded on the clock tower

TSUNAMI: We've just had a tsunami alert ? so do you want the good news or the bad news?
Wanganui was never going to be directly caught up in the consequences of a 7.8-magnitude earthquake which struck Tonga last week.
But the way the event was handled in the early stages by overseas media and New Zealand civil defence authorities certainly has wide repercussions, even in areas like Wanganui on the so-called "safe" coast.
In a perverse way, the good news is that an event which draws attention to civil defence and public preparedness without loss of life is a valuable educational opportunity.
The Wanganui District Council certainly wasted no time preparing a newspaper advertisement headed "personal household planning for a tsunami emergency". Its content undoubtedly will have sparked more debate.
The bad news ? and it comes as no surprise ? is that the experts really don't know a lot about the tsunami risk along the Wanganui coast.
Anyone living in Wanganui at the time of Prince Edward's much-publicised attachment to Collegiate School will be aware that the presence of royalty adds great significance to a swarm of earthquakes, except perhaps in the mind of seismologists and cynics.
Tremors off Wanganui are a dime a dozen. On April 30, for instance, a 4.7 earthquake was centred 60 kilometres west of the city. Hardly anyone felt it?. and no suggestion of a tsunami.
Naturally it raises the question of why an earthquake off Chile or Mexico can trigger a tsunami which reaches the New Zealand east coast 12 to 15 hours later while a quake off Wanganui usually goes unnoticed.
Before we settle into complete smugness, though, we should acknowledge a theory that a hefty earthquake in the Pacific will not necessarily exhaust itself by thumping the east coast: it might then go round the top and bottom of the country, hit the west coast (that's us), bounce off and head for Australia and eventually reach South America.
Preposterous? Well, Castlecliff registered a lift in the tide gauge following the Boxing Day tsunami.
According to the latest Wanganui advertisement, in a tsunami emergency we should listen to local radio stations or go at least one kilometre inland or at least 35 metres above sea level.
Emergency manager Max Benseman told the Chronicle these figures are a national standard, recognised by the Ministry of Civil Defence.
On this basis you wouldn't want to linger in Castlecliff or other low-lying parts if the city (assuming, of course, that you gained reliable, timely information from a Wanganui station in the first place).
The top of the hill at Castlecliff's Lundon Park and the Cooks Gardens clocktower aren't quite at 35 metres above sea level.
Mr Benseman, who doesn't claim to know all about tsunamis, says the best plan is to head inland "and not split hairs."
If a substantial tsunami starts a few kilometres off Wanganui it will arrive within a minute or three, judging by the known travelling time for tsunamis which flash across the vast Pacific.
Ministry of Civil Defence brochure: "Tsunami ? if you see one it will be too late."
So the agonising which places like Gisborne went through after the Tonga tsunami alert is pointless in Wanganui's case if the threat begins close to home.