Tsunami alert system urged

The lack of a seismic activity warning system leaves us at risk, the Government has been warned. Dick Ahlstrom reports.

Ireland is vulnerable should a distant earthquake send a tsunami in our direction. We have no modern system for detecting seismological activity, leaving us with no early warning of events that can trigger tsunami.

It is nearly a year since the catastrophe that struck countries ringing the Indian Ocean when a tsunami following an earthquake killed hundreds of thousands and devastated thousands of miles of coastline. One of the great tragedies was that people didn't know what was coming because there was no early warning of the danger.

The Dublin Institute for Advanced Studies (DIAS) recently launched a campaign to encourage State investment in a state-of-the-art seismic monitoring network across Ireland, providing an early warning should something happen closer to home.

"Ireland is the only Western nation without a national seismic network, and the only nation that doesn't have real-time data coming in," says the director of the institute's school of cosmic physics, Prof Alan Jones. "This puts us in a very weak position."

There is a matter of "scientific credibility", he notes, but there is also a real threat posed by tsunamis, which can occur in the north Atlantic. "The reality is there is plenty of evidence on the west coast of Ireland showing that tsunami events have taken place," he says. "We know they happen, we can see them in the record."

One of the more recent events was 250 years ago, on November 1st 1755, when an earthquake devastated Lisbon. It triggered a tsunami that struck our western seaboard, reaching our coastline within four hours and throwing up waves estimated at between eight and 12m.

"When you look at the geological record for the region you see recurrent events every 500 years or so. We are now halfway through that, but they can be sporadic. If a Lisbon equivalent went right now we wouldn't know about it," says Prof Jones. We have no real-time monitoring system to detect it and issue a warning.

Geologists are also watching the Cumbre Vieja volcano in La Palma in the Canary Islands. There are real fears - raised again last January by Britain's chief science adviser Sir David King - that a large chunk of the volcano could collapse into the sea kicking off a mega tsunami. It would reach us in about six hours with waves up to 15m high.

Earthquakes occurring in the Caribbean could cause tsunamis and there is also the risk of underwater landslides, as occurred in 1929 in the Grand Banks off the coast of Canada in the western Atlantic. The tsunami it triggered killed about 26 people. A similar landslide risk exists off our own western seaboard along the edge of our continental shelf, Prof Jones points out.

Tom Blake, experimental officer in the DIAS's geophysics section, wrote to the Minister for State in the Department of Environment, Batt O'Keeffe, in October, expressing the institute's concerns. This correspondence was referred on to the Minister last month and is now being considered.

In it, Blake highlighted the antiquated nature of our existing seismic system. The US installed the initial seismic station on Valentia Island, Co Kerry in 1962 as part of a research project.

The DIAS undertook to install a network in 1978 but this only records seismic data; it can not provide instantaneous data.

One station is run here on behalf of Germany but this can only deliver information within between 20 minutes and four hours, Prof Jones says.

The lack of a network doesn't help our scientific credibility, but there are also financial considerations, he says. "There are economic things here as well. If Ireland wants to project the western seaboard as of interest for oil exploration you need to show how seismically stable you are and we just can't tell them."

There are also insurance considerations should damage be caused by a seismic event. And as Blake pointed out in his letter to Batt O'Keeffe, "contrary to public belief, and to public complacency, Ireland is not aseismic, we do experience earthquakes."

The largest local event recorded on the DIAS's own equipment reached 5.4 on the Richter scale and occurred off the coast of north Wales in July 1984. It caused structural damage to buildings on the east coast of Ireland.

The institute estimates that an investment of €400,000 would buy a five-station network, providing national coverage and delivering instantaneous data. It would record events here and would also detect distant events, whether in Indonesia or other parts of Europe.

Ongoing annual costs of about €75,000 would cover staff and maintenance. Such an investment would open research and information exchange opportunities with our EU neighbours, providing educational benefit to our students but also giving us the early warning system we lack.