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Warning sirens, better communication needed

NUKUALOFA, Tonga (Matangi Tonga, July 7, 2011) – Tonga remains unprepared for a local tsunami and Nuku'alofa is particularly at risk, Tonga's Director of Meteorology 'Ofa Fa'anunu warned today after this morning's tsunami alert, saying that better community alert systems need to be urgently put in place.

Alert sirens are urgently needed as part of a better communication system and alert infrastructure, he said.

"Although warnings are being received and delivered on time to and from warning centres, mechanisms and infrastructure available to raise an immediate alert and response does NOT exist," he warned in a report today on Tonga's response to the 7 July Earthquake and Tsunami in the Kermadec Islands region between Tonga and New Zealand.

He said that most of Tonga's population is located in the capital on a narrow peninsula surrounded by water, where an earthquake nearby could create a tsunami in a matter of minutes to an hour "such as that that caused loss of life in Niuatoputapu in 2009."

The report reveals that in addition to local alert problems only four out of the seven modes of international communications for receiving tsunami bulletins are currently working in Tonga. Tonga Met has configuration problems with the other three satellite and computer early warning systems, including the EMWIN, and NOAA's CHATTY Beetle and CISN.

And it was discovered that Tonga's only tsunami gauge run by the Australian Sea Level Monitoring Network at the Queen Salote Wharf was out of order when critical information was needed this morning.

"If a wave had hit Nuku'alofa we would have been unable to warn Ha'apai and Vava'u of its height," said 'Ofa who monitors the sea gauge online after tsunami bulletins are issued. "We had not been informed that it was out of action, and I will lodge a complaint to Australia," he said.

"Tongatapu, Ha'apai and Niuatoputapu groups are at most risk due to the low lying nature of the land."

This morning three tsunami bulletins were issued by the Pacific Tsunami Warning Center in Hawaii and received in Tonga by email and fax, following a 7.8 magnitude earthquake located in the Kermadec Islands region 930km south of Tongatapu at 8:03 am. The Fua'amotu Weather Centre then issued vebal alerts by telephone to the seven response centres and also through Radio Tonga One announcements.

The first bulletin at 8:12 am local time indicated that the estimated time of arrival would be 9:17 am if a wave had been generated.

The second bulletin issued at 8:33am local time reported waves measured 2.2ft amplitude at Raoul Island tide gauges, 211km west of the earthquake epicenter.

The third and final bulletin issued at 8:59am local time cancelled the warnings but also reported waves measured 3.3ft amplitude at Raoul Island gauges.

A 10cm tidal reading was later recorded at the Suva gauge at around 10:40am.

There were no effects reported to the Tonga Meteorological Service although schools and some businesses were closed for the day once the tsunami warnings were issued.

'Ofa said three main problems encountered locally during the warnings included: phone line congestion, not being able to reach key persons and the AM radio procedures.

A flood of incoming calls to the Tonga Met Office congested the lines making it difficult for the office to contact response agencies. "A direct hotline should be implemented between Met Office, the National Emergency Management Office and the Tonga Broadcasting Commission," said 'Ofa.

All the mobile contacts of TBC listed with the Met Service were not working, engaged or not answered. This caused some delays in initially informing the station to broadcast the warnings. This was also the case with the Tonga Communications Corporation."He also called for changes to AM Radio procedures.

"It is the view of the Warning Centre that TBC procedures for local tsunami warnings should be revised. During warnings events for a local tsunami, the TBC AM Radio should consider not broadcasting anything else such as Tonga news from overseas or funeral advices or anything else but repeat the warnings over and over and standby for live interviews with the warnings centre, seeing that local tsunami waves can affect the shoreline within minutes," he said.

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