FOUR significant waves from Japan's tsunami event on March 11 travelled across the Pacific and were felt in Tonga where fluctuating sea levels up to 1.2m were recorded for several hours after a first wave hit Nuku'alofa's tidal gauge at 5:30 am on Saturday.

The Director of Meteorology, 'Ofa Fa'anunu in a Tonga Tsunami Report of 11-12 March, 2011, said that after the first wave the Sea Level Monitoring Gauge at the Queen Salote Wharf recorded a series of waves and troughs. "The highest waves being the third and fourth waves with wave heights of about 1.2 meters and amplitude (half the wave height) of about 60cm or about 2 feet."

There was no major damage recorded in Tonga.

A 8.9 magnitude earthquake that occurred in northeast Japan at 0546UTC (or 6:46 pm Tonga time) set in motion a Pacific Wide tsunami wave, which saw warnings issued for the entire Pacific Basin, including Tonga.

'Ofa said the first tsunami warning for Tonga was issued from Fua'amotu at 9:15pm on Friday with a National Broadcast from the National Forecasting Centre.

Following that the Meteorological Service issued a total of 14 tsunami warnings for Tonga on one hour intervals advising people living along the coast to move inland and to higher ground.

"As the wave got closer to Tonga the Geology Unit moved to Fua'amotu at 4:00am local time where all warning operations continued . . . until the warnings were cancelled at 9:45am on Saturday March 12 when waves measured at the tide gauge at Nuku'alofa started to ease," he said.

Tsunami wave height maps were issued by the West Coast and Alaska Tsunami Warning Centre afte the tsunami.