By James Grubel

(Reuters) - A powerful 8.0 magnitude earthquake struck near the Solomon Islands on Wednesday, triggering a small tsunami that swept into isolated island communities and sparked tsunami alerts across the South Pacific that were later canceled.

Damage reports were limited, and there were no reports of casualties.

The quake struck 340 km (211 miles) east of Kira Kira in the Solomons, the Pacific Tsunami Warning Center in Hawaii said.

A tsunami measuring 0.9 metres (three feet) hit remote Temotu province in the Solomons following the quake, the center said, but it later canceled warnings for other South Pacific islands, as well as for Australia and New Zealand, as the danger of a major destructive wave passed.

Luke Taula, a fisheries officer in Lata on Santa Cruz Island, which took the brunt of the tsunami, said it arrived in small tidal surges rather than as one large wave.

"We have small waves come in, then go out again, then come back in. The waves have reached the airport terminal," he told Reuters by telephone.

The worst damage would be to villages on the western side of a point that protects the main township, he said.

"There are no casualties reported so far. But there are reports that some communities have been badly hit, their houses have been damaged by the waves."

About 5,000 people lived in and around the town, but the area was deserted as people fled to higher ground, Taula said, adding that aftershocks were being felt.

HOT SPOT

The Solomons, perched on the geologically active "Pacific Ring of Fire", were hit by a devastating tsunami following an 8.1 magnitude quake in 2007. At least 50 people were killed then and dozens left missing and more than 13 villages destroyed.

"It's an area that is very prone to earthquakes," said Jonathan Bathgate, seismologist at Geoscience Australia. "We've had seven 6-plus magnitude earthquakes in this region since January 31, so it has been very active in the past week."

Initial signs were that the tremor was a thrust quake, in which vertical movement in the continental plates generates higher risk of tsunami, Bathgate added.

Authorities in the Solomons, Fiji, Guam and elsewhere had urged residents to higher ground before the Pacific Tsunami Warning Center canceled its alerts.

"The earthquake would have to be quite a bit bigger to make a much more sizeable tsunami," said Brian Shiro, geophysicist for the center in Hawaii.

"The good news for the folks in the region is that the tsunami appears to be constrained to the areas we've listed in our bulletins and it's not going to be a an oceanwide threat."

(Reporting by James Grubel in CANBERRA,; Additional reporting by Michael Perry and Lincoln Feast in SYDNEY and Alex Dobuzinskis in LOS ANGELES; Editing by Ken Wills)