In Solomon Islands, emergency crews are on their way to the remote Santa Cruz islands after a tsunami caused serious damage to at least five villages.
The one metre high tsunami was triggered by a 8.0 magnitude earthquake and travelled half a kilometre inland.
The Disaster Management Office in the Solomon Islands says nine people have died and two are missing.
World Vision estimates that 700 houses have been damaged or destroyed with as many as 3500 people affected.
Damage to the airstrip at Lata means flights carrying emergency and relief workers to the Santa Cruz Islands have been delayed.
The Solomons National Disaster Management Office says an aircraft from the Royal Australian Air Force has been deployed to provide an aerial survey of the damage.
Work is underway to repair the strip, and once it's been passed by civil aviation officials a decision will be made on when flights will depart from Honiara.
A patrol boat is also scheduled to leave for the province, carrying emergency supplies.
World Vision says the full extent of the damage is yet to be assessed with debris and high water levels cutting off access to some areas.
Solomon Islands director, Andrew Catford, says the immediate health concern is the spread of disease.
"There's quite a bit of livestock, chicken and pigs and fish are sort of strewn, particularly in these five communities," he said.
"So obviously you don't want to leave that there for too long given health issues so that's one of the immediate tasks this morning to clear that up."
Solomon Islands police spokesman Godfrey Abia says it is still unclear how many people may have been affected.
"Some of the villages close to the coastal area have been totally wiped out by the waves and it travelled further inland, some 500 metres," he said.
"Those communities and those places are very remote. We cannot really confirm how many people live in any of those villages."
Map: Quake off Solomon Islands
The quake struck near the Santa Cruz islands, about 300 kilometres east of the Solomons, the Hawaii-based Pacific Tsunami Warning Centre said.
Aftershocks will continue but are expected to be smaller than yesterday's quake.
Australia's Parliamentary Secretary of Pacific Affairs, Richard Marles, says Australia stands ready to help with the relief effort.
"We're working very closely with the Solomon Islands, we're trying as best we can to get the information, as indeed they are, because this is a very remote part of the world," he said.
"As soon as we're in that position we'll be providing that assistance."
Irene Scott, an Australian Youth Ambassador for Development in Honiara, says many people in Temotu province are choosing to stay on higher ground.
"Last night the count was up to 30 or 40 aftershocks," she said.
"There was one at 5.15 this morning that was still 4.9 so for them, it's not yet stable ground in Temotu.
"I think a lot of people are choosing to stay on high ground and maybe wait until that's calmed down before they come down from the hills and assess what might have happened to them."
A 90-centimetre tsunami hit Lata in remote Temotu province, said the centre, which later cancelled warnings for other South Pacific islands, as well as for Australia and New Zealand.
An 11-centimetre wave hit Vanuatu, while a tsunami of around 50 centimetres reportedly hit New Caledonia. A small wave also hit Japan and Papua New Guinea.
Immigration officials in Papua New Guinea say asylum seekers were evacuated from the Manus Island processing centre during the warning.
Around 254 asylum seekers and staff were moved to higher ground after a strong earthquake in the Solomon islands, which prompted the alert in the Pacific.
An immigration department spokeswoman says everyone will remain at the evacuation point while reports of localised flooding are investigated.
Australia's foreign minister, Bob Carr, says Australia stands ready to help in the disaster-recovery efforts.
"We're ready to offer assistance which would include emergency food and shelter, medical supplies and help with reconstruction," Mr Carr said.
"Specifics will await discussions with the government of the Solomons."