On Friday, a magnitude 7.1 quake hit off the coast of Bougainville.
Another magnitude 7.6 quake struck 100 kilometres south of Kira Kira, the capital of Makira Province, in Solomon Islands early on Sunday.
The large quake and aftershocks off Solomon Islands generated a tsunami warning which was later cancelled.
The government’s National Emergency Operation Centre (NEOC) has reported zero casualties or damages.
Assistant Director of the Geophysical Observatory in Port Moresby, Chris McKee says there are reports that one small child was killed after a house collapsed in Bougainville during the quake.
He told Radio Australia’s Pacific Beat the damage in Bougainville appears quite widespread.
“The numbers are something like about 15 houses at Buin in southern Bougainville, but there are many other settlements in the area of southern Bougainville so it looks likely that there’s more damage than what has been reported so far,” McKee said.
He said water supplies were also hit.
“Water tanks commonly burst when there’s strong earthquake activity and some water tanks were actually shifted off their foundations.”
On Sunday a magnitude 7.5 quake also struck south of Kira Kira just before midnight and there have been a number of aftershocks since.
The US Geological Survey says the likelihood of casualties or damage from the quake was low.
McKee says it’s not unusual for aftershocks to continue after quakes like those in Bougainville and Solomon Islands.
“This is a typical pattern of aftershock activity. Normally with a large magnitude earthquake the aftershocks can continue for days or weeks or sometimes months,” he said.
The Solomon Islands Government has conducted aerial surveys of the tsumami-hit areas on Makira island to determine how much clean-up is required after the quakes.
The Australian High Commission has sent a civilian engineer and a disaster management expert to help with the assessment.
High Commissioner Andrew Byrne says the aerial surveillance confirmed there has been no significant damage to buildings and crops, and no signs of inundation.
“Importantly, that enabled Solomon Islands disaster management authorities to put that aside and come back to focussing on their response to the flooding disaster on Guadalcanal,” Byrne said.
The quakes have come as Solomon Islands continue to deal with the aftermath of devastating flash flooding on April 3.
The flooding killed at least 21 people and washed away homes and bridges in Honiara. At least two people are still missing.
There are still 50,000 to 60,000 people homeless - most without shelter and fresh water.
Major roads throughout Guadalcanal are ruined and bridges have collapsed, making it hard for emergency teams to assess the damage.