An earthquake of magnitude 7.5 has struck Papua New Guinea, according to the US Geological Survey.
About a half an hour later a second earthquake with a magnitude of 5.5 in the same area with a depth of 39 kilometres.
There were no immediate reports of damage.
The Joint Australian Tsunami Warning Centre showed that there was no threat of a tsunami for Australia.
Papua New Guinea sits on the Pacific Ring of Fire, an area known for seismic upheavals and volcanic eruptions.