Hi Michael. I have been looking for some data for PNG. I have found some, but so far it hasn’t been of much use. The magnitudes of the quakes weren’t or aren’t known. The table below was taken from the Russian Academy of Sciences' Tsunami Laboratory and an article by Everingham (1974) and so far is the only data that I halfway trust to be accurate. As you can see its not complete or up to date.

It wasn’t until 1940 that a real comprehensive study for the earthquakes and volcanic eruptions in that area was started. So far I haven’t been able to find any data related to those studies.

I did however find this article buried in among others and thought it would be interesting to some.

“On July 17, 1998, three mountainous waves pounded the northern coastline of Papua New Guinea killing at least 2,500 people. Survivors of the tsunami described it as a wall of water barreling toward shore. The largest wave swept over shore at speeds of up to 20 km per hour for more than a minute. Debris hanging from the tops of palm trees indicated that the waves reached heights of 14 meters, taller than a four-story building.

What caused this deadly tsunami? Researchers concluded that an earthquake itself could not have caused such large waves. The quake that preceded the tsunami measured 7.1 on the moment magnitude scale, meaning it was strong but not out of the ordinary. About every 3 weeks tremors of this size strike somewhere in the world.
Costas Synolakis, a researcher at the University of Southern California and co-leader of a science team that visited Papua New Guinea in early August, believes that the earthquake triggered an underwater landslide that in turn generated the giant waves. This is bad news for North America with a coastline that stretches from California to the Pacific Northwest and southern Alaska, which has many shores similar to Papua New Guinea.
The Northwest coast of America is thick with small coastal faults capable of producing moderate quakes and underwater slides in the steep-walled canyons offshore. These faults were never taken seriously, but in light of Papua New Guinea researchers have to view these faults as potential threats”.

It is interesting that this should be thought about now when there is already a reported case of just such an occurrence on the West Coast. This was the Santa Barbara Channel quake in Dec of 1812 and was a 7.1M. The following was taken from NEIC.

“This major earthquake caused damage in Santa Barbara, Ventura, and northern Los Angeles Counties. One fatality was reported, but many lives probably were saved by a strong foreshock about 15 minutes earlier that sent alarmed residents fleeing from buildings. The earthquakes also may have generated a tsunami because there were several reports of sea waves following the earthquakes. The sea waves reportedly did not cause loss of life or substantial loss of property.”

I do have some favors that I can call in, but would rather wait and see if someone else can find some data to add to this. Take Care…Don in creepy town.