Scientists are intrigued by a cluster of earthquakes that circled the Pacific during the past two days, but seismologists don't believe most of them are related.

From late Saturday night, the edges of the Pacific Ocean felt tremors of magnitude 5.0 or greater in the area of Japan and the Philippines to the west, the Aleutians to the north, the Galapagos to the east, and Vanuatu and Papua New Guinea to the south.

"It's been pretty exciting," said Charles "Chip" McCreery, director of the Pacific Tsunami Warning Center in 'Ewa Beach.

Only a quake Sunday afternoon, Hawai'i time, off Japan caused local damage. At least nine people were reported killed.

None of the recent shakers generated Pacificwide tsunami likely to affect Hawai'i.

Most of the earthquakes were comparatively weak, but it is unusual to see so many in the 5 and 6 range clustered together. McCreery said it is unlikely that quakes in, say, Japan and in the Aleutian chain thousands of miles away are related.

"We think these are random clusters" and that it was just happenstance that a dozen of them occurred within two days, he said.

For some in the quake-watching community, what's more interesting is what hasn't been happening.

It's been an unusually long time — nearly four months — since there has been a big earthquake of magnitude 7 or more anywhere in the world. The last one was a 7.1 quake March 25 in Vanuatu. Again, that doesn't necessarily mean a bigger one is coming, or that one isn't. There was a four-month lag last year, which ended with a 7.1 quake that killed two people in Taiwan on Dec. 26, 2006.

Meanwhile, early yesterday morning, the Big Island was shaken by a comparatively small earthquake, of 3.2 magnitude, under the southeast flank of Kilauea. It did not appear to be directly related to the eruption of the volcano, said Jim Kauahikaua, who heads the Hawaiian Volcano Observatory.

Most likely, the earthquake represented slippage under the southern flank of the volcano, said Dave Wilson, seismic network manager for the observatory.

"This type of earthquake is associated with slippage. It's lined up with quakes we've been seeing along the south flank faults," he said.

Wilson said the seaward part of the southern flank of Kilauea is constantly slipping into the ocean. He said yesterday's earthquake could be indirectly linked to the Kilauea eruption because earthquakes that have been part of the recent changes in the eruption pattern may have shaken up the area and helped destabilize the fault zone.

Reach Jan TenBruggencate at jant@honoluluadvertiser.com.