Quakes Triggering Quakes
Then there is the matter of whether the South Pacific cluster is in any way "teleconnected," as seismologists say, to the 8.0 magnitude Samoan event of Sept. 29 or the 9.2 magnitude Sumatra-Andaman event of 2004.
"It's well within the realm of possibility," Hough said. "The waves come tumbling through and disturb the fault zone and it causes little earthquakes...The trouble is, how do you prove it?"
Other researchers working on quake-triggered-quakes tend to agree.
"It is hard to guess whether there are teleconnections between the Samoa earthquake, the Sumatra earthquake and this earthquake swarm," said seismologist Fenglin Niu of Rice University. "Considering the fact that the first two earthquakes are almost 9,000 kilometers away from each other and the Samoa earthquake is much smaller than the 2004 Sumatra earthquake, probably there is little connection between the Samoa and the Sumatra events."
On the other hand, the Vanuatu swarm is less than 3,000 kilometers away from the Samoa event, so they could be related, Niu said.