Don

Beautiful graphics, and useful too.

I was wondering why the Kermadecs are so active seismically, and the graphics fill in some gaps in my knowledge.

I have suspected from the sequences of quakes in that region that there is a "fault" from the Kermadecs to Vanuatu, the Loyaltys, etc., even if modified by higher ocean floor than the Tonga Trench and that one from the Solomons to Vanuatu.
The many large quakes in the region point to crustal instability, and this graph suggests a counter-clockwise twisting pivotal in mid New Zealand. The motion around Fiji would thus be clockwise and upward, explaining the big quake at the Samoa elbow (despite the Flinn-Engdahl designation of Tonga, on occasion). The Fiji motion would thus aggravate the Loyalty situation, by encouraging subduction from the east.

Dave's report is verifiable by counting global 7M+ quakes and watching for vertical movement in islands in media reports such as EARTHWEEK.

Cool!
Donald