Hi Chris. Not sure if this is what you’re looking for. The data I used is listed as follows. What I found a little interesting was the longitude of some quakes. Even though a 2000Km radius was used the longitude stayed pretty tight for most of the quakes, but the latitude seems to be a little looser.

I don’t think you will see the clusters you’re looking for, but moving the center of the search 1000Kms in any direction could change that. Take Care…Don in creepy town

NEIC quake catalog
FILE CREATED: Wed Feb 25 21:01:08 2004
Circle Search Earthquakes= 722
Circle Center Point Latitude: 14.973S Longitude: 175.649W
Radius: 2000.000 km
Catalog Used: PDE
Magnitude Range: 6.0 - 9.0
Data Selection: Historical & Preliminary Data

PDE 1973 12 30 162129.30 -15.32 -173.08 33 6.20 Ms GS .... ....... 277
PDE 1973 12 30 163929.70 -15.51 166.64 10 6.60 Ms GS 5F.. ....... 1900
PDE 1974 03 18 105612.40 -14.93 -172.83 27 6.00 Ms GS 5F.. ....... 302
PDE 1974 03 23 142835.40 -23.93 179.78 535 6.50 UKPAS .... ....... 1099
PDE 1974 03 23 202551.80 -21.93 173.71 33 6.10 Ms GS .... ....... 1359
PDE 1978 09 06 040153.50 -20.14 168.71 36 6.30 UKBRK .... ....... 1753
PDE 1978 09 06 110743.10 -13.32 167.14 198 6.30 UKPAS .... ....... 1864
PDE 1982 09 04 020809.03 -15.43 -173.06 33 6.30 Ms GS 2F.G ....... 282
PDE 1982 09 04 133114.92 -25.52 -176.24 33 6.00 mb GS ..FG ....... 1167
PDE 1984 09 28 000334.54 -25.85 -175.91 21 6.80 Ms GS .FFG ....... 1202
PDE 1984 09 28 030346.85 -21.51 -177.80 363 6.20 mbBRK ...G ....... 757
PDE 1984 10 13 020347.51 -18.16 -175.61 36 6.20 MsPAS ...G ....... 352
PDE 1984 10 13 053238.86 -15.77 177.24 10 6.10 MLBRK ..FG ....... 766
PDE 1995 04 13 023437.95 -13.45 170.43 637 6.20 MwHRV ...G ....... 1508
PDE 1995 04 13 052724.91 -22.25 170.54 16 6.10 MwHRV ..FG ....... 1661
PDE 1996 11 14 075858.51 -11.38 166.46 109 6.00 MwGS ...G ....... 1975
PDE 1996 11 14 134738.11 -21.24 -176.62 191 6.20 MwHRV ..FG ....... 699