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NZ Seismograph network lit up from a very large M8.2 quake - a couple of hundred km E of Fiji an hour and a half ago.
USGS has depth of this quake at 563 km. One of the largest "deep" (could be the second largest?) quakes ever recorded.
The three little blips commencing 1/2 hour or so afterwards are aftershocks - around M5.
Deep focus earthquakes don't normally have much aftershock activity - if any.
There's also not a consensus on what causes them - as explained in that link.
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Pretty rare also for such an aftershock sequence - including a M6.8 and 6.3. Deep quakes often don't have any at all. OTOH smaller aftershocks at those depths probably aren't very noticeable - except with instruments.
I guess some geologists will be quite excited about this - the characteristics of the aftershocks might help them better understand WTF is actually going on down there - which might help explain better what goes on up here sometimes.
That main shock energy was the equivalent of ~ 30 megatons of TNT - and it's not really known how it let rip.
"Phantom" quakes automatically triggered by GNS network, following a large quake S of the Kermadecs. An interesting number of "felt" reports in the NI - I presume they weren't dreaming - so the place must have had a bit of a wobble. It's showing as M7.0 on USGS site, about 100km depth. No tsunami threat.
Hmmm : Stuff puts out an (apparently incorrect) headline:
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There's an EQ search tool on the Geonet site. This was the result of 2 years from 1 Jan 1984:
So there's nothing showing there, a few small shallow quakes to the NW, nothing close to the mountain, some deep quakes to the south - nothing at all suggesting that "the mountain was rumbling".
It sounds like there might have been a bit of a back-story to the RNZ article - probably something being stirred up for political reasons - not geological reasons.
There's a paper available here discussing a new monitoring network operating in the early '90s. There's no mention there I could find of any "pending eruptive seismic activity" in the mid '80s.
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