🚀 go-pugleaf

The Hawaiian islands continue to feel some aftershocks after Tuesday's
magnitude 5.2 quake eipcentered 50 miles west of the big island.

The aftershocks---largest being about 3.9 on the Richter scale, the rest
hovering around 3.0---went have been going on for a couple of days.

After the first quake at 1622 HST Tuesday, the 3.0 or greater smaller quakes
were recorded at 1745 Tues, 0315, 0542, 0756, 1055 and 1236 Wednesday.
Considerable lower-level activity also shows up on the seismographs.

Unlike the normal, smaller earthquakes which occur regularly on the big
island of Hawaii---the Hawaii Volcano Observatory weekly report routinely
plots epicenters of earthquakes > 3.0, but quakes greater than 4.0 are
rare---the 5.2 quake and associated aftershocks are not related to volcanic
activity.  Instead, these quakes are probably due to tectonic side effects
of isostatic equilibrium adjustments as the islands settle.

It's a bit too soon to correlate sea level measurements, but I'm fairly
sure that they will show that a couple of the islands settled a few mm in
the process...the long-term rate being about 13 cm per century.

-- 
Bob Cunningham
bob@hig.hawaii.edu