Friday, May 31, 2013

Shallow focus Alaska earthquakes

There has been an interesting pattern of shallow focus Alaska earthquakes as of late, makes me wonder if it is a side effect of the subduction what I believe is a remnant  of the Farralon plate (that damn Farralon) that is being pushed by the Pacific plate under Alaska.  I believe there was at some point in the recent geologic history an active spreading ridge south of Alaska, just as in the case of the Juan de Fuca plate (which is also a chunk of the forlorn Farralon plate) off the coast of Washington and Oregon.  There may even still be an active margin, I did not take the time to do research on it for this little blurb.  But if there was a former plate chunk which is now mostly subducted under the North American plate in Alaska it could be beginning the drop off phase which would make for some interesting tectonics in that region.

Or I could be completely wrong.  As I stated before I really didn't do much research before hand and I would have to pull up about 100 years of seismic records including depths of earthquakes and ground level isostatic rebound measurements, and compare them with any rebound that could be attributed to removal of glaciation, and the resurgence of seawater, among other things.

Then after all of that I may be able to come to a viable conclusion, or possibly I would have to say all of the research was inconclusive, and my require further study.

It would make an interesting thesis.