Saturday, June 2, 2012

Annual review of Ontario seismicity

It's totally dead in the States right now, so I'll do Ontario.  As we can see, there is still a very hard wall to the seismicity at the megathrust boundary that goes through Hamilton.  This goes on to the southern shore of Lake Erie, although only the lake events seem to be plotted.  I am always amazed that the seismicity is fairly uniform east of Hamilton, right to the next megathrust.  I think this terrane band must be 'crunchier' than the others.  We located a huge basin right at the east end of Lake Erie, and that might be producing the seismicity gap.

The fractal upper limit for most of the zone is probably M6.  The main question is the boundary fault under Hamilton.  Is it more uniform?  Can it produce an M7?  I think the answer will be found in Oklahoma, which has exactly the same band, and same pattern, activated by deep injection.  They are still injecting, Come Hell or High Water, and the boundary zone is right under the city.  They'll most likely get it before Toronto.

As you can see, water is the essential element to earthquake life.  The Grenville Front is only active in Georgian Bay and a bit of Lake Huron.  And we know what they plan for that megathrust right at Bruce!

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