Saturday, December 24, 2016

Ontario Seismicity in Review 2016

Southern Ontario has seismicity that mirrors Oklahoma but at a natural rate.  But if they started to disturb the Precambrian water, like with nuclear waste repository at Bruce, then it would act up.  At a natural rate, we would expect an M7 every thousand years or so, but it was probably a thousand years since the last one.  As I have said, 'We don't give a sh*t about no earthquakes.'.  As such, we have a seismic capacity somewhere around Italian rubble houses.  I have written many scenarios for our next M7, and let it rest at that.

The Toronto megathrust and hanging wall zone are very clear, and are activated by water from the lakes.  The Buffalo zone practically runs into the Toronto hanging wall, and makes a nice line.  If you use a topography map, you can trace these things right down to New Madrid and Oklahoma.  They are characterized by a broken and weathered zone (hanging wall), right next to a solid wall that forms a ridge or cliff (footwall).

This year, we finally get a picture of the last megathrust to the West, the famous Grenville Front.  Now, the geologist with the Bruce black hole pooh-poohs this by saying it's off into the lake, but it is the same as the others, and has a hanging wall zone.  It's just that this one is on dry land, and has little opportunity for a natural seep.  Down in New Madrid, we have the river, and in Oklahoma, we have injection.

New Madrid is no threat for another thousand years, but OK is nearly tomorrow, and Toronto will get a good hunk of grease from OK, and will let go soon after that.  If you are a tiny bit worried about the 1 in 500 per year chance of destruction, take a pill, and move to the footwall.  :)  Otherwise, enjoy your happy life downtown.  If you live in a cheap condo, insure for the whole value, and know that you'll walk away from it.

**I just read that the condo corp is responsible for earthquake insurance.  You are responsible for contents, water damage, etc, car being flooded, etc.  I would add living expenses, and figure that that they walk away from the building.

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