You're welcome! I actually had never heard about the impact before writing the post; it was kind of mind-bending to learn about - even (or especially?) as a professional earthquake scientist.
Hats off to the Canadians. There doesn't appear to be any overeaction by people to the quakes and all reports seem similar and reasonable. Pretty good for a populace that gets such few earthquakes.
Would a meteor impact like that shatter the underlying rock and generate a large series of radial cracks or faults?
However, my guess is that that kind of cross section is too simplistic, and that large parts of the crust as pervasively fractured in more irregular ways. Plus, given the central uplift in this crater, there might be secondary stages of deformation causing even more kinds of fractures, or rotating the existing fractures into other orientations! These two cross sections comparing simple and complex craters hint at this: https://www.researchgate.net/figure/a-Schematic-cross-section-through-a-simple-bowl-shaped-impact-crater-modified-after_fig29_260112404
Thank you for such a detailed summary of conditions in the area!!!!!!!!!!! I really enjoyed this. Interesting on potential effect of meteor impact.
You're welcome! I actually had never heard about the impact before writing the post; it was kind of mind-bending to learn about - even (or especially?) as a professional earthquake scientist.
Hats off to the Canadians. There doesn't appear to be any overeaction by people to the quakes and all reports seem similar and reasonable. Pretty good for a populace that gets such few earthquakes.
Would a meteor impact like that shatter the underlying rock and generate a large series of radial cracks or faults?
Yes, fortunately the shaking was pretty light.
My understanding is that meteorite impacts can cause radial fractures, concentric fractures, and conical fractures. There's a neat illustration on this page: https://deepimpact.astro.umd.edu/science/cratering.html
However, my guess is that that kind of cross section is too simplistic, and that large parts of the crust as pervasively fractured in more irregular ways. Plus, given the central uplift in this crater, there might be secondary stages of deformation causing even more kinds of fractures, or rotating the existing fractures into other orientations! These two cross sections comparing simple and complex craters hint at this: https://www.researchgate.net/figure/a-Schematic-cross-section-through-a-simple-bowl-shaped-impact-crater-modified-after_fig29_260112404
This might be my favorite earthquake breakdown yet! Meteor impacts, detailed geology, really interesting event. Loved it.
I can’t imagine a magnitude 6.5+ in eastern North America; that would sure cause a heck of a stir.
I'm shocked that 8 million people felt even a 3.8 quake, so a 6.5 would sure be something unfortunate.