Re: East Coast Earthquake 8-23-2011

[William Herrin <bill () herrin us>]

On Tue, Aug 23, 2011 at 5:48 PM, Owen DeLong <owen () delong com> wrote:
> A 5.8 (or 5.9, I've seen conflicting numbers)

Hi Owen,

http://earthquake.usgs.gov/earthquakes/recenteqsww/Quakes/se082311a.html#details

Originally reported as 5.8. Briefly upped to 5.9. Now back to 5.8.

> really isn't likely to do all
> that much damage, even on the East Coast.In California, anyone who
> has lived here for more than 10 years probably doesn't even feel
> anything less than a 5, and, it takes a solid 6 to really get anyone's
> attention out here. Natives mostly won't change their behavior for
> anything short of a 6.5.

Two points:

A. Our structures aren't built to seismic zone standards. Our
construction workers aren't familiar with *how* to build to seismic
zone standards. We don't secure equipment inside our buildings to
seismic zone standards.

B. The crust on the east coast is much more solid than on the west
coast, so the seismic waves propagate much further. Los Angeles
doesn't feel an earthquake north of San Francisco unless it's huge.
New York City felt this earthquake near Richmond VA. So yes, we're
seeing relatively minor damage... but we're seeing it over a much
wider area than someone in California would.

Regards,
Bill


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William D. Herrin ................ herrin () dirtside com  bill () herrin us
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