Re: East Coast Earthquake 8-23-2011

[Scott Morris <swm () emanon com>]

Also, the quake on the east coast was much closer to the surface than
most west coast quakes, which could account for the feeling.

Scott (not a geologist)


On 8/23/11 6:13 PM, William Herrin wrote:
> 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