Wednesday, August 24, 2011

RE: Seismic Event

This will be interesting on an academic level because of the transmission of high frequency ground motions versus low frequency ground motions and the in-structure response.  The 20th floor of a building should not transmit a significant high frequency ground motion, but would transmit low frequency ground motions. 
 
The underlying rock of the East Coast is not highly fractured as the classic slip faults in California.  The ground motions (especially low frequency) do not attenuate quickly in unfractured rock.  This is the 20th earthquake of Modified Mercalli V or higher in Virginia since 1774.  There was a Modified Mercalli VIII in 1897 in Virginia. 
 
My son serves on an aircraft carrier, but is living on shore now in Norfolk, VA.  He felt it, but was not too alarmed. 
 
...The aircraft carrier sustained no damage;>)

Regards, Harold Sprague
 
> From: ahcene.djebli@shawgrp.com
> To: seaint@seaint.org
> Subject: RE: Seismic Event
> Date: Tue, 23 Aug 2011 19:05:03 +0000
>
> We felt in Charlotte NC, I was in 2oth floor of a building in uptown (Downtown) Charlotte Nc.
>
> -----Original Message-----
> From: Bill Polhemus [mailto:bill@polhemus.cc]
> Sent: Tuesday, August 23, 2011 2:26 PM
> To: <seaint@seaint.org>
> Subject: Re: Seismic Event
>
> Did NOT feel it in N. Central New Jersey.
>
> William L. Polhemus, Jr. P.E.
> Via iPhone 4
>
> On Aug 23, 2011, at 2:18 PM, "Kavsak, Paul M." <KavsakPM@westinghouse.com> wrote:
>
> > Did not feel it in Pittsburgh, must have taken an end around.
> >
> > -----Original Message-----
> > From: Alexander Bausk [mailto:bauskas@gmail.com]
> > Sent: Tuesday, August 23, 2011 2:17 PM
> > To: seaint@seaint.org
> > Subject: Re: Seismic Event
> >
> > Chicago folks report in Twitter that it was felt there too
> >
> > On 8/23/11, Joseph R. Grill <vveng@cableone.net> wrote:
> >> Virginia Beach, VA also
> >>
> >> Sent from my iPhone
> >> Joseph Grill
> >>
> >> On Aug 23, 2011, at 1:57 PM, "Stuart, Matthew" <MStuart@Pennoni.com> wrote:
> >>
> >>> I know you west coast guys will laugh, but ground shaking on the east
> >>> coast is pretty rare. Anyway we just had seismic event that was felt from
> >>> at least Philadelphia to Newark, NJ
> >>>
> >>>
> >>>
> >>> D. Matthew Stuart, P.E., S.E., F.ASCE, SECB
> >>> Structural Division Manager
> >>>
> >>> Pennoni Associates Inc.
> >>> One Drexel Plaza
> >>> 3001 Market Street, 2nd Floor
> >>> Philadelphia, PA 19104
> >>> Office 215-222-3000 x7895 | Direct 215-254-7895
> >>> Fax 215-222-0789 | Mobile 908-309-8657
> >>> http://www.pennoni.com | mstuart@pennoni.com
> >>>
> >>>
> >>
> >
> >
> > --
> > Alexander Bausk
> > Civil/Structural design & inspection engineer, CAD professional
> > MSc Structural engineering, Ph.C. Engineering
> > http://bausk.wordpress.com
> > ONILAES Lab at PSACEA
> > Dnipropetrovsk, Ukraine
> > Tel. +38 068 4079692
> > Fax. +38 0562 470263
> > bauskas@gmail.com
> >
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