From: Dale Hardy 
To: 'Colin Stuart' ; 'Wolfgang'
; 'Bonnie Wickman'
; 'John Harris' ;
'Victor Dent' ; Andre Phillips
; psnlist 
Sent: Tue, 5 Mar 2013 22:05
Subject: Waves Generated by Russian Meteor

The National Science Foundation-has published an article on the meteor
that landed near Chelyabinsk, Russia.
http://www.nsf.gov/news/news_summ.jsp?cntn_id=3D127114&org=3DNSF&from=3Dnew=
s

Hi Dale,

     Thanks for bringing this bit of 'journalese' to our notice
---> the NSF press release 13-034 !

      I wonder if the NSF could use a new journalist - one that
actually bothers to check their facts ? !

    Quoting seismic 'pressure' waves :
    'Waves in the ground travel quickly at about 3.4 km / sec.'

     Well, NO they DON'T ! The velocity is about 6 km / sec down to
the Moho at roughly 10 km under the oceans and 35 km under the
continents. In the Mantle, the velocity is 8.2 km / sec at the top and
13.5 km / sec at the bottom. The outer core varies from 8 to
10.5 km / sec and the inner core from 9.5 to 11.5 km / sec.
    The transit time that you observe depends upon the ray path.
Look at the average travel/time graphs for seismic waves at :-
http://neic.usgs.gov/neis/travel_times/ttgraph.html

     Regarding Infrasound Detectors, a photo, reputedly supplied by
Iris, is entitled :-
'Sensor at an EarthScope TA station.'
     I suspect that the CTBTO would probably deny ownership ! This
seems to be a wreck - or is it not an Infrasound Sensor ? Did a
farmer plough it up ? And it is unlike ANY photos of CTBTO sensor
arrays that I have ever seen ! There are lots of GOOD photos of
Infrasound Systems on the www ! See
http://science.kqed.org/quest/2013/02/21/infrasound-takes-a-bow/
It took me less than 10 seconds to find this - thanks to Google.

    Regards,

     Chris Chapman
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