Hey Jerry


I can appreciate depth accurcay may be a bit difficult but I am suprised
that their 

epic location is pretty poor. What I really cant understand is why they
dont seem 

to use the location data from the local network operation
organisations.


This is so apparent back in my home country of New Zealand.  The
locations and 

magnitudes bear NO resemblence at all to the data produced by the main NZ


organisation, the GNS (Geological and Nuclear Sciences).  These guys
have a 

good dense network right across NZ and escpecially in the Christchurch
region 

over the last 14 months since all those large destructive
events.


  The USGS reported magnitudes are often up to 0.5 of a magnitude or
more out.

And usually its always lower. and up to 10 km of horizontal
distance out.

a recent aftershock was Mb 5.5 (GNS) reported at Mb 4.7 by USGS 
and  ~10km 

 further east... offshore rather than onshore.... thats a hell of a
difference !!!


 So I think to myself, if they are that far out with their reports
for regions I have access to real data from. How bad are their reports
from all those events from 

the rest of the world ??


cheers

Dave

Sydney







At 10:59 AM 6/11/2011 -0600, you wrote:

I have a question as to how
accurate are the Depth and Location reports coming from
USGS.  

 

As I understand it, USGS reports =E2=80=9C5 km=E2=80=9D as a depth which=
 could be
anywhere from the surface to 26,400 feet down.  I also wonder how
accurate the epicenter is pinpointed.  Anyone know?

 

Jerry