In a message dated 2007/09/19, rez@.................. writes:

> On Wed, 2007-09-19 at 15:36 +1200, Mark Robinson wrote:
> > Brad Douglas wrote:
> > > On Tue, 2007-09-18 at 16:56 -0700, Bob Hancock wrote:
> > >> I believe there are some physicists that follow this site.  I would 
> like to
> > >> know what they think about the energy involved to make a crater 30 
> meters
> > >> across and 6 meters deep, and how that would translate into magnitude.
> > > 
> > > A 5m crater releases on the order of 4.2-4.6GJ of energy equivalent to a
> > > Richter M2.
> > > 
> > > There is little literature on craters of this size, so a little
> > > extrapolation is in order.  I would say a 30mx6m crater would generate
> > > no more than a M3.
> > 
> > Computing Projectile Size from Crater Diameter
> > http://www.lpl.arizona.edu/tekton/crater_p.html

Hi there,

       You can pick up both sonic booms and impacts with a seismometer. Since 
a meteor is coming in a very high speed and burning up as it does so, sorting 
out which effects are dominant might not be so easy. Does the signal have a 
couple of peaks separated by a few seconds? The velocity of sound in air is 
much slower than that in the earth.

       Regards,

       Chris Chapman   
In a me=
ssage dated 2007/09/19, rez@.................. writes:



On Wed, 2007-09-19 at 15:36 +12=
00, Mark Robinson wrote:

> Brad Douglas wrote:

> > On Tue, 2007-09-18 at 16:56 -0700, Bob Hancock wrote:

> >> I believe there are some physicists that follow this site.&nbs=
p; I would like to

> >> know what they think about the energy involved to make a crate=
r 30 meters

> >> across and 6 meters deep, and how that would translate into ma=
gnitude.

> > 

> > A 5m crater releases on the order of 4.2-4.6GJ of energy equivalen=
t to a

> > Richter M2.

> > 

> > There is little literature on craters of this size, so a little
> > extrapolation is in order.  I would say a 30mx6m crater would=
 generate

> > no more than a M3.

> 

> Computing Projectile Size from Crater Diameter

> http://www.lpl.arizona.edu/tekton/crater_p.html




Hi there,



       You can pick up both sonic booms and im=
pacts with a seismometer. Since a meteor is coming in a very high speed and=20=
burning up as it does so, sorting out which effects are dominant might not b=
e so easy. Does the signal have a couple of peaks separated by a few seconds=
? The velocity of sound in air is much slower than that in the earth.



       Regards,



       Chris Chapman