[meteorite-list] Initial analysis of Norway/Sweden/Finland bolide

From: Matson, Robert <ROBERT.D.MATSON_at_meteoritecentral.com>
Date: Wed Jun 14 10:17:17 2006
Message-ID: <A8044CCD89B24B458AE36254DCA2BD07A4EB2D_at_0005-its-exmp01.us.saic.com>

Hi All,

Finally we can close the book on the ridiculous notion that that
photo represented evidence of a meteorite impact. Time to move on
to the much more important piece of data revealed by Bjorn Sorheim --
that at least *three* seismic stations recorded the terminal burst
(or possibly just the passage) of the bolide:

1. Kiruna in northern Sweden
2. Lulea in northern Sweden at the north end of the Gulf of Bothnia
3. Karasjok in the northern county of Finnmark, Norway, close to
   the border with Finland

Stations 1 and 2 are about 165 miles apart, with Kiruna NNW of
Lulea. Stations 1 and 3 are about 175 miles apart, with Karasjok
northeast of Kiruna. The Karasjok station recorded the sound/
seismic disturbance at 02:13:25:

<http://www.astro.uio.no/ita/nyheter/ildkule06/ildkule06.html>

I haven't yet been able to find corresponding seismic data for
Kiruna or Lulea.

>From what I've been able to read, the only known photograph was
taken at ~2:05am by farmer Peter Bruvold in Lyngseidet in which the
meteor trail moves from upper left to lower right. (Lyngseidet is
a little east of Tromso and about 130 miles west of Karasjok).
Unfortunately, it doesn't say which direction he was pointed.
Since the left side of the picture is brighter than the right,
it probably means he was facing somewhere between northeast and
south -- consistent with the now-discounted notion that an
impact occurred east of his location in Reisadalen.

Several websites say he heard a sonic boom about 7 minutes after
he saw the bolide. This would suggest that either the closest
approach of the bolide to the farmer was about 80-90 miles (rather
unlikely given the steep trajectory), or the sonic boom he heard
was associated with a terminal burst 80-90 miles away from him.
Trouble is Karasjok, being 130 miles east of Lyngseidet, should
have registered a sonic boom noticeably earlier than did the
farmer if the bolide was truly on an easterly heading. Also,
it would have been rather surprising that the station in Lulea
would have picked up anything if the bolide was traveling east.

Pulling all this together, I think it much more likely that the
farmer was actually facing more to the east-southeast, and that
the terminal burst was southeast of him, southwest of Karasjok,
northeast of Kiruna, and well north of Lulea. If I'm right,
Lulea would have been the last station to record the burst,
and the actual impact would have been somewhere close to the
thin peninsula of Finland separating northernmost Sweden
from Finnmark (Norway).

--Rob
Received on Tue 13 Jun 2006 05:12:09 PM PDT