I knew a guy who lived under the landing pattern for Los Angles International air port. He ran a garden gate type seismograph adjusted to about 20 seconds natural period. He said that even though it was in a little shed in the back yard, the seismograph had to be carefully covered with a good box or he would be affected by planes flying low overhead. Could there have been an non-audible pressure wave from the fireball that pushed the boom of the seismometer a tiny bit? I don't know if a shock wave from say 50 Km high event (presumably a very audible sharp step in pressure) gets converted to a slow rising pressure wave that humans don't hear at ground level. (I do know that a supersonic Hustler bomber flying at say 30,000 feet makes a very audible window rattling "BOOM" at ground level.) "Grasping at straws" Ed Thelen ajbv@............ wrote: > > Hi, I asked around and nobody heard any sounds except an observer > in the north of the state who claimed to hear a "hissing sound". This > type of comment does occur on some Fireball sightings. But no rattling > of windows or the like. So alas, I'll just have to say the measured "noise" > at the time of satellite entry will be put in the Hmmmm basket. I do agree > that the magnet effect is not really possible given the 1/r^3 decline in the > magnet strength with distance. Anyhow unit the next event. > > Thanks to John Hernlund and Ken Navarre. > > Arie > > Ken Navarre wrote: > > > On Sat, 29 Jan 2000 ajbv@............ wrote: > > > Apparently the object disintegrated in "mid-air" over the sea > > > approximately north of Kunnunura (near the border with the Northern > > > Territory). It was seen by people spread out about 2,000km across the > > > state. This is very unusual for a meteor as it suggests a 'grazing' > > > trajectory. We believe it was the entry of the Molniya 1-67, a Russian > > > communications satellite that was launched in 1986. > > > > Was there a sonic boom associated with the reentry event? If so, the > > "noise" you described could be related to that. Several years ago when > > "AREA 51" in Nevada was an active source of classified aerial activity > > southern California seismometers tracked several events that > > seemed to be associated with high altitude sonic booms headed from > > out over the Pacific and flying toward the Nellis Test facility in > > the Nevada desert. The booms left a "seismic footprint" across the > > seismic network. I recall some work being done to determine the altitude > > and direction of travel of the aircraft that produced the sonic booms. > > There were several events like this that occurred over several months. > > No one stepped forward to claim responsibility and it was assumed that > > the booms resulted from the operation of some classified project at the > > test site. > > _____________________________________________________________________ > > Public Seismic Network Mailing List (PSN-L) > > To leave this list email listserver@.............. with the body of the > message: leave PSN-L _____________________________________________________________________ Public Seismic Network Mailing List (PSN-L)
Larry Cochrane <cochrane@..............>