guess i'd better take the long board for that one?!
i will be gradually switching over to yahoo mail (it has 100 FREE megs of storage). please cc to: [EMAIL PROTECTED]
>From: "Sterling K. Webb" <[EMAIL PROTECTED]> >To: Meteorite-List <[email protected]> >Subject: Re: [meteorite-list] LANL: Meteor Could Cause Big Tsunami >Date: Wed, 12 Jan 2005 09:58:36 -0600 > >Hi, > > The graphs in "Tsunami Generated by Small Asteroid >Impacts" by Hills, >Nemchinov, Popov, and Teterev in the UofA Press >collection "Hazards Due To >Comets and Asteroids" (1994) show that for a 800 meter >soft stone object >impacting in Atlantic deep water at 20 km/sec (average >velocity for an >impactor), the height of the ocean wave 1000 kilometers >away from the point of >impact would be 100 meters. Upon reaching the
shallows >which surround Florida, >the run-up height would increase to approximately 1000 >meters (one full order of >magnitude). > Yes, friends, that's one full kilometer of water. I >think that would make it >all the way cross the peninsula, don't you? I believe >that hill near Micanopy is >about 95 meters high, which leaves lots of room (905 >meters) for water overhead! > > An 800 meter iron meteorite in the same place, same >velocity, would produce >a water wave of 340 meters, ramping up to a 3400 meter >wave on shore. That's a >wave over two miles high! Hello, Atlanta! Hello, >Memphis! Hello, Houston! Heck, >I'm only 447 feet above sea level here in Illinois! How >high did you say Denver >was? > Let's say the models are off by a factor of two, or >four or even ten; it's >still Goodbye, Florida! > Actually, Chris
is right; there is on-going dispute >about impact tsunami >models. The dispute originates in the fact that it is >difficult to find >geological evidence for the very large scale tsunamis >predicted for impacts that >must have geologically frequent, hence suspicions have >arisen that the models >are exaggerated. On the other hand, what are the >geological evidences of really >ancient tsunamis and how easy to find would they be? > I recall reading many years ago an account of using >steam hoses to excavate >a layer at a site in Alaska in which flora and fauna >were churned up together, >mammoths and tree trunks, all jumbled and squashed in a >tangled mass, and the >author wondering what could have caused it, earthquake, >landslide? All of a >sudden it sounds a lot like a tsunami to me. In fact, I >recall a number of >fossil
sites where remains are jumbled and compressed >and the investigators >always attribute it to "flash floods" or "landslides." >Hmmm. > Would a Florida tsunami only 330 feet high feel much >better to a person than >a Florida tsunami 3300 feet high, if it was just you >standing on the beach at >Jupiter, waiting for it to hit you? In practical terms, >I think the results >would be pretty much identical... > >Sterling K. Webb >------------------------------------------------ > >Chris Peterson wrote: > > > Are you sure about that? There is some question about the dynamics of the > > water displacement- that is, most of it goes up, not out. And that total > > volume of water is somewhere between a few tens and few hundreds of cubic > > kilometers. Contrast that with the recent Indian Ocean event. The shift in > > the
ocean floor resulted in the displacement of over 1000 cubic kilometers > > of water, and produced waves in most locations of 3-5 meters. > > > > While an asteroid impact seems like a dramatic thing, it is far from obvious > > to me that tsunamis larger than 10s of meters would be a natural result. > > Since simulations seem to show everything from a few meters to 100 meters or > > so, I think I'll just reserve judgment until those simulations settle down. > > > > Chris > > > > ***************************************** > > Chris L Peterson > > Cloudbait Observatory > > http://www.cloudbait.com > > > > > >______________________________________________ >Meteorite-list mailing list >[email protected] >http://six.pairlist.net/mailman/listinfo/meteorite-list ______________________________________________ Meteorite-list mailing list [email protected] http://six.pairlist.net/mailman/listinfo/meteorite-list
