Hi All, As I already told to Bj�rn off the list, here in Finland there is almost every winter news about strange holes on ice. Sized can vary a lot and in some cases there is many holes. In January 2001 there was three cases, one of which was discussed in this list too. That case was studied last summer closely (they dig up every rock of that site) but there was no meteorite in the bottom of the bond. I think that there was already news about one strange hole this winter too.
Many of them are claimed to be made by a meteorite, but when the bottom is checked by divers, nothing is found. That is obvious since they usually are not made by a meteorite. The most common reason for these holes is water circulation under ice deck or a underwater spring. So the ice has melted from below. In many cases there is lots of water on the ice around the hole, which looks just like something has hit the ice and splash water out from the hole. This happens because those holes often formed when water level is higher than ice surface e.g. water is pressurized a little bit. That happens usually when few warmer days occurs and water level rises. If that Atwater hole is 6 meters wide and there is no ice floating around, we can be quite sure that it was not made by an meteorite. There is photos of the hole which was made by the Bjurb�le meteorite (L/LL4 chondrite, TKW 328 kg) in 12. March 1899 off shore near Porvoo. The 4.25 m x 3.5 m hole through 0.5 m thick ice deck was filled with floating ice fragments. The hole was also surrounded by intense fracture zone and lots of mud from bottom was splashed some 20 meters away from the impact site. It has been quite a splash! Regards, Jarmo Moilanen www.netppl.fi/~jarmom/ > Hi Al, > > In the Atwater case (Lake Tadd) it is situated almost inside the town, with > built- > up area on the shores, so I would think the inhabitants would have known > if anyone were icefishing in the days leading up to the 17th. > > Also it had a very beautiful 'starburst' cracking pattern around it. > And the inhabitants of the town were awoken by a sonic boom in the morning, > just before this hole was discovered. > No ice material seemed to have been found on the surface around > the hole, it seemed like a tunnel was just melted through 18" of ice. > There were scientists from University of Minnesota, other geologists who > looked at the hole, but they didn't come up with a conclusion to what > had caused it. An ice-scientist that told the press that holes with > cracking patters are not unusual, said that these were normally > only one ich in diameter, and that the Atwater type was definitly > different from those. > Added to that, exactly 1 year later +~1 day, The Tagish Lake meteorite exploded > over northern Canada. Over the last years there have been many large fireballs > over northern part of North America (esp. Canada), in the few days around the > 17th of January. In Europe two very large meteors in 2001 and 2002 on the 17th. > I don't think one can attribute all these to just the fact there are cold clear > dark days in this part of the year... > There was also one on Wedensday this week in Canada, see earlier post > from Ron Baalke. > > For the Atwater case still one of the best theories (my guessing) could be > lightning, but wouldn't someone ivestigating this have found out if there really > was lightning in the night before. Btw, is lightning normal in central Minnesota > in the middle of January? > > It would help if a good picture of this hole was available by the way :-) > > Regards, > Bj�rn S�rheim > > See some information below: > > At 14:17 18.01.03 -0500, you wrote: > >Hi Martin and Bj�rn, > > > >It goes without saying (but I'll say it all the same :-) that some holes > could be from ice fishing, though there should be some signs of foot prints > and so forth. Also could blue ice break through from airliners? I would > think natural causes would be more in number than actual falls. > > > >--AL > > There is some more information here: > > http://www.channel4000.com/news/parker/news-parker-990121-113657.html > > Or this text posted to the meteorite-list 22/1-99: > > Minnesota town puzzles over hole in iced-over lake > > ATWATER, Minn.(Reuters) - The fire department in this Minnesota town is > investigating what caused a sound like a ''sonic boom'' and cracked > the ice covering Lake Tadd, officials said Thursday. > > Residents of an apartment building next to Lake Tadd, 40 miles West of > Minneapolis, said they were awoken before dawn Sunday by a sound like > a ``sonic boom,'' but waited until Tuesday to call authorities. > > They waited to report the incident because ``they were afraid all > their friends would think they were loony,'' city clerk Goldie Smith > told Reuters. > > Authorities said the hole was roughly 4 feet in diameter at the entry > point and surrounded by a starburst pattern, which Smith described as > ``pretty cool.'' The object may have been hot, melting through the ice > in a funnel shape. > > The hole has since frozen over. > > The fire department is going to wade in Saturday afternoon to find out > if anything crashed into the lake. > > Whatever it is -- speculation is that it was a fair-sized meteorite -- > several of Atwater's 1,100 residents have gotten their share of media > exposure at a time of year when excitement is scarce. > > ``It is a nice break from the cold and snow,'' said Smith. ''It's > winter; we'll take anything.'' > > > > ______________________________________________ > Meteorite-list mailing list > [EMAIL PROTECTED] > http://www.pairlist.net/mailman/listinfo/meteorite-list ______________________________________________ Meteorite-list mailing list [EMAIL PROTECTED] http://www.pairlist.net/mailman/listinfo/meteorite-list
