SirJibAlot 0 Posted July 16, 2007 Share Posted July 16, 2007 Didn't feel it at all here in Osaka. But i was sleeping in and on only the 2nd floor of a 2 floor house, so that doesn't surprise me. Link to post Share on other sites
SirJibAlot 0 Posted July 16, 2007 Share Posted July 16, 2007 Soubs, but I would guess that the waves would have to travel farther up the mountain so you'd feel less than if at sea-level. Link to post Share on other sites
mina2 6 Posted July 16, 2007 Share Posted July 16, 2007 It was very strong here in Minakami (northern Gunma, just to the south of Yuzawa). As with the Chuetsu, it moves more here than in Yuzawa which seems to have a relatively strong base or whatever you call it. Go out into the valley though Muikamachi and it is much more prone to moving. Link to post Share on other sites
tsondaboy 0 Posted July 16, 2007 Share Posted July 16, 2007 Actually attenuation works best through sediments rather than massive formations. To give you a good example on that, it is the same as if you put a pillow over a clock and put your ear on the pillow to hear the ticking sound and try to do the same but cover the clock with a frying pan. Link to post Share on other sites
soubriquet 0 Posted July 16, 2007 Author Share Posted July 16, 2007 You'd want some compressibilty, and the water column won't give you that. I was thinking of attenuation of shear. That is trying to accelerate a mass horizontally by moving its base, and leaving the top behind. Link to post Share on other sites
TJ OZ 0 Posted July 16, 2007 Share Posted July 16, 2007 We had quite a big aftershock here about an hour ago as well. It's a strange feeling similar to being on a boat. I have now experienced a few over the last 9 months. I feel safe in my building as it it a very solid construction. Link to post Share on other sites
muikabochi 208 Posted July 16, 2007 Share Posted July 16, 2007 Here it was more like unwillingly being on a rickety old out-of-control wooden roller coaster. Link to post Share on other sites
Snow-Woman 0 Posted July 16, 2007 Share Posted July 16, 2007 It wasn't very strong here, but being so far away I don't want to imagine how such a quake feels when you are close by. Take care! Link to post Share on other sites
grungy-gonads 54 Posted July 17, 2007 Share Posted July 17, 2007 Been unlucky with them the last few years. Here's hoping for it to end sooner rather than later. Roppongi Hills lifts had a bad time of it again apparently. Link to post Share on other sites
gerard 6 Posted July 17, 2007 Share Posted July 17, 2007 hope eveyone is OK!!! Take care, folks Link to post Share on other sites
nzlegend 1 Posted July 17, 2007 Share Posted July 17, 2007 what is it with Niigata? are you guys low on Karma or what? the past few years have been hellish with quakes, floods, snowstorms. If any of you guys want move on down to Nara, you are welcome. Link to post Share on other sites
scouser 4 Posted July 17, 2007 Share Posted July 17, 2007 Very sad to see those scenes again. Link to post Share on other sites
soubriquet 0 Posted July 17, 2007 Author Share Posted July 17, 2007 I've found a focal mechanism solution for yesterday's main event. The fault runs parallel with the coast and the movement was an oblique thrust to the NW. What that means it that the rocks on the SE side of the fault slipped under the rocks to the NW. FWIW, thrust, or reverse faults have the greatest capacity to store strain, and therefore are responsible for the strongest earthquakes. Link to post Share on other sites
tsondaboy 0 Posted July 17, 2007 Share Posted July 17, 2007 Soubs, here are some first results regarding yesterdays earthquake. http://www.eri.u-tokyo.ac.jp/topics/niigata20070716/ It’s pretty early to be talking about fault geometry and staff, but all data point to an east dipping thrust. Probably on the northwest boundary of the Northern Fossa Magna basin. Link to post Share on other sites
soubriquet 0 Posted July 17, 2007 Author Share Posted July 17, 2007 I must have misread the beachball. You have a look. I haven't done a focal plane solution since about 1982. The USGS were the source. Link to post Share on other sites
tsondaboy 0 Posted July 17, 2007 Share Posted July 17, 2007 A Moment tensor solution always gives you 2 planes, like in the USGS pick. You can’t really say just by one solution, which is the plane that represents the fault. Usually the distribution of the aftershocks gives you a good idea of the geometry of the area that has slipped. The distribution up to now points to an East dipping thrust. Link to post Share on other sites
soubriquet 0 Posted July 17, 2007 Author Share Posted July 17, 2007 Damn, got the wrong one! That was in March Link to post Share on other sites
tsondaboy 0 Posted July 17, 2007 Share Posted July 17, 2007 Yap, you have the Noto peninsula event there. Link to post Share on other sites
soubriquet 0 Posted July 17, 2007 Author Share Posted July 17, 2007 Here it is. If it's east dipping, then it has to SE Link to post Share on other sites
muikabochi 208 Posted July 17, 2007 Share Posted July 17, 2007 Ah, I understand what you are saying... you're saying that there won't be another big one in this region while I'm still there. Good..... Link to post Share on other sites
soubriquet 0 Posted July 17, 2007 Author Share Posted July 17, 2007 Well, the strain has been released, so that part of the fault is relaxed. Strain is a slippery thing though. How long do you intend to stay in one of the most earthquake prone areas of one of the most earthquake countries? Link to post Share on other sites
Tubby Beaver 209 Posted July 18, 2007 Share Posted July 18, 2007 Can earthquakes trigger avalanches and if so have there been any of note in recent years? Link to post Share on other sites
SerreChe 2 Posted July 18, 2007 Share Posted July 18, 2007 Very good question. Yes, earthquakes do trigger avalanches although I think it is pretty rare to have casualties as a result. There was a case in my hometown quite a years back where 4 people got killed after an earthquake triggered an avalanche. Very very unlucky as earthquakes are very rare in that neck of the woods. Link to post Share on other sites
SerreChe 2 Posted July 18, 2007 Share Posted July 18, 2007 I wonder if the SJ mailbox survived the earthquake. May be a good opportunity to do something about it ;-) Link to post Share on other sites
soubriquet 0 Posted July 18, 2007 Author Share Posted July 18, 2007 Yes they can. One of the Niigata railways is closed by a landslip, as well as several roads. Avalanche isn't just snow. Link to post Share on other sites
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