Anyone know if Alvaro is OK?
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From: Ron Mayer on 28 Feb 2010 15:04 Jaime Casanova wrote: > At Saturday, 02/27/2010 on 4:21 pm "Marc G. Fournier" <scrappy(a)hub.org> wrote: >> On Sat, Feb 27, 2010 at 10:45 PM, Alvaro Herrera <alvherre(a)alvh.no-ip.org> wrote: >>> Is there a higher then normal amount of earthquakes happening recently? >>> >> Re: the more frequent earthquakes, yeah I was thinking the same today. An >> actual scientific study would be more useful than idle speculation though > > This is a technical list so i won't insist on this but those of you > that wanna give a try can read Matthew 24:3, 7, 8 and Luke 21:11 I find these links useful: http://earthquake.usgs.gov/earthquakes/eqinthenews/2010/ http://earthquake.usgs.gov/earthquakes/eqinthenews/2009/ ... I note an 8.1 in Samoa in Sep 2009 no 8.x's in 2008 an 8.5 in Sumatra Sep 12 2007 an 8.0 in Peru, Aug 2007 an 8.1 in Solomon Islands Apr 2007 an 8.1 in Kuril Islands Jan 13 2007 an 8.3 in Kuril Islands Nov 2006 an 8.7 in Sumatra, March 2005 an 8.1 in Macquarie Island Dec 2004 an 8.3 in Hokkaido Japan, Sep 2003 So yeah, if we're counting 8.8+'s this year's worse than usual; but 2005's 8.7's close. But if we're counting anything over 8.0, 2007's up there as well. -- Sent via pgsql-hackers mailing list (pgsql-hackers(a)postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
From: Steve Crawford on 1 Mar 2010 13:51 Marc G. Fournier wrote: > > Is there a higher then normal amount of earthquakes happening > recently? haiti, japan just had one for 6.9, there was apparently one > in illinos a few weeks back, one on the Russia/China/N.Korean border > and now Chile? Random events come in bunches - something I always stop to remind myself of whenever there is a sudden bunch of quakes, celebrity deaths, plane crashes, etc. Especially with relatively unusual events like great-quakes and plane crashes, it can be tough to see if there is any signal in the noise - a job I have to leave to experienced statisticians. The world averages one "great" (8+) earthquake/year which, of course, means some years like 2008 have none but 2007 had four. 7-7.9 like Haiti or our own Loma Prieta quake are far more common averaging ~17/year. Haiti is a catastrophe not because the quake was of unusual size (it barely made it into the 7-7.9 category and released less that 1/15 the energy of the Chile quake) but because the hypocenter was both shallow and fairly close to Port-au-Prince combined with terrible construction standards and virtually non-existent emergency-response capabilities in Haiti. Some general quake stats/facts are here: http://earthquake.usgs.gov/earthquakes/eqarchives/year/eqstats.php Cheers, Steve -- Sent via pgsql-hackers mailing list (pgsql-hackers(a)postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
From: Greg Stark on 2 Mar 2010 08:34
On Mon, Mar 1, 2010 at 11:11 PM, Chris Browne <cbbrowne(a)acm.org> wrote: > Nobody really notices the carnage on the highways, because, > stochastically, there are such a large number of events, both positive > and negative (e.g. - millions of people making it home safely, and a > tiny number that don't) that it's difficult for there to be a > sufficiently large number of "adverse events" to notice. I don't think the number of positive events factors into it. It's that the law of large numbers kicks in and the rate of death is pretty much constant. Every now and then there's an atypical weekend for a given town or city and the death toll spikes and people do in fact notice. Suddenly the news is filled with stories about the carnage the prior weekend and various imagined causal factors just like when the stock market goes up or down and the news people try to explain why. > People are a lot more worried about terrorists than about car accidents, > even though the latter are *enormously* more likely to cause one's > demise, by a *huge* factor. (This mismeasurement irritates me a lot, > particularly when I visit airports!) Well there is also a difference here. Because there is an active opponent in the terrorism case the security has non-linear game-theory effects. In the car safety case you could spend 10x as much money and reduce accident death rates by 1/10th. But there's a point of diminishing returns and an optimal value somewhere. In the case of terrorism it may well be the case that if you spend any money on security you must spend a lot of money for it to reach the threshold at which terrorists redirect their attacks elsewhere. Earthquakes are of course not in that category. They just occur rarely enough and then our perception of their severity is heavily influenced by where they occur so clumpings are just inevitable. -- greg -- Sent via pgsql-hackers mailing list (pgsql-hackers(a)postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers |