What made that quake significant was the duration (it went on for 15 seconds). That's a factor that supersedes the strength of the quake to an extent. Because a weaker quake will cause more damage over a long period of time.
Put it this way: Hit a wall with a hammer and you might cause a dent. Continually hit that wall with a hammer for 15 seconds and you'll probably break through.
The 2001 earthquake in Gujarat lasted for more than 2 minutes and killed around 20,000 people. The quake struck early in the morning during India's Republic day celebrations. The authorities said that the long duration caused more damage http://en.wikipedia.org/wiki/2001_Gujarat_earthquake
And when: the 7.1 struck about 4:30am Saturday morning--the outcome would've been very different if it had also struck at ~12:50pm weekday as the 6.3 did.
He meant as a duplicate of the earthquake that already devastated Japan. He wished he could downvote it as a duplicate, that is, that it hadn't happened again.
I appreciate that comment, but don't like how many up-votes it got. From my experience with Hacker News, the comments with the highest rankings are usually those that point out another post as stupid, instead of those that give valid information.
Nothing "stupid" was pointed out. It's a perfectly reasonable correction, although the original poster probably only phrased it that way since only "HNers" would see his post.
And I know what you mean, but I hope you at least realize the inherent hypocrisy in making a post only to complain about posts not yielding valid information.
I was sleeping at that time. I might have been woken up by the shake, but I don't recall it. Well, I'm in Tokyo, here it was "only" a 3 in the Japanese scale.
Like real estate, it is about location, location, location. Think of it as a lever - if properly applied, it can move a world.
There's also the emotional component. The Japanese population has been shaken by the initial quake, the tsunami, aftershocks, and the problems at the nuclear reactor. Adding another significant quake and tsunami (2m, last report), will further rattle already stretched nerves.
Anything over about a 6.5 or so is a pretty big quake. The '89 bay area (Loma Prieta) quake was just a 7.1 (and struck 10s of miles from downtown San Francisco). The recent Haiti earthquake was just a 7.0.
It depends on many factors. I was in a 6.8 earthquake in Seattle in 2001 that did some fairly significant damage to a few buildings in Pioneer Square, but otherwise was just a scare and an inconvenience. At the time I read that we got off "easy" because of the depth of the epicenter. An earthquake of similar magnitude had hit Turkey a few years before that and did a lot more damage.
Likely they did, but probably no more than would have happened anywhere in high-winds.
I know here in the Greater Toronto Area can get hit by blackouts frequently because of tree falls. Having moved here from the UK I don't get the idiotic notion of letting trees grow through your power lines because inevitably a branch or the whole tree will fall and knock out power. I've seen a few trees that are so big that no matter what way they fall, they'll knock out power to both sides of the street.
It's surely caused by the earthquake, but it's hard to tell if it would only be cause by the earthquake. You've got to draw a line between "act of god" and an "act of man" for being stupid enough to let an earthquake, windstorm or snowstorm knock your power out.
There are earthquakes of magnitude 6 or larger quite often, probably every week. And under 6 (like the 5.8) are even more common.
I'll hold my assertion that it seems to be a more active week than normal in the seismological world.
Your comment adds nothing here and is not backed up by any evidence; "probably every week" does not count as evidence. The majority of the number that the USGS counts includes quakes below the ocean. http://earthquake.usgs.gov/earthquakes/eqarchives/year/eqsta...
The USGS calls anything 6+ "large". A magnitude 6 earthquake can be deadly. Even magnitude 5 < can be deadly. There are factors at work depth of the quake as well as other factors, like location where it hits.
From the submitted link, as I see it at this moment: "This earthquake can be considered an aftershock of the March 11, 2011 Mw 9.0 Tohoku earthquake. The aftershock sequence of that event has been ongoing since March 11, and has included 58 earthquakes of M 6 or greater up until April 7 2011, two of which were greater than M 7 (M7.7 and M7.9, both on March 11)."
I'd hesitate to say 'just', and there is a rigorous definition of aftershock that this may or may not fit, but it's very close to the big one last month and certainly related to it.
So I'd go with 'yeah, basically' in the absence of a seismologist telling me otherwise.
In January there was a 6.9 quake here in Chile, and seismologists said it was an aftershock of the big earthquake of one year earlier. For what I recall, any earthquakes within a couple of years of the big one are most probably aftershocks.
It's hard to find useful information on line about this. But I guess that the lack of information in itself probably means that geologists aren't particularly worried about it.
Saw some posts on twitter that nhk switched to a documentary about cranes about 40mins ago, but channel 1 here was still showing coverage until a couple minutes ago. Don't people mean NHK G when they mention NHK?
Tsunamis (and waves in general) don't actually move the water they're traveling through over any significant distance. It's the wave's energy that's moving, not the water itself.
Exactly. The water level is raised, and then water "falls" along the path of least resistance, in the case of shore - it will certainly flow onto land.
True, but I imagine that Japanese infrastructure may have been compromised by the earlier earthquake, making this one more dangerous than it would be otherwise.
Much like the Flu is usually no big deal, but can easily kill people with any sort of immuno-deficiency.
There was some pretty strong shaking in Tokyo, warning of tsunami up to 2m in Miyagi, 1m elsewhere along the east coast down to Chiba. The tsunami will have arrived in Miyagi by now.
I think this one is OK -- and personally if I see another article about how awesome or evil or dickish (or whatever) Facebook/Twitter/Microsoft/Google are, or about how shitty News Corp handled Myspace, or simply showbiz/yellow journalism junk (i.e. pictures of Jobs meeting with Schmidt) I think I'm going to puke.
But there's lots of offtopic articles (i.e. not related to startups or hacking) everyday -- complaining about it just adds more noise and is completely pointless.
I didn't complain. Simply took action to help fight noise and hoped to rally others to do the same. I consider a report of Yet Another Earthquake in Japan to be off-topic. We have mainstream news sources for that. And if it's truly important, that sort of news will find us. Through other channels.
Lets move the discution to the definition of some word. Lets call everyone with a different opinion stupid. Lets put out your opinion and try to close the thread ...
>NHK World TV reports that external electrical power supply has been cut in two of the three lines servicing the Ongawa nuclear power plant in the Miyagi prefecture because of the quake.
A 9.2 is 2.5 gigatons.