Hard News by Russell Brown

Read Post

Hard News: #eqnz: Okay?

106 Responses

First ←Older Page 1 2 3 4 5 Newer→ Last

  • linger, in reply to Paul Campbell,

    One month after the Tohoku quake (and two months after the second big Chch quake, which had had no small amount of media coverage because of the number of Japanese victims) one of my colleagues actually asked me, with some surprise,
    “Oh, do you have earthquakes in New Zealand!?”

    Tokyo • Since Apr 2007 • 1930 posts Report Reply

  • steven crawford,

    When I was down at the supermarket today, I noticed people buying large amounts of bottled water. Since the flooding is old news, that would make sence, perhaps. But plenty of rain is forecast.

    Atlantis • Since Nov 2006 • 4414 posts Report Reply

  • TracyMac,

    On the wry laugh front, today wasn't really the best day for Air NZ to be emailing their Aussie subscribers, "... It's time to admire NZ - 48 hour sale."

    Email received 5:02 am Straya (east coast) time. :-)

    Canberra, West Island • Since Nov 2006 • 701 posts Report Reply

  • steven crawford, in reply to TracyMac,

    Well to be fare, It's all middle earth and adventure over here:-)

    Atlantis • Since Nov 2006 • 4414 posts Report Reply

  • krothville, in reply to linger,

    That's weird, my vice-principal had the staffroom tv turned on to the live coverage of the Feb 2011 Chch quake. I thought it got a lot of coverage in Japan because of the Japanese students who were killed. I guess your colleague somehow just totally missed it?

    Since Sep 2014 • 73 posts Report Reply

  • Russell Brown,

    Attachment Attachment

    Bloody hell! Turns out Fiona was half-awake, heard the deck creaking and vaguely wondered if someone was walking around out there.

    So we went out and looked … and we appear to have a tiny bit of earthquake damage. In Auckland! Pretty sure that gap didn’t look like that yesterday.

    Testament to the energy released at the epicentre.

    Auckland • Since Nov 2006 • 22834 posts Report Reply

  • Prudence, in reply to TracyMac,

    It's the lintel (150 to 200mm deep) spanning the distance above the door that offers protection. Some houses have door openings that are full height, (the height of the wall) in which case it will be the truss above the opening that provides support. A doorway is a good place to be in an earthquake.

    New Zealand • Since Jun 2016 • 15 posts Report Reply

  • linger, in reply to krothville,

    Yep, that was exactly my point.

    Tokyo • Since Apr 2007 • 1930 posts Report Reply

  • Ian Dalziel,

    Walking at their side...
    I see John Key on some news programme (Sky News maybe) saying words to the effect of 'at the end of the day houses can be rebuilt' - while failing to say that if the Government does it, they make take a coupla goes to get it right, and make it an ordeal of another magnitude along the way.

    Still, it's nice to note Richie McCaw doing some helicopter work in the area - good to know he's still a safe pair of hands at the breakdown...

    Christchurch • Since Dec 2006 • 7944 posts Report Reply

  • Ian Dalziel,

    Attachment

    I also note that The Herald and TV1 news tonight both have trouble spelling Hanmer Springs correctly in captions and headings.
    'No ham in Hanmer and no sun in Sumner' - easy to remember!

    Christchurch • Since Dec 2006 • 7944 posts Report Reply

  • Russell Brown,

    So many people I know reported seeing the “earthquake lights” during the quake, and then Bryan Crump followed up with a bunch of people who’d reported the same to RNZ. So I thought I’d dig around a bit.

    Turns out everyone (including RNZ’s news team) forgot there were lights reported over Christchurch in 2011.

    And in 2014, there was a potential explanation offered in this paper.

    There is some scepticism that they exist at all, but that seems largely based on the quality and variety of reports.

    Well, there’s this now:

    Them there’s this more spectacular Twitter video.

    Someone I interact with fairly often on Twitter – and who is definitely not a nutter – says he saw a “red, blue, green bolt to the ground”, in Hastings.

    Auckland • Since Nov 2006 • 22834 posts Report Reply

  • izogi, in reply to Kiwiiano,

    A possible link between earthquakes and the phase of the moon & its tidal effects was one of the very first explanations for quakes, but it wasn't long before they could see no pattern in the distribution of the two events.

    My wife, who earned a geophysics PhD a few years back, was ranting about this particular story from NewsHub, which she decided must have largely misrepresented the GNS comments.

    Not to suggest that forces between the Earth and Moon have zero effect on earthquakes, but there's so much other stuff happening underground, which is almost entirely unknown, and also far more significant. Knowing where the Moon happens to be at any given time is effectively meaningless when it comes to trying to predict anything.

    I'm sure Mr Ring will be ready to take credit, though.

    Wellington • Since Jan 2007 • 1139 posts Report Reply

  • Hilary Stace, in reply to Russell Brown,

    Lots of reports after the Japanese earthquake too. Why can't it just be the flash from the release of a vast amount of energy? Seems very plausible to me.

    Wgtn • Since Jun 2008 • 3214 posts Report Reply

  • David Hood, in reply to izogi,

    which she decided must have largely misrepresented the GNS comments

    Part of the reason geologists can no longer completely dismiss it is that there was an article in nature a few months back that found a very mild statistical relationship with a few faults in Japan with a particular orientation to the moon. But this effect is so small as to make no difference to prediction. So there is now this easy to misinterpret area between "does it have anything to do with it" (which is a very broad "anything") and "does it have a measurable contribution" (is there anything useful we can measure). And that leaves a lot of room for dramatic reinterpretation.

    Dunedin • Since May 2007 • 1445 posts Report Reply

  • steven crawford, in reply to David Hood,

    Isn’t it more that there isn’t any known method of using what we know about the moons relationship to earth to predict earthquakes. Rather than that the moon has very little influence the earths earhquake activity?

    And there is little bit of newish silence here in this PDF heavy read, that’s interesting and remotely related to the ball lightning that’s being dissusted upthread. That’s only becouse it’s atmospheric particals being looked at, but there seems to be an atmospheric change preceding large earthquakes.

    Atlantis • Since Nov 2006 • 4414 posts Report Reply

  • Russell Brown, in reply to Ian Dalziel,

    I also note that The Herald and TV1 news tonight both have trouble spelling Hanmer Springs correctly in captions and headings.

    Yeah, we noticed that too. Arrgh.

    Auckland • Since Nov 2006 • 22834 posts Report Reply

  • Ian Dalziel,

    Attachment

    The Battle of the Bulge...
    I suspect there may well be some epiphenomenal connections with lunar and tidal cycles, especially around subduction zones - as the earth's magma is also affected by the tidal frequency, who's to say there aren't knock on effects when a bit of slack in the system caused by the passing bulge suddenly allows a large object to pass into the magma chamber, freeing up mass behind in a rush, releasing strain on a connected tectonic system. (see 1* and 2*)

    Much like the regular 'catch and release' that happens (in geological time) up the Kermadec Trench where a chain of undersea volcanoes are sucked under the Australian Plate (pic above) firing tsunamis and earthquakes towards the Bay of Plenty from time immemorial... (the chain gets gradually closer to NZ - so that is something to warn future generations about)

    Heck, look at the various tumbles and turns that Uluru/Ayers Rock took over millennia to get where it is, imagine something that large suddenly popping through into the molten zone...
    (see 3*)

    This is not to say every Super Moon or Full Moon (or close approach to the sun as well) will cause an earthquake, but they might always raise the odds and test a delicate system for confluences of geological events and other 'chinks in the armour'...


    see:
    1*: http://hvo.wr.usgs.gov/volcanowatch/archive/1998/98_05_28.html
    2*: http://phys.org/news/2014-01-moon-gravity-world-largest-tides.html
    3*:
    http://www.environment.gov.au/topics/national-parks/uluru-kata-tjuta-national-park/natural-environment/geology

    Christchurch • Since Dec 2006 • 7944 posts Report Reply

  • izogi,

    I'll happily submit to a consensus of geophysicists, but I think there needs to be much caution when discerning between "the Moon influences earthquakes" and "the Moon is any use for predicting earthquakes".

    Arguably me jumping up and down probably influences earthquakes (probably less than the Moon to be fair), but it's meaningless knowledge without knowing, understanding and measuring the far more significant influences of the tensions and states of things happening underground. Measuring that stuff is what geophysicists really struggle with right now.

    Wellington • Since Jan 2007 • 1139 posts Report Reply

  • Ian Dalziel, in reply to izogi,

    discerning between “the Moon influences earthquakes” and “the Moon is any use for predicting earthquakes”.

    Agreed...

    I was interested in this study of gravitational field anomalies prior to major earthquakes, detected by satellite.
    Detection of gravity changes before powerful earthquakes in GRACE satellite observations

    full pdf:
    http://www.annalsofgeophysics.eu/index.php/annals/article/view/6612/6394

    I read somewhere this and other realtime applications of it were hampered by lack of processing power and satellite access, imagine if some of or all of the Five Eyes type resources were diverted to proactive work rather than paranoia - I'd wouldn't be surprised the NSA's new supercomputers could correlate this data on the fly.

    Christchurch • Since Dec 2006 • 7944 posts Report Reply

  • Carol Stewart, in reply to Ian Dalziel,

    This is not to say every Super Moon or Full Moon (or close approach to the sun as well) will cause an earthquake, but they might always raise the odds and test a delicate system for confluences of geological events and other ‘chinks in the armour’…

    Mark Quigley and Brendan Duffy express it well:

    Small amplitude and large wavelength tidal deformations of the Earth due to motions of the sun and moon influence stresses in Earth’s lithosphere.

    It is possible that, for active faults that are imminently close to brittle failure, small tidal force perturbations could be enough to advance rupture relative to the earthquake cycle, or to allow a propagating rupture to travel further than it might otherwise have done.

    But the specific time, magnitude and location of this or any other large earthquake has not been successfully predicted in the short-term using tidal stresses or any other possible precursory phenomenon.

    Deliberately vague predictions that provide no specific information about the precise location and magnitude of a future earthquake are not predictions at all. Rather, these are hedged bets that get media air time due to the romantic misinterpretation that they were valid predictions.

    Most earthquake scientists, including those that research tidal triggering of earthquakes, highlight the importance of preparedness over attempts at prediction when it comes to public safety.

    Wellington • Since Jul 2008 • 825 posts Report Reply

  • David Hood,

    Another way of putting it, might be this.

    Lets arbitrarily say that, in a particular region, we expect 14 earthquakes of Mag 5 or greater in 1000 years. But when the moon is closest to the earth the risk goes up 7%. The moon is only closest to the earth for about 1/7th of the time (taking a bit of time either side) so of the 15 major quakes every 7000 years that we expectant times of a close moon, one of the quakes in that period might be expected not to have occurred at that time (but might have occurred at another time).

    It might be having an influence, but it is not very predictive.

    Dunedin • Since May 2007 • 1445 posts Report Reply

  • David Hood,

    That said, I've been involved in some interesting stuff recently involving using the gravitational response of sections of the crust to determine areas in a stressed state. So there is actual science around gravity and quakes, but the phase of the moon does not have much to offer for predictable causes.

    Dunedin • Since May 2007 • 1445 posts Report Reply

  • Carol Stewart, in reply to Prudence,

    It’s the lintel (150 to 200mm deep) spanning the distance above the door that offers protection. Some houses have door openings that are full height, (the height of the wall) in which case it will be the truss above the opening that provides support. A doorway is a good place to be in an earthquake.

    Actually, Prudence, the doorway advice is outdated. This is the latest from MCDEM:
    Are you wondering why we recommend "Drop, Cover and Hold" rather than getting under a doorway during an earthquake? The important thing is to lower you centre of gravity so you don't fall over (drop), make yourself a small target and protect your organs, head and neck (cover and hold). Doorways in modern houses are no stronger than other parts of the house and doors can swing and injure you. You can find out more here http://getthru.govt.nz/disasters/earthquake. Please share.

    Wellington • Since Jul 2008 • 825 posts Report Reply

  • David Hood, in reply to Carol Stewart,

    Actually, Prudence, the doorway advice is outdated

    When I was in central Christchurch in 2011 for the big one, my reflex action was to duck into the doorway I was standing beside, but with high glass in the corridor shattering and coming down, my thought was "No, I want to be under a table"

    Dunedin • Since May 2007 • 1445 posts Report Reply

  • Rosemary McDonald, in reply to Carol Stewart,

    the doorway advice is outdated

    Well, bugger.

    Plan A was to park Significant Other in his wheelchair in a doorway in the event of the Big One…. this is his own ‘self evac’ plan if by himself.

    Clearly we’ll have to go to Plan B…get wheelchair and person in it outside into the open, or Plan C…drag person out of wheelchair and drag his crippled arse under the table.

    Perhaps we should look into having some extra timbers installed to create a ‘lintelised’ zone.

    Waikato, or on the road • Since Apr 2014 • 1344 posts Report Reply

First ←Older Page 1 2 3 4 5 Newer→ Last

Post your response…

Please sign in using your Public Address credentials…

Login

You may also create an account or retrieve your password.