New Zealand earthquake: Tsunami follows powerful tremor(bbc.co.uk)
bbc.co.uk
New Zealand earthquake: Tsunami follows powerful tremor
http://www.bbc.co.uk/news/world-asia-37967178
162 comments
> I have 4 levels above me, hiding under a table
> wasn't going to do shit to save me [...] food
> has fallen off all the shelves,
Also, some tables, particularly heavy wooden and metal tables, can withstand lots and lots of weight. Hiding under them can help you avoid getting your skull bashed in by a falling slab of concrete.
The one biggish one I went through was in Seattle, where I was in a startup. We had cheap IKEA desks, which barely held the computers. I bolted for the door, which was the wrong thing to do in a brick clad building. Thankfully, we were on solid ground on Capitol Hill, not the fill in Pioneer Square, so I didn't get hit by falling cornice.
"You're doing it wrong," only for earthquakes.
Water pipes often accumulate a layer of sediment at the bottom. Anything that stirs it up will cause brief discolouration of the water. Your pipes may be fine. (That said, I wouldn't drink the water right now.)
You get the same thing if the Fire Department uses the hydrants, for real or just to test the system.
The usual advice is to boil the water if there is any doubt. For sediment, a coffee filter first wouldn't be a terrible idea.
Edit to add: immediately after an event, if you have a tank water heater, the water in the tank was already there. If you shut off the intake valve and turn off the heater, you have enough drinking water to last for a couple of weeks. Assuming you can get a container under the drain valve on the side. Triple check you have turned off the furnace before draining any significant amount water!
The usual advice is to boil the water if there is any doubt. For sediment, a coffee filter first wouldn't be a terrible idea.
Edit to add: immediately after an event, if you have a tank water heater, the water in the tank was already there. If you shut off the intake valve and turn off the heater, you have enough drinking water to last for a couple of weeks. Assuming you can get a container under the drain valve on the side. Triple check you have turned off the furnace before draining any significant amount water!
I'm pretty sure Civil Defence announced it's been contaminated. I would get bottled water, and get away from the coast if you're anywhere near there, or get to high ground. If you have no other option, go to a building with reinforced concrete that's high such as a parking lot. The Tsunami warning is issued to as far as wellington, and all of the cook straight.
If you are getting bottled water after an earthquake, you are already f*cked.
Have water on hand beforehand! It's not like bottles of water aren't for sale everywhere.
Have water on hand beforehand! It's not like bottles of water aren't for sale everywhere.
Yes, absolutely agreed. Last night's quake exposed my flat's somewhat chronic lack of preparation. I'll be visiting the supermarket tonight and ensuring our insurance policies are up to date, as I imagine much of Chch will be.
We've got a small collection of life straws/survival supplies for tramping, which is good, but they're in a part of the house that'd be inaccessible in a major event :/.
We've got a small collection of life straws/survival supplies for tramping, which is good, but they're in a part of the house that'd be inaccessible in a major event :/.
Stay safe and good luck.
Or, if you live near massive amounts of fresh water, stock up on high grade water filters, and have buckets or many bottles.
Given what ChCh went through, I really hope Wellington takes quake-proofing its more risk-prone buildings seriously. I say that every time an earthquake causes damage there, but still the building owners ask for more time and the council gives it.
A lot more buildings in Wellington are on isolaters. Parliament was retrofitted with them (huge saws cut through the concrete foundation where they were then installed). TePapa has a thing outside the museum where you can go down and see some of them.
Yeah Wellington has always taken it seriously, I remember the building where I worked in 2002 had a sticker on it by the council saying the building wasn't earthquake safe. The buildings here are much more earthquake safe than Christchurch but also the damage potential is much higher.
> Yeah Wellington has always taken it seriously,
Only sort of. We have the whole dynamic of pushing out the date buildings are supposed to be meeting requirements, and dodgy engineers signing off on buildings that are below target NBS.
Only sort of. We have the whole dynamic of pushing out the date buildings are supposed to be meeting requirements, and dodgy engineers signing off on buildings that are below target NBS.
Dodgy engineers aren't going to sign off on anything because they are liable for manslaughter in the case of a catastrophe. I used to work for a structural engineering company and had to present evidence at the Royal Commission of Inquiry, engineers (at least all the ones I know) take this very seriously.
Most of the out of date buildings are empty, there are still a few empty buildings around Wellington because they don't meet code.
Most of the out of date buildings are empty, there are still a few empty buildings around Wellington because they don't meet code.
As far as pushing out the dates, buildings with a big sticker on them saying they are unsafe tend to struggle to find tenants, and when they do the rent has to be very cheap, so most building owners either sell the buildings or strengthen them.
And that's why the property owners have been lobbying the councils to hold off on those big stickers - because then how could they afford to do the work that they'll totally do, within X years, if the rents drop?
That's what I'm referring to, yeah.
Great. Do you have a pic of the sticker? I'm moving to Umbria, Italy...
No, it was a while ago. But a google image search showed up one of the ones that they used in Christchurch.
http://3.bp.blogspot.com/-Ncu7cINaZiE/TtGHnDoH72I/AAAAAAAAAS...
http://3.bp.blogspot.com/-Ncu7cINaZiE/TtGHnDoH72I/AAAAAAAAAS...
Thanks.
http://www.radionz.co.nz/assets/news/18382/eight_col_xlarge_...
That's the yellow sticker that buildings in Wellington get if they're unsafe but still usable.
That's the yellow sticker that buildings in Wellington get if they're unsafe but still usable.
Advice in Japan is stay inside. They claim running outside during an earthquake your more likely to get hit by falling glass and other debris
You're 500km north of epicentre and felt that. Im 150km south of epicentre and felt nothing.
Wellington isn't 500km away :)
It looks like the quoted epicentre was just the start point of the rupture that headed off to the northeast. Which explains why the shaking seemed worse to the north and why so much activity seems to be recorded from the Seddon area again:
http://earthquake.usgs.gov/earthquakes/eventpage/us1000778i#...
In Wellington it seemed like the first half was just a gentle swaying before it really kicked in for the second half. That was probably the rupture moving closer.
I found this really interesting: The USGS talks about quakes of this magnitude usually have a wide scale area of slippage eg they've modelled 200x60 km for this one:
http://earthquake.usgs.gov/earthquakes/eventpage/us1000778i#... http://earthquake.usgs.gov/earthquakes/eventpage/us1000778i#...
It looks like the quoted epicentre was just the start point of the rupture that headed off to the northeast. Which explains why the shaking seemed worse to the north and why so much activity seems to be recorded from the Seddon area again:
http://earthquake.usgs.gov/earthquakes/eventpage/us1000778i#...
In Wellington it seemed like the first half was just a gentle swaying before it really kicked in for the second half. That was probably the rupture moving closer.
I found this really interesting: The USGS talks about quakes of this magnitude usually have a wide scale area of slippage eg they've modelled 200x60 km for this one:
http://earthquake.usgs.gov/earthquakes/eventpage/us1000778i#... http://earthquake.usgs.gov/earthquakes/eventpage/us1000778i#...
We even felt it up in Auckland. It woke my partner and I up and made the building creak and flex a bit.
Currently in Wellington. Was fucking shaky, seriously thought the building was about to collapse. This was ~500 km from the epicenter.
~200km?
Also in Wellington, and it's work from home day today here while engineers check the building for damage.
~200km?
Also in Wellington, and it's work from home day today here while engineers check the building for damage.
[deleted]
Description on Twitter: "The shaking went on for ages, longest quake I've felt. It was like waiting for a Verge article to finish loading."
https://twitter.com/thefoehesought/status/797814348672421888
https://twitter.com/thefoehesought/status/797814348672421888
For context there was about 2mins of shaking :)
The longest quake I've ever felt too. Some seismologists are speculating that it might actually have been two distinct quakes happening at roughly the same time.
The longest quake I've ever felt too. Some seismologists are speculating that it might actually have been two distinct quakes happening at roughly the same time.
Brilliant, too bad he didn't say Forbes. That would be more accurate.
Meh, forbes is more a problem with those pesky pre-load screens. The Verge site is a massive heap of dung even after loading. I swear every image is loaded as RAWs and then converted via JS into something edible by the browser, or some other "hipster artistry".
Magnitude 7.5 earthquake. For reference, I felt this in Hamilton, a bit under 1,000 KM away. First earthquake I have ever felt. Hamilton never, ever gets earthquakes.
Nevertheless, NZ infrastructure is built to withstand this sort of stuff. Only $100m-1b economic damage is expected, no casualties expected.
Nevertheless, NZ infrastructure is built to withstand this sort of stuff. Only $100m-1b economic damage is expected, no casualties expected.
The problem with earthquakes is that damage accumulates. So while a building might stay intact or with minor damages during the main one, the aftershocks could wreck havoc. And with an 7.8 aftershocks could last for months and be quite severe.
Nevertheless I hope everyone is OK and wish you the best. I've experienced quite a few earthquakes in my life, although nothing over 7, and the shock stays for long. It's one of those times in your life when you feel completely helpless.
Nevertheless I hope everyone is OK and wish you the best. I've experienced quite a few earthquakes in my life, although nothing over 7, and the shock stays for long. It's one of those times in your life when you feel completely helpless.
Yes but all multi Tennant buildings and large buildings will be inspected. We're pretty used to this and have some of thebest earthquake engineers in the world.
USGS is indicating 7.8.
NZ's Geonet and USGS use different versions of the Richter scale, so both are likely correct.
> Nevertheless, NZ infrastructure is built to withstand this sort of stuff
Building maybe. But our main transportation routes often have little redundancy and go through some potentially hazardous areas. State Highway 1 down the Kaikoura coast is a great example. Hopefully Lewis Pass survived ok.
Building maybe. But our main transportation routes often have little redundancy and go through some potentially hazardous areas. State Highway 1 down the Kaikoura coast is a great example. Hopefully Lewis Pass survived ok.
Better resolution map: https://pbs.twimg.com/media/CxJjRotUUAAJK-w.jpg:large (from https://twitter.com/NZcivildefence/status/797809307597213696)
Some tweets with photos:
https://twitter.com/ThomasMeadia/status/797806928520880128
https://twitter.com/ThomasMeadia/status/797809032635420672
https://twitter.com/HenryMcMullan/status/797813785461334017
Some tweets with photos:
https://twitter.com/ThomasMeadia/status/797806928520880128
https://twitter.com/ThomasMeadia/status/797809032635420672
https://twitter.com/HenryMcMullan/status/797813785461334017
I'm from Christchurch, contacted family there. There's been mass evacuations from the coastline. Tsunami's have started but they can last for hours. Kaikoura has already had a a surge measured 2.5m, if this is the case the waves will get worse before they get better. But NZ is pretty prepared for these things, so hopefully everyone scampers to the safe distance from the coastline. I worry about the Chatham Islands, they're directly east of the epicentre, and Tsunami's travel very fast. I hope they've all gotten to high ground.
No, that 2.5m high one was the worst of the waves.
http://images.geonet.org.nz/tsunami/plots/latest/detide.png
It was most likely caused by a movement of sediment into the Hikurangi Trough.
It was most likely caused by a movement of sediment into the Hikurangi Trough.
That would make a lot of sense. Civil defence must be being pessimistic in there predictions, as you should be. It's better to be away from a coastline if there might be a tsunami and there isn't, then the other way way around.
Then why is it still reported that waves 3-5 meters are expected?
Civil Defence are doing their job, getting people away from the coastline. There maybe Tsunami's there may not be, better not to take any risks. Must be protocol when any of the Tsunami alarms are triggered.
Also because your coastline can fundamentally change how it affects you - the gauges near Christchurch measured 0.5m appx at the highest, whereas an (empty, thank goodness) house at the end of a funnel shaped bay in the same vicinity got hit by an estimated 2 - 3m wave.
Isn't Christchurch still finishing the rebuild from the last big quake?
Anyone know what the lights were about? http://www.newshub.co.nz/nznews/strange-lights-during-earthq... or is it a hoax.
I'm in Palmerston North a long way away, but that was the biggest quake I've felt.
I'm in Palmerston North a long way away, but that was the biggest quake I've felt.
My curtain fell down, and I saw some impressive green flashes across wellington harbour, near Seaview.
General consensus is something to do with the power grid.
General consensus is something to do with the power grid.
link to video https://www.youtube.com/watch?v=1hIQaJg3lVM
News report and another video:
http://i.stuff.co.nz/national/86420960/earthquake-strange-gl...
http://i.stuff.co.nz/national/86420960/earthquake-strange-gl...
I was just reading this today on Wikipedia: "No evidence has been found of any correlation between supermoons with major earthquakes."
Well yes, because a supermoon is just when the moon being close to the earth happens to line up with the moon being full. The moon comes this close to the earth once a month.
I'm from Christchurch which is about 100km away. Felt like a long rocking boat ride. Luckily it wasn't violent, unlike our 6.3 quake in 2011 which accelerated the city vertical by a foot, dumped it down and smashed everything.
Had to laugh, consoled my daughter on the phone from here in the South Island last night and said "See, trumps been in 3 days now and the world hasnt ended yet" and at midnight it sure felt like it had!
At the risk of sounding pedantic, he doesn't take office until Inauguration Day on January 20.
Here a link to the list of recent earthquakes: http://www.geonet.org.nz/quakes/felt/severe
Another link: http://www.emsc-csem.org/. Initially showing a map of Europe, it provides however, a global list with location and intensity in tabular form.
I am in Hanmer Spring on holiday with the kids. Was 15km from the Epicenter when it hit. Big shake for a long time. One of the kids didn't wake up... worst thing that happened in our house was the shampoo falling into the bath, so pretty blessed there. All roads closed so guess we have an extended holiday. Lots of very big after shocks.
Could there be any connection to the moon's current proximity to Earth? Does anyone know to what extent the moon's gravity can influence earthquakes? Tides are one thing, but it seems plausible that the moon being closer to earth than it has been in 68 years could be moving the plates a bit more than usual.
There was a seismologist talking about that this morning. There is an effect that correlates with lunar cycles, but it is a very faint signal in a lot of random noise.
So it might cause some faults that are about to rupture to release a bit earlier than otherwise, but it's not a useful predictor of anything.
So it might cause some faults that are about to rupture to release a bit earlier than otherwise, but it's not a useful predictor of anything.
In general, there is a connection. The earth tides have an amplitude in the tens of centimeters [1] (yes, the earth moves under our feet!) and a connection to earthquakes is a given, since the stress changes on faults can trigger them. Here is one example: [2] Their research also indicates that a higher stress can trigger earthquakes not triggered by lower stress since the local fault strength must be exceeded.
[1] https://en.wikipedia.org/wiki/Earth_tide
[2] http://www.pnas.org/content/113/31/8601.abstract
[1] https://en.wikipedia.org/wiki/Earth_tide
[2] http://www.pnas.org/content/113/31/8601.abstract
GNS scientists are saying there's no connection.
If fracking causes earthquakes (perhaps thats a big if) then a satellite that shifts billions of metric tonnes of water around the planet on a daily basis must surely have an impact.
Can someone please edit the title?
And wow, this looks heavy. I hope everyone is well.
And wow, this looks heavy. I hope everyone is well.
There's that word again. "Heavy." Why are things so heavy in the future? Is there a problem with the Earth's gravitational pull?
It's surfer slang, elements of which have made their way into a lot of the English spoken in NZ, Oz and SA.
He is quoting the movie "Back to the Future"
http://www.imdb.com/title/tt0088763/quotes?item=qt0416301
http://www.imdb.com/title/tt0088763/quotes?item=qt0416301
It doesn't matter, it's not appropriate when people are trapped under collapsed buildings and are dead.
You seem to know something that others don't. What's your source on that?
I was part of the first response for the Christchurch earthquake providing technical support and co-workers in my old job are trained USAR engineers that were deployed overnight. But most of this information is from the NZ media. We aren't talking high fatalities, but USAR are looking for a couple of missing people and there are buildings that have collapsed, people were also stuck under a vat in a winery and had to be cut out. There are two people dead but not much information is coming out of the most effected area because most communications are down.
English is not my first language, so what exactly is the problem here? Please explain.
The poster used slang to reference the event and someone else was making fun of the slang by taking it literally, completely trivialising the fact that a huge natural disaster occurred which resulted in death, injury, and hundreds of millions if not billions of dollars in damage.
I _am_ that poster. English is my second language and I wasn't aware that the word heavy is perceived as slang. I should've used "serious".
No, you're fine. It was just the reply seemed a little inappropriate.
cloudjacker(1)
I don't think it comes from surfing.
It's British (probably Commonwealth) English for serious or important. See usage 6: https://en.oxforddictionaries.com/definition/heavy (unfortunately, no dates given on the quotes).
This lists the usage meaning "severe" as from 1849: http://historicalthesaurus.arts.gla.ac.uk/category/?id=15861...
It's British (probably Commonwealth) English for serious or important. See usage 6: https://en.oxforddictionaries.com/definition/heavy (unfortunately, no dates given on the quotes).
This lists the usage meaning "severe" as from 1849: http://historicalthesaurus.arts.gla.ac.uk/category/?id=15861...
Surfer here from Australia, "heavy" is very common surfer slang used to describe something "serious" or "unpleasant".
It comes from the idea of a "heavy wipe-out", which can quite easily occur while surfing "waves of consequence". Generally good, hollow, barrelling waves contain more water volume and energy, when they break they look and feel "heavier" and while being better rides, have more potential to injure a surfer. The slang has indeed made it's way into everyday usages in NZ and Oz and Hawaii, I guess California also.
I believe the original poster is describing a serious or unpleasant situation, which seems to be the case.
It comes from the idea of a "heavy wipe-out", which can quite easily occur while surfing "waves of consequence". Generally good, hollow, barrelling waves contain more water volume and energy, when they break they look and feel "heavier" and while being better rides, have more potential to injure a surfer. The slang has indeed made it's way into everyday usages in NZ and Oz and Hawaii, I guess California also.
I believe the original poster is describing a serious or unpleasant situation, which seems to be the case.
According to their profile, the author of the post is a native German speaker. In German, the same word ("schwer") means both "heavy" and "difficult" or "serious" (in the sense that somebody in such a situation is carrying a heavy burden). The literal translation would be "heavy".
English is a Germanic language, so perhaps in a sense this meaning has always been part of it. As you point out, even if it's not considered completely idiomatic most people would have no trouble interpreting the meaning.
English is a Germanic language, so perhaps in a sense this meaning has always been part of it. As you point out, even if it's not considered completely idiomatic most people would have no trouble interpreting the meaning.
[deleted]
People are dead and trapped under collapsed buildings in Kaikora and this is what upsets you?
If each of us bore all the suffering in the world at once, we'd never get anywhere.
You've inserted yourself in a conversation occurring a tremendous distance from the events, and it's not like the comment was even making light of the situation.
You've inserted yourself in a conversation occurring a tremendous distance from the events, and it's not like the comment was even making light of the situation.
The internet is global you realise that right? People who are on here are experiencing and have experienced these events, don't assume that everyone is based in the US. They may even have had loved ones missing at the point that this conversation was happening.
And it was a conversation about a disaster as it was happening in complete real time, one which resulted in a loss of life, displaced families, and hundreds of millions if not billions of dollars worth of damage. It wasn't a past event which can be trivialised, it was being trivialised as people were being pulled from the rubble of their homes and workplaces.
This particular conversation was occurring between people, some of whom were far away from the events and some of whom were being shaken as they typed.
And it was a conversation about a disaster as it was happening in complete real time, one which resulted in a loss of life, displaced families, and hundreds of millions if not billions of dollars worth of damage. It wasn't a past event which can be trivialised, it was being trivialised as people were being pulled from the rubble of their homes and workplaces.
This particular conversation was occurring between people, some of whom were far away from the events and some of whom were being shaken as they typed.
I probably over-reacted but it's obvious that people living through an event like this are going to be emotional, we had no sleep and people we knew were missing.
I also have prior experience with disasters, I provided technical support to the engineers in the NZ Urban Search and Rescue teams in Christchurch, and saw the devastation first hand as I was setting up remote offices within the red-zone and rescuing computer equipment from buildings that were missing walls. I also saw people working frantically to extract survivors from collapsed buildings as we went by. I lived in the same house and often shared rooms with those engineers that were doing the rescuing work, and I saw the harried expressions on their faces every day.
So I reserve the right to ask people to respect the situation at hand.
I also have prior experience with disasters, I provided technical support to the engineers in the NZ Urban Search and Rescue teams in Christchurch, and saw the devastation first hand as I was setting up remote offices within the red-zone and rescuing computer equipment from buildings that were missing walls. I also saw people working frantically to extract survivors from collapsed buildings as we went by. I lived in the same house and often shared rooms with those engineers that were doing the rescuing work, and I saw the harried expressions on their faces every day.
So I reserve the right to ask people to respect the situation at hand.
"Tremor"? I mean, IMO anything 7+ is more than a tremor.
Can I just say — stoked to see all the kiwis on HN!
Unfortunately the "Latest Felt Quakes Map" at http://www.weatherwatch.co.nz/geonet doesn't work because the website has exceeded 25,000 map loads in a day.
That page is just an inferior version of the source: https://www.geonet.org.nz/quakes/felt
Or try geonet.org.nz itself.
USGS page on the quake: http://earthquake.usgs.gov/earthquakes/eventpage/us1000778i#...
Try this one:
http://www.emsc-csem.org/Earthquake/
Do we expect to see this wave on the other side of the Tasman? And if so, will it be big?
Unlikely because the earthquakes were on the East coast of New Zealand, away from Australia.
[deleted]
Cross-posting from my FB feed:
Here's some of the interesting stuff I've found on the internet about today's earthquake (that they're now calling a 7.8):
1) real-time Buoy data, for helping to determine the likelihood of a Tsunami: http://www.ndbc.noaa.gov/ Interestingly, the quake only caused a tiny change in the sea level (in the region of 5 cm's) but the expected swells on land are in the region of 3-5 meters. I believe this is because as the wave gets closer to land, it get's funneled into a smaller area, meaning the 5cm change in sea level gets amplified. Which is why it's hard for the civil service to accurately predict whether a tsunami is likely when these events occur (That, and the nearest working buoy is in Tonga), which would by why they almost always say yes, and then retract the warning later.
2) the USGS science-y explanation for what actually happened. The take-away seems to be that this may have increased the stress on the primary fault in NZ. Interestingly, their's a a suggestion that the rupture was across the hope fault, rather than along it, which helps to explain why the after shocks have been so varied (by location): http://earthquake.usgs.gov/earthquakes/eventpage/us1000778i#...
3) also from USGS, a map indicating affected regions, with town populations, and the likely economic impact of the quake: http://earthquake.usgs.gov/earthquakes/eventpage/us1000778i#...
4) The Canterbury Police shared a link earlier that indicated 3-5 meter swells is around the maximum we should expect from a locally generated earthquake (due to the nature of fault lines in NZ), that's not to say we can't experience a larger tsunami, but that said tsunami would have to be generated externally (like say, south america), which should in theory give us more time to prepare. But like all things, this isn't a hard and fast rule.
5) there's a pretty cool video of what purports to be lights in the sky over wellington during the earthquake (probably has something to do with magnetic interference from the energy released by the quake): https://www.facebook.com/plugins/video.php?href=https%3A%2F%...
6) stuff have had pretty good live coverage here: http://www.stuff.co.nz/national/86416304/live-north-canterbu...
7) The USGS website indicated that the quake lasted around 2 minutes, with the highest intensity coming around 50 seconds into the quake.
Here's some of the interesting stuff I've found on the internet about today's earthquake (that they're now calling a 7.8):
1) real-time Buoy data, for helping to determine the likelihood of a Tsunami: http://www.ndbc.noaa.gov/ Interestingly, the quake only caused a tiny change in the sea level (in the region of 5 cm's) but the expected swells on land are in the region of 3-5 meters. I believe this is because as the wave gets closer to land, it get's funneled into a smaller area, meaning the 5cm change in sea level gets amplified. Which is why it's hard for the civil service to accurately predict whether a tsunami is likely when these events occur (That, and the nearest working buoy is in Tonga), which would by why they almost always say yes, and then retract the warning later.
2) the USGS science-y explanation for what actually happened. The take-away seems to be that this may have increased the stress on the primary fault in NZ. Interestingly, their's a a suggestion that the rupture was across the hope fault, rather than along it, which helps to explain why the after shocks have been so varied (by location): http://earthquake.usgs.gov/earthquakes/eventpage/us1000778i#...
3) also from USGS, a map indicating affected regions, with town populations, and the likely economic impact of the quake: http://earthquake.usgs.gov/earthquakes/eventpage/us1000778i#...
4) The Canterbury Police shared a link earlier that indicated 3-5 meter swells is around the maximum we should expect from a locally generated earthquake (due to the nature of fault lines in NZ), that's not to say we can't experience a larger tsunami, but that said tsunami would have to be generated externally (like say, south america), which should in theory give us more time to prepare. But like all things, this isn't a hard and fast rule.
5) there's a pretty cool video of what purports to be lights in the sky over wellington during the earthquake (probably has something to do with magnetic interference from the energy released by the quake): https://www.facebook.com/plugins/video.php?href=https%3A%2F%...
6) stuff have had pretty good live coverage here: http://www.stuff.co.nz/national/86416304/live-north-canterbu...
7) The USGS website indicated that the quake lasted around 2 minutes, with the highest intensity coming around 50 seconds into the quake.
There are some videos on Youtube of tsunami from various places.
Here's one from Japan: https://www.youtube.com/watch?v=j0YOXVlPUu4
https://www.youtube.com/watch?v=5IKIazZc-a8
It doesn't look like much is happening at the beginning. It doesn't look like a wave, or a front of water. But it's a lot of water, and it's fast.
Here's one from Japan: https://www.youtube.com/watch?v=j0YOXVlPUu4
https://www.youtube.com/watch?v=5IKIazZc-a8
It doesn't look like much is happening at the beginning. It doesn't look like a wave, or a front of water. But it's a lot of water, and it's fast.
1) I think it was because the 5cm height is backed by a huge width, when crawling towards the land slope creates a very strong (not necessary high) wave that just keeps pushing forward.
Tsunami waves have an extremely long period. A good surfing wave forms when a swell 2-5 m amplitude with period 13-24s when it starts to feel the bottom of the ocean.
The amplitude of the tsunami wave in the open ocean is much smaller than wind-generated swells but they can have periods of 60-70 minutes so they are more of a surge that just keeps coming when they hit land, and as you say when they start to feel the bottom they stand up and the large volume of water in the wave makes it stand up larger and more powerful than you would expect for a smaller amplitude swell.
Every wave has a peak and a trough and the trough of the tsunami wave is what causes the water levels to recede so drastically before the wave hits.
Geographic features like valleys that get narrower and narrower will cause the same volume of water hitting the coast to make a much more drastic change in water level
The amplitude of the tsunami wave in the open ocean is much smaller than wind-generated swells but they can have periods of 60-70 minutes so they are more of a surge that just keeps coming when they hit land, and as you say when they start to feel the bottom they stand up and the large volume of water in the wave makes it stand up larger and more powerful than you would expect for a smaller amplitude swell.
Every wave has a peak and a trough and the trough of the tsunami wave is what causes the water levels to recede so drastically before the wave hits.
Geographic features like valleys that get narrower and narrower will cause the same volume of water hitting the coast to make a much more drastic change in water level
Imagine the energy stored by lifting a kilometre-high column of water 5cm. Now imagine how high that energy can lift a 5m column of water once it reaches the coast. Obviously there is the 1/r dissipation because the circumference increases, but still, deep water lifts like this can cause a massive surge at the coast.
Not 100% applicable to New Zealand but here's the Tokyo disaster prepardness book --
http://www.metro.tokyo.jp/ENGLISH/GUIDE/BOSAI/
It has a lot of good practical information -- especially chapters 1 & 4. We all got one sent to our homes, and I thought it was quite useful!
http://www.metro.tokyo.jp/ENGLISH/GUIDE/BOSAI/
It has a lot of good practical information -- especially chapters 1 & 4. We all got one sent to our homes, and I thought it was quite useful!
Good on this guy for getting the warning out early, 7.2 or greater and potential for a tidal wave, spot on old chap! https://www.youtube.com/watch?v=isl1Gtg74e4
When I was a kid, the 1992 Big Bear Landers earthquake hit in Southern California. That was a 7.6 if I recall. So I can relate to what those in NZ are feeling. Our rock chimney collapsed and fell off the house, nearly crushing my mom who was outside at the time.
Parts of the South Island have moved 2 metres closer to the north. That's a big shunt.
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Does anybody know the status of RocketLab's facilities [1]?
[1] https://rocketlabusa.com/rocket-lab-launch-complex-1-ready-f...
[1] https://rocketlabusa.com/rocket-lab-launch-complex-1-ready-f...
Oh those are well up the North Island, they probably didn't even feel it there. Or if they did, it would have been very mild.
They do have employees in the South Island too (mainly Christchurch), and were looking at Birdling's Flat as a launch site. However, I imagine anyone involved in the South will also be fine -- Christchurch rolled around but didn't suffer much damage.
Yeah my father is in Rotorua and didn't feel it, I'm sure rocketlab are fine.
Does anyone know if there is any special effort to construct buildings that can withstand reasonable earthquakes in New Zealand?
Christchurch seems particularly prone to quakes in New Zealand. I hope the people of New Zealand are safe.
Christchurch seems particularly prone to quakes in New Zealand. I hope the people of New Zealand are safe.
Nearly 2/3rds of the casualties from the 2011 earthquake were a single building that contained an ESL school, a nursing school, and a clinic - and the construction supervisor of that building wasn't actually an engineer, but had stolen a retired engineer's identity.
https://en.wikipedia.org/wiki/CTV_Building
https://en.wikipedia.org/wiki/CTV_Building
We have fairly comprehensive building regulations for all new housing. Our new house plans were rejected because we didn't specify strong enough straps to fix the hot water cylinder to the wall. The straps they insisted on would withstand 10 times the force experienced in the Christchurch earthquake, which was one of the most violent in terms of acceleration ever. When the big one happens, our house may be destroyed but by god the hot water cylinder will still be attached to the wall!
New Zealand in general is very quake-prone - our nickname in Victorian times was "the shaky isles". In fact our country owes it's existence to a particularly nasty intersection between the Australian and Pacific plates, with the Aussie plate slipping under the Pacific in the South Island, and vice versa in the North Island. You might think that the bit in the middle would be particularly dangerous, and you'd be right. Now guess where we built Wellington, our capital city?
Finally, there was a nice anecdote about some US hotel guests standing in the cold and dark after being evacuated from their damaged hotel. Asked if this had changed their mind about moving to NZ, they replied "Hell no, Trump is a far worse disaster than this!".
New Zealand in general is very quake-prone - our nickname in Victorian times was "the shaky isles". In fact our country owes it's existence to a particularly nasty intersection between the Australian and Pacific plates, with the Aussie plate slipping under the Pacific in the South Island, and vice versa in the North Island. You might think that the bit in the middle would be particularly dangerous, and you'd be right. Now guess where we built Wellington, our capital city?
Finally, there was a nice anecdote about some US hotel guests standing in the cold and dark after being evacuated from their damaged hotel. Asked if this had changed their mind about moving to NZ, they replied "Hell no, Trump is a far worse disaster than this!".
Yes, there are earthquake standards for new buildings, and mandatory retrofitting for older buildings (as they are updated).
From what I've seen, this is pretty similar to San Francisco. It would be interesting to see data comparing the standards across earthquake-prone countries/regions.
From what I've seen, this is pretty similar to San Francisco. It would be interesting to see data comparing the standards across earthquake-prone countries/regions.
I used to work for a structural engineering company that had offices in both NZ and California, from what I understand the standards of earthquake engineering in NZ are higher than in California.
To be honest I think you're probably safer in a large earthquake in a post Christchurch NZ than in a small earthquake in a country that doesn't usually get them.
To be honest I think you're probably safer in a large earthquake in a post Christchurch NZ than in a small earthquake in a country that doesn't usually get them.
Christchurch is actually not on the fault line, and it was a surprise when such a severe earthquake hit in 2011, so they weren't well prepared. All the susceptible buildings collapsed then, and new buildings are earthquake-proof.
A big problem in the Christchurch region is liquefaction. There's not much earthquake codes can do to keep the ground from turning to goop.
It wasn't liquefaction that killed people though. That is what removed a large portion of the housing stock in the east, however.
You're completely right. Earthquake codes save lives, but in liquefaction zones, the structures may be unlivable afterwards even if they're completely intact.
The point of earthquake codes is not that the buildings are livable in afterwards, in fact in Christchurch something like 30% of all buildings had to be demolished. The point is that they stay up long enough for rescuers to get in, and if they do collapse they collapse with survival cells rather than pancake. In Christchurch the buildings performed very well with exception of the CTV building which pancaked. Although I know that a few buildings were only seconds away from collapsing so we were very lucky.
Don't forget the PGG building... and all the unsecured facades that collapsed onto streets killing people, a risk known about since the 90s.
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Damn that is really scary. I used to work in Miramar (Wellington suburbs), which is built on reclaimed sea, if I recall, and everyone was freaked out that a major earthquake would liquify the entire area.
Huh? Miramar is a steep hilly peninsular. Are you talking about Rongotai?
The flat bit in the middle that is most of the Miramar suburb is seabed (and later swamp) that has been uplifted by large earthquakes over time.
TIL. Born and raised in Wellington city and never knew that.
Really wish the best to all the people impacted here, stay safe!
Hoping all are safe and stay safe in New Zealand!
Anyone know of a group or website which is tracking the incidence and intensity of earthquakes over time?
http://www.globalcmt.org/
Scroll to the bottom and look at the chart of cumulative energy (moment) release over time. This is probably the easiest visualization what you're looking for without going to scientific papers. It only goes back to the 1970s though. The big steps are the Sumatran earthquakes and Tohoku (Japan). There were some equally big steps in the 1950s.
As far as I know (and I do this professionally) there is no evidence for any real variation in the global, time-averaged rate of earthquake occurrence or energy release. However the time window to average over has to be several decades to centuries depending on how comfortable one is with noise. Any individual segment of a fault will have an earthquake repeat time (for a significant earthquake) of hundreds (San Andreas fault) to tens of thousands of years, and is lots of evidence for clusters of earthquakes on individual faults or sets of faults, but this is mostly a local effect--the stress changes in the crust caused by an earthquake can basically load nearby faults and affect when they will have the next earthquake. But again, this is for the most part local (<100 km). Globally, earthquakes are essentially unrelated. That a big one may hit Chile and then Japan in short order is happenstance as far as the seismological community is concerned (though it's not dogma, and long-distance 'teleseismic' triggering is investigated--it just doesn't seem to be a big deal).
However, earthquakes in the news aren't a good reflection of global seismic statistics. Earthquakes like the Italian events (M6-6.6) over the past few months (and years) occur every day, but mostly in the ocean basins and don't affect people other than shaking some palm thatch roofs in Vanuatu. The most deadly event (minus tsunami) in my lifetime was the Haiti earthquake in 2010, killing ~200,000 people, and it was a pretty routine, moderate-magnitude event. It just hit an incredibly vulnerable population.
Scroll to the bottom and look at the chart of cumulative energy (moment) release over time. This is probably the easiest visualization what you're looking for without going to scientific papers. It only goes back to the 1970s though. The big steps are the Sumatran earthquakes and Tohoku (Japan). There were some equally big steps in the 1950s.
As far as I know (and I do this professionally) there is no evidence for any real variation in the global, time-averaged rate of earthquake occurrence or energy release. However the time window to average over has to be several decades to centuries depending on how comfortable one is with noise. Any individual segment of a fault will have an earthquake repeat time (for a significant earthquake) of hundreds (San Andreas fault) to tens of thousands of years, and is lots of evidence for clusters of earthquakes on individual faults or sets of faults, but this is mostly a local effect--the stress changes in the crust caused by an earthquake can basically load nearby faults and affect when they will have the next earthquake. But again, this is for the most part local (<100 km). Globally, earthquakes are essentially unrelated. That a big one may hit Chile and then Japan in short order is happenstance as far as the seismological community is concerned (though it's not dogma, and long-distance 'teleseismic' triggering is investigated--it just doesn't seem to be a big deal).
However, earthquakes in the news aren't a good reflection of global seismic statistics. Earthquakes like the Italian events (M6-6.6) over the past few months (and years) occur every day, but mostly in the ocean basins and don't affect people other than shaking some palm thatch roofs in Vanuatu. The most deadly event (minus tsunami) in my lifetime was the Haiti earthquake in 2010, killing ~200,000 people, and it was a pretty routine, moderate-magnitude event. It just hit an incredibly vulnerable population.
You're the real MVP. Thanks for your understanding of my question and the info. I get what you're saying about cumulative energy release over time and it's interesting to note the effect that earthquakes' periodicity has on how we need to sample the data. Very useful.
Not sure if suitable for your purposes, but GeoNet. They use a network of digital seismic stations. Whenever seismic waves propagate, doing a time-analysis of when they passed under each station can tell you where the quake occurred. This is augmented with crowd-sourced "felt reports".
Literally within seconds of a shake, the preliminary report hits their website, and its confidence level increases over the next few minutes as more data reports in.
I believe their online (open) data set now catalogs all NZ-region earthquake events from like the last 80 years or something. Pretty neat.
Here is the page for the big one of 6 hours ago, not to be confused with the dozens of also-large aftershocks following it:
https://www.geonet.org.nz/quakes/region/newzealand/2016p8580...
Literally within seconds of a shake, the preliminary report hits their website, and its confidence level increases over the next few minutes as more data reports in.
I believe their online (open) data set now catalogs all NZ-region earthquake events from like the last 80 years or something. Pretty neat.
Here is the page for the big one of 6 hours ago, not to be confused with the dozens of also-large aftershocks following it:
https://www.geonet.org.nz/quakes/region/newzealand/2016p8580...
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I'm more looking for a study that tracks an increase or decrease in their intensity and magnitude over time. I would need to scientifically study and analyze the data at the link you kindly shared in order to see that.
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So the tsunami was 1 foot Hawaian style. Doesn't seem too big...
Less a wave, and more a rapid increase in sea level lasting for a few minutes.
tsunami wave != typical wave. A wall of water that just keeps coming. A water bulldozer.
The tsunami risk was low because it was an inland quake, however they enacted a tsunami evacuation as a precaution. Would you rather they take a risk?
Oh, for sure, of course I would! That is exactly what I meant by my comment.
yeah but the period is 60 minutes
Videos of the earthquake:
https://youtu.be/WcljQHCUm_o?t=20
https://youtu.be/EsnS28ulJUw
News say it's 7.4 - 7.8 magnitude.
https://youtu.be/WcljQHCUm_o?t=20
https://youtu.be/EsnS28ulJUw
News say it's 7.4 - 7.8 magnitude.
Hmm, I doubt that these videos are the NZ quake. It happened at around midnight, and those videos are in broad daylight.
EDIT: I see others have already corrected this misinformation.
EDIT: I see others have already corrected this misinformation.
Those videos look like the earthquake that destroyed a third of Christchurch in 2011.
We were evacuated and let back in. All the planning in the world doesn't prepare you for the real thing, the first thing you're meant to do is keep calm, and I sure as hell didn't. I sprinted right the fuck out of my apartment building, I have 4 levels above me, hiding under a table wasn't going to do shit to save me.
The building has some cracks in the plaster and food has fallen off all the shelves, but nothing serious. The water seems to be running a bit brown though, so maybe some damage to the water pipes.
Props to the crew at Bizdojo (http://www.bizdojo.com/) for opening an invitation for us to come and chill there if we couldn't get back into our homes. Doing the right thing there!