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Martin Hunter / Getty Images
A man stands in remains of a building on February 22, 2011 in Christchurch, New Zealand. The 6.3 magnitude earthquake was an aftershock of the 7.1 magnitude quake on Sept. 4, 2010.
A 6.3 magnitude earthquake toppled buildings, buckled streets, and killed at least 100 people in the southern New Zealand city Christchurch Tuesday – a far worse toll of death and destruction than the 7.0 earthquake that hit the same region on Sept. 4, 2010, but resulted in no loss of life.
Why?
"The main reason is that this earthquake is basically under Christchurch whereas the one in September was approximately 30 miles away," Don Blakeman, a geophysicist with the U.S. Geological Survey's National Earthquake Information Center in Golden, Colo., told me.
Although 30 miles doesn’t seem all that far, he said the distance appears to have made all the difference. Another factor could be the shaking characteristics of the quake — this one may have had higher frequency waves, which cause more damage, but that's not known at this point.
Aftershocks
Tuesday's event was likely an aftershock from the September event and is consistent with a migration pattern of aftershocks away from the epicenter of a major quake, according to Thomas Jordan, director of the Southern California Earthquake Center at the University of Southern California.
"What we are seeing now is that the aftershock activity has moved to the eastern side of that fault zone and that's not untypical. Sequences of earthquakes will propagate along a fault structure," he told me.
Although it was an aftershock, it was a large aftershock, he noted.
"Most aftershocks are typically small and they themselves don't generate many aftershocks, but occasionally, and as far as we can tell randomly, one of those will turn out to be a big earthquake itself and then it will have an aftershock sequence," he said.
Tens of aftershocks have already been felt in Christchurch since the 6.3 earthquake on Tuesday, according to news accounts.
Reports indicating that a contributor to Tuesday's death toll was the timing of the earthquake (it happened in the middle of the day when people were out and about, whereas the September quake was in the middle of the night when people were at home in bed) are misguided, Blakeman said.
"This is a very general thing, but there tend to be more injuries when people are at home in the evenings, especially at night, just because they are all in buildings," he explained.
Earthquake infrastructure
As bad as the toll from this earthquake in New Zealand, it won't be as devastating as the shallow, 7.0 earthquake that struck essentially beneath Port au Prince, Haiti, in January last year. That's mainly because Christchurch is built to withstand temblors.
"In Haiti, a lot of the structures are very, very poor," Blakeman said. Poor construction with an earthquake centered on the city was a recipe for disaster. Of course, the Haiti earthquake was also much larger — 7.0 versus 6.3.
One of the reasons Christchurch's infrastructure is built to withstand earthquakes is because New Zealand, like Southern California, is bracing for even bigger earthquakes in the future.
One of New Zealand's major fault systems, the Alpine Fault system, is analogous to the San Andreas Fault in California, noted Jordan, in that it has primarily strike-slip motion on it and is expected to rupture sometime in the future with a large earthquake.
"New Zealand has another aspect to it: it is also being squeezed, especially to the north but even in this region one can see the effects of that kind of compression from the plate tectonic motions that are occurring in the area," Jordan added. "That gives rise to subsidiary faulting such as you are seeing here."
John Roach is a contributing writer for msnbc.com. Connect with the Cosmic Log community by hitting the "like" button on the Cosmic Log Facebook page or following msnbc.com's science editor, Alan Boyle, on Twitter (@b0yle).
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When are seismologists going to stop using the inane term "aftershock". Its pretty much meaningless.
Aftershocks have been studied and tend to follow certain patterns, depending upon the type of quake, conditions and magnitude. While no one is able to predict their occurrence, the likelihood of them occurring does seem to follow several models. Inane as it may sound to us laypersons, the fact is related smaller quakes DO happen following a larger one, and in many instances, related smaller quakes occur BEFORE the major event as well.
The latest information from the G.N.S service is that this is a new fault here and not part of the Darfeild fault. The aftershock banter is regarding the stress put on this new fault in lyttleton from the previous 7.1, however it is earthquake.
This one did feel worse as I was at work and we had to finish surgery in torchlight while we kept getting hit by shocks, staff screamed and cried. I had to drive home avoideing the road opening up and liquifaction to find my daughter at school, herself standing in liquifaction and avoiding cracks. However the 7.1 was in the dark navigating your home in pitch darkness being thrown around is also terrifying.
I beleive there are faults all under us, my home has had some decent shakes yet they havent shown up on geonet etc, i dont believe they are monitoring enough of ChCh.
Inane term? Meaningless? I think not, S the man. Research the term then comment.
When does an "aftershock" become just another earthquake?
When it is unrelated. Either a different fault of a different plane.
Chris is quite right. Here in Chile where we suffered a quake of 8.3 on 27 February 2010, we have several tremors a week and all hours of the day. I have learned to sleep through them, though my wife hasn't. They consist of a noticeable shaking for 5-10 seconds, sometimes longer. Seismologists here say that these tremors relieve stresses building up as the Pacific Plate sinks under the Continental Plate, thus preventingf another Big One. It is noteworthy that Chile suffered only about 385 deaths in the 2010 quake, compared to more than 200,000 in Haiti, six weeks earlier. Azad Kashmir (Pakistan) suffered 34,000 deaths in a quake of some 6.9 in 2005. A lot depends on construction methods and on the time of day the quake hits.
When it happens to someone else.
"This is a very general thing, but there tend to be more injuries when people are at home in the evenings, especially at night, just because they are all in buildings," he explained.
In this particular case, this is not true. It happened during the middle of a business day, so there were a lot of people in the central part of town, probably the most devastated area. In the September quake, again the central area was heavily affected, but as it happened in the middle of the night, on a weekend, everyone one was in the relative safety of their homes.
QUICK---get major entertainers to have a benefit for these people---they lost homes, businesses and family members. What??? No one is coming forward ?? WHY???
Millions were raised for Haiti--a third world dicitatorship. Now it's time to step forward and quit funding corrupt governments and aid a country that is democract and an ally.
Each and every celeb/rock star and rich people who donated time and money to help Haiti need to do it again for the Kiwi's. Why are you waiting???
you're an idiot
Completely agree with teach. I lived in CHCH for 3 yrs. The Kiwi's are wonderful people and yes allies. We should be giving them our full support!
joe mota - You broke the Code of Honor.
You can disagree. You can prove them wrong with evidence. You can't be calling another member of Newsvine an idiot or any other derogatory word. Please be respectful.
Is there any warnings, such as animal's behavior from the ground to the sky, before the quake?
Can the quake expert have data to predict and to warn the quake is coming?
The quake experts have been giving warning to the government of Haiti about the big quake but no one listened and took them seriously.
The N.Z. quake in last September has moved/shifted the ground upward about 1.5 feet in the quake area.
The Christchurch may be no longer safe for human habitats.
May quake experts continue to extend their studies, such as warnings from animals and from the ground or the neighbor areas.
Hope the N.Z. people are in safe shelters.
It is my hope that someday very soon we will be able to forcast earth quakes just like a weather storm. How ever sill, this one though may be, I believe it to be possibile. My condolences and best wishes to all of those who find themselves strugling in this so dire time.
The problem comes with the in-exact nature of them. Where do you set the threshold for likelihood of a major quake before sounding the sirens? 60% chance? 80%? How precise is that estimation? As a geoscientist I can tell you that no such precise forecasting exists that works with any certainty.
Think about it - you're talking about shutting down a megacity like Los Angeles, causing what could likely be a panic as people try to flee the area..... and then it doesn't happen. If you're a political figure who made the call, "you got some 'splainin' to do, Lucy". Not to mention that if you sound the alarm enough without something happening - people will start ignoring it, and then when the big one DOES hit - people are likely no better off than if you did nothng.
I dont see quake prediction as possible thing. for sure. aftershocks are just the area resettling to a non-slip motion, like gravel on a river bed setling after a larger stone is removed.
My family lives in Tauranga on the North Island, and I feel for the South Islanders in Christchurch. A benefit by the world's celebrities is a good idea, but would they ever see the money? Haiti is still waiting for the bulk of the promised aid. People living in quake-prone countries should follow the Japanese lead, don't they have quake-proof buildings in Japan?
The amount of earthquakes each day is almost unbelievable. Their is a web page to show all quakes each day. I researched as far back as 150 years and the quakes are getting alot larger and with many many more per day than ever in history. I could probably tell you why, but I am sure most people can read between the lines. The day is coming for many big quakes, then the final one is very large. The volcano's are probably or should be more frightening. The Yellowstone magnum that is ready to explode is not even talked about. It will wipe out the North American Continent. We will be in darkness for years, just think nothing live in the dark, we all need light to survive. Very interresting though. I pray every minute of the day lately. You never know, but it is going to happen. Just don't know when. Look Up
Cheryl - I have good news from the U.S. Geological Survey:
Earthquakes are not on the rise. We are better at reporting and tracking them, and the media is doing a better job of reporting on them.
Cheers! ~Michael (AFM*Radio / Astronomy.FM)
With the increasing use of large-scale internal stress modelling of rocks along faults, earthquake prediction will begin to resemble weather prediction, but the scale will be way different, I imagine something along the lines of, i.e. 30% chance of 6.5 quake centered approximately Somewhere during the next 18 months. Unless and until we can get a ridiculously overwhelming number of sensors on and in the ground, it is not likely to get better than this because of the granularity of the data. Think of a talus slope, it is easy enough to guess approximately when a slide will happen, but we can't say for certain that a specific pebble is going to start a slide unless we know the pretty much the entire stress state of the surface of the slope.
Maybe its becoming time for the earth's poles to shift? Imagine the day it happens. Yikes!
A very mysterious and wild planet we live upon. There's no telling what will happen next.
Our son lives in Christchurch and was in his office, on the 10th floor, downtown, when the quake struck. He made it down the stairs, thinking, Is this it, will it be painful, will it be quick?" Thankfully, he never found out. The building behind his was completely collapsed. His 9 yr old daughter and 6 yr old son were in the playground at school when it struck. She told her Daddy that the ground opened just a few feet from them. My point, we can all reflect on the realities, causes, warnings, and there is really nothing we can do to prevent them. Our families, our children, our friends and neighbors, even strangers, are of great value and we all need to prepare for the worst and hope for the best. Our son and his wife put a plan of action into play which was very valueable during both quakes in NZ. They made an action plan, what to do, where to meet, etc. They also have an emergency pack made up with water, food, non-perishable items, first aid kits, batteries, radios, clothes, and they are good to go for a week, at least. We worry and pray for not only their safety, but for the safety of all peoples of New Zealand and the world. Remember the school drills, where we were told to hide under our desks? Or, we were told to meet in the hallways, with our backs to the walls? It is my belief that if more people were educated as to what to do to prepare for these types of disasters, made more aware, and given help to prepare, maybe, just maybe more lives would be saved.
Man has for a long time been sucking oil out of the bowels of the earth so repercussions should be expected. Millions of barrels per day taken out of the earth's structure surely should be considered risky. It is most certainly there for a reason and I'm not talking about to provide engine oil for automobiles, etc. Greed is the logical culprit and there is no end in sight. So, isn't there a likelihood that the oil removal from the earth could be cause for earthquakes?
The short answer is no. Extracting oil has nothing to do with tectonic plates and fault zones. Earthquakes have everything to do with movements of the *entire* surface of the earth. Contemplate that for a moment. The energy released in a quake doesn't come from activity at a fault zone. The fault just serves as place where some of the energy present in the movement of trillions (quadrillions?) of tons in the different plates gets stored and concentrated and then released very quickly. It might be a surprise to you, but people and their activities really aren't responsible for every thing "bad" that happens on and in the earth.
That is what I always thought Jake. And greed will be our undoing.... So sad most of us have no say about what they do to our planet.
Jake...Are you also blaming the oil companies for all the major earthquakes that occured before the 1800s all over the world? I didn't realize that Ancient Greece was drilling for oil when the earthquake toppled their buildings.
I also wonder if the earlier quake weakened some of the buildings. Perhaps not enough to be structurally unsound when the ground was holding still, but enough so they weren't able to take another quake. It would be good to know if this was the case and if the damage was known, but people were allowed to use the buildings again pending repair. It might be an object lesson to other quake prone areas to keep people out of damaged building until they can be brought back up to full structural integrity.
Earthquake.
Reinforce your chosen survival area. A nail, a screw, a bolt. Add diagonal bracing, sheet of ¾ plywood over bathtub (get in tub). Make a survival kit. Improve your likely post-earthquake environment: Water, food, tools for extraction, crash-helmet, fire extinguisher, dust mask. Anchor t.v, water-heater, etc. Tie a fixed rope that reaches the ground, and leave it coiled on the wall next to an upstairs window. Tsunami: leave a rope tied halfway up a tree attached to your life-preserver (Clorox-bottle?) Brick masonry house: Move out.
Anyway I don't see how they can call this 'their 9/11', this has nothing to do with terrorism. Unless, that is, they believe earth is terrorist :P
Maybe it would have been better to call it their Great Quake, as in San Francisco's Great Quake of 1908.
TruthSeeker
Your a dick! How old as you ,15?
I'm in Christchurch and apart from everything I have witnessed personally I have also seen just about everything broadcasted as well.Nobody here calls this our 9/11, what a stupid comment.The only references at all to 9/11 was actually from some Americans who commented that the dust thrown up from the falling brick and concrete buildings was like 9/11 all over again.
No it was not like 9/11 moron. You have no clue what 9/11 did to our country. And for you to think your earthquake is like 9/11 goes to show how ridiculously under-educated you are.
Terrorism is terrorism. Mother nature is not a terrorist. She might bring terror into our lives but she by no means is a terrorist. And yes, it was someone in your city calling it 'Your 9/11'. Get your facts straight.
Call me a child all you want, you have no clue what you are talking about. Comparing your meager earthquake to 9/11 is simply idiotic, to say the least.
Have some respect for my country by not comparing your natural disaster to the mad made catastrophe that hit us on 9/11!!!
Truthseeker
Post the quote then to back your comments.Who actually made these comments you keep going on about?
I have my facts straight and NZer's do have a lot of respect for America and are grateful for the help from your disaster response teams sent over.
Show everyone reading this the proof us dumb uneducated kiwis go around making these comparisons.
Again it was an American who must have witnessed 9/11 stating in an interview the dust thrown up by the falling bricks brought back memories to them of that event.
There is pics taken from a hill above town showing just before the earthquake and immediately after with a huge dust cloud over the CBD
Based on your posts above you must either be a child or a sick individual calling an earthquake that kills hundreds of people meager.How about you showing some respect for the families of over 20 different nationalities who lost their loved ones.
I think any Americans who have lived on your West Coast along your own fault lines and experienced their own terrible quakes would not think a 6.3 directly under their feet was meager.nor the fact it was months after a 7.1, nor that reports are stating this "Aftershock" released over 2G of force and was one of the highest ever recorded in the world thus causing our "meager" quake to be so destructive.
Nor would anybody call a quake causing 1/3 to 1/2 of their citie's CBD to have to be torn down (if not already down) "meager"
Nor would anybody who has to find $10 billion plus to fund the rebuild.
Go get some help Truthseeker.
TruthSeeker & Kyle;
It's taken five days, but I now know that everyone I know in Christchurch - aunts, uncles, cousins & their kids, friends, and colleagues - are all alive. Several were airlifted to other cities to be hospitalized, but are expected to recover.
Half of their homes are heavily damaged, but may possibly be repaired. Two homes were destroyed; one was torn down while my cousin Craig and his kids sat on the curb and watched it be demolished; his wife is in the hospital 150 miles away, and did not see the home that they had built together bulldozed flat.
My mother is from Christchurch. I was born in Detroit, but I spent a lot of my youth in Christchurch. I went to school there, and even climbed the cathedral spire that is now lying in a heap, with the possibility of 22 bodies buried under it (a missing tour group).
You don't know me from Adam, but I'd consider it a personal favor if you two would please cut the crap until we have at least buried our dead. After that you are free to beat up on each other to your heart's desire.
Thank You. ~Michael
Hi Michael
I hear you and I'm glad your relatives are all ok.
I'm here in Christchurch sitting in my house ruined and marked to be torn down from the Sept Quake.Luckily the west side of town didn't feel the full force this time but we still had a mess inside and I had doors jambed shut as the house is further off it's piles.
Shame My family and I wasn't at home when it happened.I had just left the Cashmere Hills area (which was hit pretty hard) and had stopped at Macca's in Riccarton for lunch when it hit.
It was short (compared to Sept and a R7 Ihad been in in Queenstown years earlier) but incredibally strong, knocking me off my feet and everybody was screaming.Next thing it's over and lucky for all us we were in a brand new building so I think no one was badly hurt.
Next thing everybody is on their cell phones trying to check on family but nothing works.I'm worried as hell as my wife and my two young kids went shopping in town.I jump in my truck and make my way out onto Riccarton Road to head into town.Close to town you start to see buildings down and lots of liquidfaction.I get a text from my wife asking for help and they can't get to the car so i'm getting scared @!$%#less now.bealy Av up near the CBD is a mess with many buildings down and people running, driving everywhere.I get another text from my wife saying they got out and are heading home so i turn for home to meet them.Papanui rd is blocked by a building down on the corner so i take to the back streets,Everywhere you go there's house split in two or holes in roofs or gapping cracks in the road.Took over an hr to go what usually would take 15mins.My wife arrived home 20 long minutes after me, crying hysterically.She had fortunately decided to go to a shopping centre in Shirley instead of the CBD but was in a shop when the quake hit with a dryboard ceiling completely collapsing on them.My wife luckily was able to put herself over the kids and take the force of the boards across her. Even so my nearly 4 yr old daugther got hit by some and a full sheet narrowly missed my son.The shop front windows exploded showering small bits of glass everywhere (lucky for safety glass) and water pipes above burst.My wife and kids got helped out of the distoryed shop by the assistants and as she was just breaking down into an emotional mess was helped by a lovely elderly couple who got them through the dark centre and out into the carkparks.A nice security guard then waded through knee high water and sewage to get our car under a dodgy looking roof.
Lucky for us a few bruises are extent of it and I'm thankful it was not bricks that hit my family. With our relatives and friends safe we have personally not lost anyone ,thank god and buildings can be rebuilt but my kids are traumatised and scream with every aftershock (luckily the shocks are deminishing a bit).
We all have heaps of stories like my wifes friend who works in A and E at ChCh hospital and she is haunted by all the dead and dying children she saw.The unbelievable injuries sustained from falling bricks and concrete on so many people.
The scariest thing about an Earthquake is that there is no warning and many of the places destroyed are places we go to or walk past like winnie bagoes restaurant and so many others.
Anyway you might understand why I think that guys a twit.
Yes, he is (a bit). And I'm glad that you and yours are together and pretty much OK.
So many that post here on Newsvine are thinking in the abstract. It doesn't even occur to those folks that all too often there is real disaster, and real people who are hurting.
I've heard that the University of Canterbury has gotten through the quake fairly well (considering), but I've not been able to get a hold of a couple of members of the faculty that I work with (I'm sure that they're likely OK, just very busy getting lives back in some order). Do you have any idea how the University rode out the quake?
Take care, mate. The next time I'm in ChCh the first round is on me.
Cheers! ~Michael (AFM*Radio / Astronomy.FM)
Hi Michael
I think as far as students and lecturers go, they are all ok but I don't know about the buildings.They were playing an audio recording of a leature when the quake hit with lots of screaming and loud shaking from the building and furnishings.In tipical kiwi fashion the leaturer can be heard at the end "Ah, and that concludes this leature".
Go to www.canterbury.ac.nz/ as it has links and pics that might help you track down who your looking for.Hope you find them all well.
The students have been great, they have formed an 18000 strong student army going into the suburbs and cleaning up the mud from the liquidfaction which is over a foot deep in places and in some spots there are huge holes filled with mud.
Those old uni buildings are a worry, I have two cousins that work at Lincoln, I got a text saying they were ok but i haven't heard about the buildings.
regards Kyle
Don't get me wrong, I totally feel for those who have lost their homes and even worse, those who have lost their lives or the lives of loved ones. But to compare this to 9/11 is going a bit too far. And no it wasn't an American who muttered those words. Just a little respect for the THOUSANDS of people who died on 9/11 and the thousands more who have died from the war on terror is in order.
My apologies if I sounded like a jerk, but come on, have a little respect for our fallen citizens. That's all.
mate, you do sound like a jerk, you can't seem get it in your head that some people have had the misfortune to experience both and have just expressed their view about horrible memories of dust clouds clogging their vision and breathing not to mention the noise.
You are obviously a bit unstable or lack comprehension of the English language so i'm wasting my time here no more.
Have a good life and may our paths never cross.
First off, I'm not your mate, son. Second of all, for anyone to use a cloud of smoke as a reason to say they're scenario was like America's 9/11 is beyond distasteful, it's utterly moronic. That's my opinion, you may have your own but that's only because you are not American. So if I need to be a jerk to make my point, so be it, I'm proud to stand up for what's right.
Yes, being a jerk about a minor point, over and over again, with someone who is in a disaster zone, is something to be really proud of.
That's my opinion, and I'm an American. Further, I'm a retired Marine.
Truth, you are making us look bad. Let it go.