Quake Shook Earth To Core

[JackiePenn]

http://news.independent.co.uk/world/scienc...sp?story=596798

shook the Earth to its core, scientists believe, accelerating its rotation and shortening days by a fraction of a second

may have shifted some small islands in the region by more than 30 metres.

believed a shift of mass towards the Earth's centre caused the planet to spin three microseconds - one millionth of a second - faster. It also caused the planet to tilt around 2.5cm on its axis.

Earth more compact and spinning faster

changes were too slight to be detected by global positioning satellite networks.

 

Full Story

[+Birders]

<<changes were too slight to be detected by global positioning satellite networks.>>

 

Pheww - thought we were going to have to go and move all ours 30 feet to the right.

[+MarcB]

Wow, that was one hell of a quake

MarcB

[+sTeamTraen]

may have shifted some small islands in the region by more than 30 metres.

 

changes were too slight to be detected by global positioning satellite networks.

Conclusion: "may have shifted... by more than 30 metres" in fact means "in fact it didn't, otherwise the satellites would have been able to display the difference, but it sounds more dramatic this way".

[JackiePenn]

Conclusion: "may have shifted... by more than 30 metres" in fact means "in fact it didn't, otherwise the satellites would have been able to display the difference, but it sounds more dramatic this way".

Ah, well I can't make such "conclusion" on just one news outlets report of the story. Got to research backward to find the source of the 30 metres...

 

Here we have a CNN Story" saying things like...

 

moved the tectonic plates beneath the Indian Ocean as much as 98 feet (30 meters), slightly shifting islands near Sumatra an unknown distance, U.S. scientists said on Tuesday.

 

Satellite images showed that the movement of undersea plates off the northern tip of Sumatra moved the Nicobar Islands and Simeulue Island out to sea by an unknown distance, U.S. Geological Survey geophysicist Ken Hudnut said.

 

Although the data showed that plates more than 12 miles (20 km) beneath the ocean's surface moved dramatically, scientists will have to use handheld satellite positioning systems at the sites to learn precisely how much the land masses on the surface shifted, Hudnut said.

 

So... there we go, Ken Hudnut is the voice... lets look him up and his recent doings...

 

Here are his homepages at USGS http://pasadena.wr.usgs.gov/office/hudnut/. Kinda looks like he might be qualified to theorise and speculate based on his CV.

He is the scientific authority that gets dragged out on such occasions for the science viewpoint, and it looks like the official news source for all these stories.

 

I guess only time will tell if this guy has said these things for, like you say, dramatic effect. But he made these statements based on seismic modeling so he can always blame that either way.

Edited January 2, 2005 by stonefisk

[+The Forester]

If anyone thinks that tsunamis only happen in exotic tropical locations, they're wrong.

 

The Storegga Slide, an underwater landslip, generated a huge tsunami which travelled many hundreds of miles.

 

Synopsis

 

One of the world's largest submarine slides with a total volume of ca. 5,600 km3 occurs on the continental slope west of Norway. Part of the sediment complex, with a volume of ca. 1700 km3 is generally believed to have moved as an underwater slide approximately 7200-7300 radiocarbon years ago. The scale of the slide deposit is demonstrated, for example, by a scarp slope 150km in width that defines the head of the slide and by individual blocks of Quaternary sediment up to 200m in length that are incorporated within the slide complex. The sudden movement of sediment across the Norwegian continental slope and onto the abyssal plain of the Norwegian Sea is believed to have generated a large tsunami that was propagated across the North Atlantic and Norwegian Sea regions. Deposits attributable to this tsunami have been discovered at numerous coastal locations in western Norway, Scotland, Faeroe Isles and as far south as eastern England. Modelling of the slide and tsunami appear to indicate that it had an average velocity of ca. 35m/s and it is estimated that the majority of the sediment mass was moved during approximately 2 days. Modelling of the tsunami runup at the coast would appear to suggest that at certain locations in western Norway, the generation of the tsunami was associated with an initial drawdown (lowering) of sea level at the coast in the order of -8m and that this was quickly followed by a sea surface rise in the order of +16m. Geological studies of coastal deposits in Scotland and Norway attributable to the tsunami indicate that the tsunami runup exhibits strong local and regional variability that was strongly influenced by coastal configuration and the effects of wave resonance within individual bays and estuaries. In parts of the Shetland Isles, the runup at the coast may have been as much as between +25/+30m above sea level. It is not known if the slide was generated by a large offshore earthquake or by gas release from within the slide sediments.

 

A 25m to 30m tsunami strike makes the recent monster in the Indian Ocean, which was about 10 metres tall, look like a tiddler in comparison.

 

If there were ever to be a repeat of the Storegga slide, perhaps caused by global warming triggering a massive release of gas hydrates which in turn destabilise the slope, you can kiss goodby to much of Lincolnshire, Norfolk, Suffolk, Essex and at least two-thirds of Holland. --- as well as doing horrible things to our DnF totals!

 

Cheers, The Forester

[JackiePenn]

If anyone thinks that tsunamis only happen in exotic tropical locations, they're wrong.

mmmmmmmega-tsunami

 

There is also a predicted landslide in on La Palmam in Canary Islands. Said that if it does splash down in one peice the result would be a 50m high mega-tsunami hitting the USA Eastern sea broad. The research is disputed but the original Press Release is here.

 

Latest news from the Canary Islands are mass sightings of hammer and chisel wielding Islamic terrorists..

 

Similar big wave events can happen with landslides into canyon-ed lakes where the wave travels down river with tremendous destructive force.

[+The Forester]

There is also a predicted landslide in on La Palma in Canary Islands. Said that if it does splash down in one peice the result would be a 50m high mega-tsunami hitting the USA Eastern sea board. The research is disputed but the original Press Release is here.

I saw a documentary about that thing. If it ever does let go, it will trash the entire Murricane coast from Florida all the way up to Canada's Maritimes.

 

Rather worrying for me personally because almost my entire family lives on Long Island NY, less than 20 metres above the high water mark and just a short walk from the Atlantic coast.

 

Evacuating everybody from the endangered area in the time it takes a tsunami to rip across the Atlantic at 500 knots just ain't going to happen. Shortly after Chernobyl, while a nuclear power station was being built by LiLCo on the North coast of the island in Suffolk County, a paper exercise was conducted to see how long it would take to evacuate the island in case of a whoopsie at the nuke plant. They reckoned three days! As a result, they have never actually switched that switched it on. It's just a multi-billion dollar white elephant.

 

I don't know how useful a tsunami warning system would be in the event of that rocky ridge on La Palma letting go. I guess it would give you just about enough time to put your head between your knees and kiss your bum goodbye! What it would do to the global insurance and reinsurance industry is anybody's guess.

 

Boxing Day's 10 metre tsunami has killed something like 150,000 people (perhaps many more), has rendered 1.8 million people totally devoid of water or food or shelter and has rendered 5,000,000 homeless and destitute. What would a 30 or 40 metre bruiser do?

 

Cheers, The Forester

[+Simply Paul]

Any meteorite strike in deep water, even a 'relatively' small 20m diameter rock, could cause serious wave damage to any nearby landmass and kill many more than a simple shockwave impact on land could. 200m could kill tens of millions by sending waves all around the world and something of 1km in diameter could kill us all. The surface of the earth is 70% water so it's likely any significant impact would be in the sea somewhere. It's one of those 'it's only a matter of time' things. However, unlike earthquakes, it is something we could perhaps stop happening given investment in suitable current technology. Although some asteroids are big enough to have their own little moons, it is possible to track them and predict their orbits. When ones which astronomers call a PHA (Potentially Hazardous Asteroid) are discovered at least we have some warning of a possible (then perhaps likely, and with more readings taken of mass and motion, inevitable) impact, and can/could act to change its orbit.

 

Does anyone else remember what fragments of the Shoemaker-Levy 9 comet did to Jupiter in 1993, or what probably exploded over Tunguska in 1908? I'm not making light of recent events. I just think it's worth knowing that we can count ourselves very lucky. A ten thousand tonne fist of ferrite rock hitting the North Atlantic at ten thousand miles per hour could see the British Isles, lots of western Europe, north Africa and the eastern seaboard of the USA and Newfoundland in a very similar state of destruction.

 

SP

Edited January 2, 2005 by Simply Paul

[+The Forester]

A ten thousand tonne fist of ferrite rock hitting the North Atlantic at ten thousand miles per hour could see the British Isles, lots of western Europe, north Africa and the eastern seaboard of the USA and Newfoundland in a very similar state of destruction.

Wouldn't there be ample notice of such an asteroid coming our way?

 

Most of the near Earth asteroids are quite well mapped in their orbits and if a real biggie were to appear to threaten to bump into us then surely there would be the mother and father of all international co-operative efforts to do something to divert it?

 

One of the many horrors of this recent catastrophe was that there was no way of predicting that the Mag 9.0 quake was going to happen and there was no tsunami monitoring network to trigger a widespread alrm to get people away from the waterline. They have such a network in the Pacific and the North Sea storm surge network could easily be adapted to detect tsunamis with a bit of augmentation by installing appropriate kit on some of the offshore production platforms and weather buoys.

 

Still, I take your point that a big enough meteorite smacking into an ocean or sea could be at least as devastating as last week's monstrous tragedy. Even a bolide such as the Tunguska event, which completely disintegrated long before it could get to ground level, would seriously mess up a major conurbation.

 

As for the current event, there is a major geophysical and hydrographic effort being planned right now as I type this post which is being mobilised to quantify just what this event did to the seabed. None of the three geophysicists I've talked to this evening/morning knows of such a massive subduction event within living memory.

 

Cheers, The Forester

Just when mankind thinks he can tame Mother Nature, she bites him in the bum.

[+Simply Paul]

Wouldn't there be ample notice of such an asteroid coming our way?

 

Most of the near Earth asteroids are quite well mapped in their orbits and if a real biggie were to appear to threaten to bump into us then surely there would be the mother and father of all international co-operative efforts to do something to divert it?

Define ample. A recent near-miss (inside our moons orbit) was only spotted four DAYS before the asteroid passed us. In living memory several long-lived fireballs have been seen in the sky, the evidence of something weighing several tonnes at least passing through the Earth's upper atmosphere before 'bouncing off' and heading back into space - a very near miss indeed. Ample would also depend on the size of the rock. Perhaps five years would be long enough to intercept and divert something of a few hundred tonnes but as the rock gets bigger, the more time would be needed to deal with it.

 

The problem with near-Earth objects are 1) we keep finding new 'local' asteroids, suggesting they're not all that easy to spot 2) The route of any body with a highly elliptical orbit will bring it close to Jupiter (or Saturn, to a lesser extent) eventually which can wildly change its orbit in fairly unpredictable ways. 3) Comets can have such long periods that they tend to appear irregularly (at lest in terms of recorded history) and can be moving very quickly as they fall back towards the sun. Also, a comet's nucleus can be so dark before it begins outgassing and forming a coma and then a tail or tails that you could look straight at it with Hubbell and not see it before it's only months away as it passes the orbit of Mars and warms up.

 

I'd like to believe mankind could do something to stop an impact, but I suspect given anything less than a couple of years warning, there really wouldn't be anything we could do except build rough shelters and hope for the best.

 

How off topic is this? lol! I have to admit, faced with the extinction of the Human race, I wouldn't bother to archive and collect my caches first...

 

SP

 

P.S.

The violent explosion of the volcanic island of Krakatoa in August 1883, generated a thirty meter high tsunami wave that killed 36,500 people in Java and Sumatra. On 19 August 1977 a large earthquake in the Lesser Sunda Islands in Indonesia generated a destructive tsunami which killed hundreds of people on Lombok and Sumbawa islands along the eastern side of the Indian Ocean. Its effects and damage extended to Australia.

I think it's safe to say this area has always had this problem and last week's horrific tragedy was predictable - but sadly not for its timing or its unprecedented scale.

[JackiePenn]

Wouldn't there be ample notice of such an asteroid coming our way?

Talking of asteroids heading our way, I take it you guys seen this recent story.

[nobby.nobbs]

the sky's falling, the sky's falling!

 

i don't think about things with odds that long. i'm usually too busy filling in my lottery tickets.

 

as regards doing anything about them. small rock heading towards earth at several thousand miles an hour. we have trouble designing a rocket system that will take out incoming planes. what chance against the meteor?

 

it's ok the aliens will save us. or atleast those of us who believe in them!

[+The Forester]

we have trouble designing a rocket system that will take out incoming planes.

You're kidding, right? Ever heard of Gary Powers? That was in the early 1960s, using 1950s technology.

 

Are you aware that last year a spacecraft was successfully guided to a gentle landing on an asteroid called Eros. That craft wasn't even designed to land, only to survey the rock, but when they'd finished the original mission they steered it onto the surface in a gentle and survivable touchdown despite not having any landing gear.

 

 

what chance against the meteor?

We're not talking about intercepting a meteor. An asteroid or a comet only becomes a meteor when it enters the Earth's atmosphere. By then it's obviously far too late to do anything about it.

[+sTeamTraen]

That article suggests that the asteroid has a 1-in-60 chance of hitting the earth, but as far as I can see it means that the observers are only 98.4% certain that it will miss us - not the same thing at all. Still, it fills newspapers, I suppose.

 

By the way, has anyone else noticed that we are only hearing about the menace if asteroids since the people who build ICBMs have been made redundant by the end of the Cold War ?

[+The Forester]

The violent explosion of the volcanic island of Krakatoa in August 1883, generated a thirty meter high tsunami wave that killed 36,500 people in Java and Sumatra. On 19 August 1977 a large earthquake in the Lesser Sunda Islands in Indonesia generated a destructive tsunami which killed hundreds of people on Lombok and Sumbawa islands along the eastern side of the Indian Ocean. Its effects and damage extended to Australia.

I think it's safe to say this area has always had this problem and last week's horrific tragedy was predictable - but sadly not for its timing or its unprecedented scale.

Castastrophic tsunamis are several orders of magnitude more common events than catastrophic encounters with meteorites or bolides. As you yourself have pointed out, there have been several in the last couple of hundred years, but tens of millions of years have elapsed since the last really major asteroidal impact (end of the Cretacious?)

 

A lesson from this recent tsunami is that we need to spend a bit more time and effort and a wee bit of money on installing a detection and warning system in risk areas such as the Indian Ocean, the North Sea and the Atlantic.

 

In this recent case, I don't suppose such a warning system would have done Aceh any good as it's so close to the epicentre of the quake and the lead time from detection to impact would have been much too brief to implement any evacuation plan, but over longer distances a warning system could save a significant proportion of the potential victims. Even if only 10% of the lost lives in Thailand, India and Sri Lanka could have been saved, it would have been money well spent.

 

Cheers, The Forester

[+kbootb]

 

There is also a predicted landslide in on La Palmam in Canary Islands. Said that if it does splash down in one peice the result would be a 50m high mega-tsunami hitting the USA Eastern sea broad. Similar big wave events can happen with landslides into canyon-ed lakes where the wave travels down river with tremendous destructive force.

Radio 5 (live) picked up on that and ran an article on that at about 7.30 this morning. No new info as far as readers of this thread are concerned, but intersting to note that they considered this one to be the major predictable event of this nature.

 

BTW who is the Eastern Sea Broad?

[+kbootb]

Wouldn't there be ample notice of such an asteroid coming our way?

Talking of asteroids heading our way, I take it you guys seen this recent story.

To keep up with latest predictions look at the NEAR web page.

 

Looks like the risk is lowering again.

[+The Forester]

To keep up with latest predictions look at the NEAR web page.

 

Looks like the risk is lowering again.

The risk is now down to a probability of 1:27,027 against this thing hitting Earth at 12:14:24 on Sunday the 13th of March 2053.

 

That's 517.4 times more likely to happen than a £1 ticket winning the jackpot on the British National Lottery.

 

The downside is that such an impact will release the equivalent energy of 2,040 MegaTons of TNT, which is approximately 4.3 times as much energy as was released by the recent Andaman/Sumatra quake which triggered this tsunami.

 

We're all going to have to make doubly sure that the tupperware lid is on good and tight that day!

 

Cheers, The Forester

[+sTeamTraen]

Even if only 10% of the lost lives in Thailand, India and Sri Lanka could have been saved, it would have been money well spent.

Without wishing to get too cynical/mechanical etc: such a system would probably cost a fortune, and might not be "needed" (as in, detect an event in such a way that it could evacuate people) for another 40 or 50 years. It would require substantial maintenance, an army of civil servants to run it, put lots of money in the pockets of the usual suspects (defence contractors, computer firms, civil engineering multinationals, 20% off the top for the government officials in at least half the countries concerned, etc). And if it didn't work anyway when push came to shove...

 

For a fraction of the cost we could provide clean drinking water for some of the 100,000 people who will die worldwide this week from water-borne diseases *outside* the tsunami area. But the local companies who would do the work don't have the lobbying power of the big firms who claim that they can build a system that would prevent the "exact same" disaster happening again.

[+Brenin Tegeingl]

A detection system is not needed, if you look into some of the news items about the tragedy, there was enough time after the quake took place to give an hours warning. What was not able to happen, was the warning being able to be passed on in such a way as to have a effect, both the UK and US embassies in the area received advanced warning, but were not able to get the info to the "right people" in time. This is now being looked into, how to best put in place a warning system, to receive the "Alerts" in time. As was stated at the time all it would have taken was a 15 minute walk in-land, and thousands would have been saved. Unfortunately a lesson has been learned too late once again!

 

Dave

[+The Forester]

might not be "needed" (as in, detect an event in such a way that it could evacuate people) for another 40 or 50 years. It would require substantial maintenance, an army of civil servants to run it, put lots of money in the pockets of the usual suspects (defence contractors, computer firms, civil engineering multinationals, 20% off the top for the government officials in at least half the countries concerned, etc). And if it didn't work anyway when push came to shove...

All true, but the fact that this event has happened changes everything.

 

It's a bit like airlines prior to September 11 2001 allowing passengers to carry small knives such as box-cutters aboard civil airliners. It only takes the benefit of hindsight after a ghastly event to completely transform people's perceptions about what precautions are wise and what are spurious.

 

I don't think you'll find many governments willing to oppose a tsunami warning system after 26/12/04.

 

Of course such a huge tsunami (or bigger) is unlikely to happen again in the next few decades, but given the consequences of this one for millions of victims, you'll find it difficult to persuade people to ignore the potential hazard.

 

Anyway, such a system is not vastly expensive. A network of a few dozen DigiQuartz sensors on the seabed with acoustic modems transmitting to SatCom-linked buoys doesn't cost much more than a million or so dollars, including installation and operating costs. That's chicken feed when compared with the financial costs of this disaster and the costs of the international aid effort which will be needed for the next couple of years - quite apart from the humanitarian aspects which are difficult to quantify in financial terms (unless you're the FAA!).

[Hello, I'm Johnny Cache]

But was it not known by monitoring stations that the earthquake/tsunami was imminent but the communication channels in the countries affected were either not in place or not good enough?

 

Here's the first news story I found in Google on this.

[+The Forester]

But was it not known by monitoring stations that the earthquake/tsunami was imminent but the communication channels in the countries affected were either not in place or not good enough?

I think you've put your finger on the nub of it, Rookie.

 

Devising a coherent network to assemble the information which forms the basis of a warning is doable, but the really tricky bit is disseminating the warning to remote villages.

 

Easy enough to do in the hi-tech societies of California, Hawaii and Japan, but a pig of a job in remote areas of places such as Kerala, Somalia and Aceh. It could be done, but there will be a risk of false alarms leading to panic and then complacency.

 

Slightly different subject: I hear this evening that GPS surveys on each side of the tectonic boundary which slipped are showing that there was a 20 metre oblique movement and about 10 metres of plate to plate movement. I'll be interested to see the bathymetric changes which this thing has wrought.

 

Those are the kind of horizontal distances which we can easily measure with our little hand-held GPSrs!

 

Cheers, The Forester