Sunday, 20 May 2007

Moving plates bending, stretching NZ

is in warp time – and it’s shaking us up.
No, we haven’t stopped the clock or begun scorching through worm holes in space. Instead, our landmass is slowly distorting.
It’s because we living on the edge, says GeoNet project director Ken Gledhill.
“We live on the boundary between the Pacific and Australian (tectonic) plates,” he says.
Global Positioning Systems show how our island nation is being pushed and pulled by these underground forces (pictured).
“It’s like a scissor action,” he says. “Us in Wellington are getting crushed and the people in the Bay of Plenty are being pulled apart.”
He is of course talking of our body of land, not our human frames.
“Where I’m sitting the plates are pushing together 5cm a year,” he says.
“The main effects on the upper surface are earthquakes.”
The GeoNet website explains. “The Earth’s entire outer surface is like a hard shell, which is made up of smaller pieces called ‘plates’. Under New Zealand, two of these plates are colliding with huge force causing one to slowly grind under the other; this ongoing process causes our earthquakes.”
Since May 1, there have been more than 30 decent shakes in New Zealand – four of which have been in Taranaki.
The strongest local shudder was 4.2 on the Richter Scale, recorded at 6.43pm on May 13. It was a short, sharp shock centred 10km south-west of New Plymouth, was 10km deep and felt like a truck passing by.
Nationwide, the biggest tremor was more than 10 times stronger than the New Plymouth jolt. It hit Nelson in small hours of May 14, measuring 5.4 on the scale and was 90km deep.

FREAKY get you quaking

THE formiddable power of our Earth is seen in the wake of big shakes. Here are Five Freaky Facts to consider.
1) The largest earthquake recorded in the world in the last 200 years was the 1960 magnitude 9.5 earthquake in Chile. It caused 5700 deaths and produced a large tsunami that made it to New Zealand, flooding the Gisborne Harbour (pictured).
2) The only earthquake ever predicted was in Haicheng, China, on February 4, 1975. Few lives were lost in the 7.3-magnitude quake because 900,000 people had been evacuated.
3) The highest tsunami ever recorded hit Lituya Bay, Alaska, on July 9, 1958. It was 524 metres high, which would have swamped the world’s tallest building, the Petronas Towers in Kuala Lumpur.
4) The biggest known earthquake in New Zealand was the 1855 Wairarapa quake. It measured 8.2 on the Richter Scale and shifted about 5000 km2 of land vertically.
5) Charles Richter, the man who invented the seismic scale, was a nudist. His wife disapproved of this so divorced him and moved to France.

Rockin' down Shake Highway 45

MT TARANAKI is soundly asleep, but you could still be shaken awake by a quake.
That’s according to seismologist Steve Sherburn, who is an expert on Taranaki’s tremors.
In the past 60 days there have been more than 30 shallow shudders on the coast, with about 25 of those in the Okato area, 26km south-west of New Plymouth, on the west coast of New Zealand's North Island.
Many have been too light to make the GeoNet website “recent quakes” section, but they do appear as splodges on a map that makes coastal Taranaki look like a teenager with severe acne.
New Plymouth looks worse, as if the pimples have become infected. While there has been less activity beneath the city, the quivers have been bigger.
Sherburn, from GNS Science in Taupo, says the cluster of quakes is normal for us. “The pattern that we see is fairly typical of what’s normal for Taranaki.”
That’s because of the Cape Egmont Fault Zone, which is a line of faults that run north-east and south-west off Cape Egmont. They are mostly offshore where there are no recorders, but the faults come onshore at the extreme west of the bump.
The fault belt heads towards Nelson and up towards New Plymouth, so the lines would look like 2o’clock on a watch face.
Our region is shaken between 200 and 300 times a year. “Some years there will be a lot more than that.”
New Zealand’s most active area is Matata in the Bay of Plenty, where there have been more than 700 earthquakes since November last year.
In Taranaki, we are having a normal year, says Sherburn, who has been one of Taranaki’s major fault-finders. A few years back he set up 70 seismic recorders around the region. For six months he monitored the movement of the ground and learnt something that will reassure those who fear our volcano could suddenly erupt.
In the whole time he took those recording, there were only three earthquakes under the mountain and they were “bog standard fault shakes”.
Sherburn is absolutely certain they had nothing to do with moving molten rock or gaseous liquids – nor have any quakes since.
“When volcanoes are waking up they produce a characteristic earthquake.”
These are, rather obviously, called “volcanic earthquakes” and their movement is not like a fault jolt.
“It’s more of a rocking than a sharp shaking,” he says.
It can, therefore, be picked up instantly by a seismologist, which is good news for those living in the shadow of Mt Taranaki.
“There is no evidence that it’s waking up,” he says. “Because we are not getting any now, hopefully when it does start to wake up, we will notice and, hopefully, get quite a long period of warning.”
But don’t start relaxing yet – there’s still the matter of the moving plates and our fault belt. Perhaps our surfing route could be renamed Shake Highway 45?

Wednesday, 16 May 2007

Time to tap into hidden power of waves

THE oil and gas may run out, but the surf won’t. Taranaki’s wild Tasman Sea (right) could be the next natural resource to be harnessed in the search for a renewable energy source.
In fact, the waters surrounding New Zealand are just waiting to be tapped to make electricity, according to John Huckerby, executive officer of the Aotearoa Wave and Tidal Energy Association (AWATEA).
The acronym is a Maori word that means “new dawn” or “new beginning”, which the group believes is appropriate for this emerging technology. The full title explains the two ways the sea can provide energy – tidal and wave power.
The latter applies to Taranaki, especially the exposed south-west coast.
There are three types of wave device design but only two would be viable for Taranaki, Huckerby says.
One is the Pelamis Wave Energy Converter, which is the world’s most advanced technology.
“Some people call them the sea snake,” he says. “They look like commuter trains.”
The other is called a point absorber device, which sits vertically in the water.
Both use the motion of the passing sea swell to produce electricity.
“Wave and tidal energy is sustainable, clean, available, reliable and forecastable, We believe that New Zealand can source a significant proportion of its new energy supply from marine energy in the medium term.”
Huckerby says wave power Down Under is already a reality.
“It’s not commercial yet, but that’s not far away.”
An experimental wave device has been tested in Lyttelton Harbour since November last year, he says.
Other countries have waded right in. Britain has spent more than £50m ($NZ135m) in marine power projects. Earlier this year, £4 million ($NZ10.8m) funding was tabled to enable ScottishPower to build the UK’s first wave farm. Four Pelamis devices, with a combined output of 3 MW, will be placed off the Orkney Islands (below, left).

The world’s first commercial wave farm, the Agucadora Wave Park in Portugal, will be established later this year, utilizing the Pelamis device.
“The New Zealand Government has recognized the potential for this country,” Huckerby says.
If and when wave power projects take off, Taranaki’s wave riders won’t lose their special spots.
“No, the surfing community can be rest assured that it is unlikely to have an impact on them,” Huckerby says.
“It would be a coincidence if a project was near a surfing break – surprisingly, breaking waves have already lost a lot of their energy. The sites for surfing and wave power generation should be mutually exclusive.”
Instead, our region could safely ride the wave of a new energy resource that won’t run out.
Interest for Taranaki, particularly with its strong marine-related industries, is growing.

FREAKY FACTS... This one's for Simon

THE dinosaur age is a passing phase.
It tends to hit kids, mostly boys, between the ages of seven and 13. Any longer and you could have a palaeontologist on your hands.
My husband wasn’t and isn’t a fan of the Rex family. He’s not an anti-evolutionist, it’s just that he doesn’t get the fascination with big beasts from millions of years back.
He prefers the Brutus maximums of the oval ball-throwing kind.
Our nephew in Lower Hutt, however, loves anything Jurassic. He can recite a whole list of spiny-saurus creatures from 213 to 144 million back.
In this family, we prefer their mythical look-alikes – dragons. But I was a follower of the Flintstones, although our Dino has always been a dog.
This week’s Five Freaky Facts are for Simon, and his mega-minded mates.
1) The word dinosaur actually means “fearful lizard”, and was first used by Englishman Sir Richard Owen in the 1840s when reporting on British fossil reptiles.
2) Not all dinosaurs were big. The carnivore, Compsognathus, which walked the earth about 131 million years ago, was about the size of a chicken.
3) The largest was the plant-eating Brachiosaurus, with a long neck and tail. It weighed about 31,480kg, stood 14 metres tall and was about 22 metres long.
4) In terms of life spans, we would playfully describe them as dinosaurs. Scientists believe that some dinosaurs lived for up to 300 years.
5) We know the movies Jurassic Park and King Kong are pure fantasy, especially because they mix their monsters. No Stegosaurus ever saw a Tyrannosaurus – the former having been extinct for about 80 million years before the new tyranny arrived.
Also, the Brontosaurus was a fossil before the T. rex appeared on the scene.

MAD SCIENTIST - Naked truth

Eureka! Eureka! – there’s a tale behind these famous words.
While reading a book about Galileo, I learnt the legend of Archimedes and his bath-time brilliance.
My husband looked at me amazed. “What, you didn’t know that story?”
There’s always a first time for learning something, and maybe I was just more focused on the phrase than the reason for the exuberant expression.
From now on, I’ll be the one looking down my supercilious snout at those who don’t know the Eureka! story. To save you that embarrassment, here it is.
Greek mathematician, physicist and engineer, known as Archimedes of Syracuse (287BC-212BC), came up with the principles of buoyancy while taking a bath.
The king of the day suspected his crown maker of adding base metal to his headpiece, but he didn’t know how to find the facts without having it melted down.
This got Archimedes thinking.
The answer to the puzzle came when he was getting into his bath and water slapped over the side.
He realised that an object could be measured by the amount of water it displaced.
If the king’s crown was immersed in water, then the water it pushed out could be weighed. Archmides was so delighted with his discovery he leapt from the bath and, as legend has it, streaked bare through the town shouting: “Eureka! Eureka!”
The sting in the tale for the crown maker was that Archimedes proved the king had been tricked.
But more importantly, the scientist showed that metals have different specific gravities, which can be measured against the density of water. So there it is – the naked truth.


WOMEN have a trivial secret that makes them brighter with the cycle of the moon.
Especially those under the influence of Libra.
This has nothing to do with astrology and everything to do with, well, sanitary pads.
Some advertising boffin decided that if men can peruse the paper and magazines in the loo, us women can read the adhesive strips from our monthly protectors to improve our minds.
There are hundreds more where these come from, and they are purely the domain of us dames.
Here are Five Freaky Facts females may find familiar:
1) The koala is one of the few land animals that does not require water to survive.
2) The brain is 74% water.
3) When glass breaks, the cracks move faster than 5000km/h.
4) To survive, most birds must eat at last half their own weight in food each day.
5) On a clear, dark night a human can see a candle burning 50km away.

MAD SCIENTIST - Newton's 'elixir of life'

Gravity man Sir Isaac Newton (1643–1727) has a lot in common with Harry Potter’s nemesis, Lord Voldemort.
Instead of focusing all his attentions on unravelling the theory of gravity, optics and laying the foundations for calculus, the Englishman had a long-time obsession with alchemy.
For more than 30 years, the Cambridge University academic sought the “philosopher’s stone”, also known as the elixir of life.
While this may sound like he wanted to live forever – and in a way he has through his scientific discoveries – Newton was chasing every alchemist’s dream. His aim was to turn base metals into gold or silver, a goal which remains the stuff of fairytales.
Newton was an incredibly focused thinker, who would sometimes lock himself in his laboratory for six weeks at a time, often forgetting to sleep or eat.
His experiments were also dangerous, especially when he was exploring the world of optics.
He once inserted a large needle “betwixt my eye and the bone as near to the backside of my eye as I could” to test another scientist’s theory that light was a pressure pulsating through the ether.
Thankfully for all of us, Newton didn’t suffer any lasting injuries from his self-inflicted tests, which now come with a warning – don’t try this at home.

Saturday, 5 May 2007

Bets Mt Taranaki blowing top in 50 years

IF betting agencies took punts on natural disasters, you’d be wise to put your money on New Zealand's Mt Taranaki blowing its top in the next 50 years.
You might not be around to collect the winnings, but your descendants would be toasting your foresight with an expensive bottle of champers, probably far from the poison ash fallout. Perhaps Paris.
Massey University scientists have fresh evidence the Egmont Volcano, as it’s known in geological terms, may have a history of violence even worse than previously thought.
So bad, that if it continues its destructive track record, there’s 50-50 chance it will act up before 2057.
Associate professor in statistics Mark Bebbington (left) has been calculating the odds based on a five-metre-deep core sample taken from Lake Umutekai, south-east of New Plymouth in New Zealand's North Island.
Imagine the sample as a standing pole with a series of horizontal stripes made up of alternating layers of ash and soil.
The ash tells the scientists when an eruption occurred and the soil in-between shows them how much time passed between volcanic events. The longest lull appears to be 450 years, while the shortest span is placed at 10 years.
Dr Bebbington says the ash at the bottom has been dated at 10,000 years old, while the top layer is just 1500 years old. The sample shows there have been 104 events in those 8500 years. But scientists know the mountain’s last blast was in 1854.
Unlike Split Enz, geologists and statisticians believe history does in fact repeat.
“Basically, volcanoes are recurrent systems,” Dr Bebbington says.
“The wild card is that we are saying that the past is the best model for the future.”
With that in mind, it appears Mt Taranaki could be in another long sleeping spell.
But then again scientists believed Mt St Helens was an extinct volcano. In 1980, the mountain proved, catastrophically, how wrong those experts were.
Not Massey’s mountain specialists. They know the 2518-metre-high cone is just biding its time to vent.
After examining the figures and working out a distribution system on that one core sample, Bebbington says there is a 33-50% chance of Taranaki becoming active in the next half-century. “That’s fairly conservative,” he says of the estimate.
That’s because there’s more. In fact, another core, this sample taken last year from Lake Rotokare, south-east of the mountain near Eltham.
“It appears there were quite a number of events in that sample that don’t correspond with the one from Lake Umutekai,” he says. What this means is that the chance of an eruption just rose – along with the eruption count from days gone by.
“My gut feeling is that there have been somewhere between 150 and 200 (volcanic) events,” Bebbington says of that 10,000-year period.
While the new numbers don’t go back as far as the 450-year slumber period, the ash deposits show that wind direction has a lot to do with reading the life-lines of volcanoes.
In other words, if the wind was blowing a different way during the volcanic explosion, the ash may have landed somewhere else.
The discrepancies between the two core samples show this.
But Bebbington says scientists are still trying to match up the geochemistry of the ash samples, so a final reading on the mountain’s fiery future is yet to be revealed.
Just know, there are sensitive seismic recorders all over the rising landmark, which is being (thankfully) stubbornly still.
There is movement though. “East off the end of Taranaki there’s some activity there,” Bebbington says.
These deep-earth rumbles may be a sign, a hint from down-under, that the sleeper is about to awake.