New Zealand is faulty

New Zealand is faulty! Geddit? But really, if I’m writing about New Zealand-related stuff, I should probably mention earthquakes. As it turns out, there is a downside to living in this country, and it looks like this:

Image

Wikimedia Commons

New Zealand is only here because we are sitting on top of the edges of two massive tectonic plates. Where they meet, they are crushing together with such force that they are pushing the land up. If you want to get technical on the tectonics, this particular fault is called a right-lateral strike-slip fault. No, I had no idea what this means either. But I did some research, just for you. It means that the fault also caused the land to move on the horizontal plane, as well as vertically. The right side of the fault moved south, and the left side moved north. This is why the same fossils have been found in Nelson and Fiordland:

Image

The existence of the Southern Alps is testament to just how much force the plates are exerting. The mountains rise sharply from the sea on the west coast, while the Canterbury plains only exist east of the mountains due to sediment runoff being dumped by rivers.

The freaky thing is, the fault that caused the Canterbury earthquakes wasn’t the Alpine fault at all, but a little offshoot that scientists didn’t really know much about until it blew.

Though this land is pristine and full of natural beauty, it is only rugged because of geological activity. This geological activity continues to this day.

We have certainly not seen the last quake.

When (yes, I said when) the Alpine fault goes, it’s really going to go. Like, really. Hopefully we will make it out to tell the tale.

Are you ready?

Image

Wikimedia Commons

Advertisements

A sign from God…or…?

Don’t you hate those moments when you wished you had a camera, but you didn’t. Yeah, well had one of those moments recently, when I witnessed a phenomenon that I’d never seen before. It was pretty amazing, but I didn’t have a friggin camera, so you’ll just have to believe me.  I was high on a mountain side above lake Wakatipu, near Glenorchy. We were hoping to get a decent view from the top, but we were climbing through cloud for most of the way. It wasn’t looking likely that we were going to break through the top of the clouds. It’s a bit demoralising, when you’re busting your backside to get to the top of a mountain, and all you get to see at the top is this:

Image

Wikimedia Commons

But the clouds started to clear, and like a ray from heaven, the sun broke through. The tip of the mountain we were standing on was suddenly a small island amongst a sea of clouds, and I witnessed a holy revelation. (Well, that’s how people have historically interpreted this phenomenon). 

With the sun behind me, my shadow was being magnified to make me a giant, and was being cast onto the clouds below me. Surrounding my body was a perfect, circular rainbow. It was like there was a holy halo surrounding my body.Image

Wikimedia Commons

I found out later, that what I saw was called a Brocken Spectre. It is named after Brocken, the highest peak in Germany’s Harz Mountains, where it has often been witnessed.  In reality, the magnification of the shadow is an optical illusion, but because the sun is casting your shadow onto the clouds at an oblique angle, it makes you look like a giant. Also, the shadow is generally on clouds that are nearby, but you are comparing it to far-away objects, such as the tips of other mountains, so it looks huge. The shadow appears to move, which adds to the freakiness of the whole phenomenon, but it is just the clouds moving.

The rainbow is known as a Glory, and radiates out from the head of the shadow. There is still debate amongst physicists as to how the glory actually happens, but is thought to be due to classic wave tunnelling. This means the light is cast through air inside each water droplet, and is refracted backwards. From the perspective of the person making the shadow, a full rainbow is visible. 

This phenomenon has been referenced countless times in literature and songs, and has often been interpreted as a sign from God, or as ‘Buddha’s light’. I prefer to appreciate the fact that it is a phenomenon that only a few lucky people get to witness, through being in the right place at the right time. 

Rats: Telling the ‘tail’ of Maori voyages across the Pacific

The story goes that the Maori people came here in waka (canoes) from a land called Hawaiki. We don’t know for sure where exactly Hawaiki is – we know it’s somewhere in Polynesia – nor where the Maori peoples’ ancestors originally came from.

It is thought that people started to colonise ‘near’ Oceania around 40, 000 years ago, that is the area closest to Asia and Australia – New Guinea, and the Solomon Islands. They gradually began to move east, into ‘remote’ Oceania – Vanuatu, Fiji, Tonga, Samoa and beyond. Their progress was complex, slow, and involved lots of interactions with other populations along the way. This makes it hard to figure out exactly where the ancestors of Pacific people came from. Image

This map shows approximate Pacific migration routes and times. Source: Wikimedia Commons

A piece of the puzzle comes from an unlikely creature – the Pacific rat, kiore (Rattus exulans). Image

Wikimedia Commons.

Kiore came across the Pacific with the Maori people. The rats were probably brought deliberately, because they were a good source of protein. They are bigger than ship rats (Rattus rattus), and don’t carry disease, so they made for a good feed. The rats did well when they got to New Zealand, because there were plenty of animals with no defences to feast upon.

A study by researchers from the University of Auckland looked at the genetic history of kiore, as a way to gain a better understanding of where Maori ancestors came from. Mitochondrial DNA is passed down the maternal lineage of rats (from mother to daughter) without getting mixed up, like regular DNA does. The rate that mitochondrial DNA mutates is also very regular and predictable. These two features of mitochondrial DNA (that it is preserved from mother to daughter, and that mutations are regular) meant that scientists could look at distinctive sequences, to compare the relatedness of rats from different parts of the Pacific. Image

Wikimedia Commons.

Closely related kiore will have the most similar mitochondrial DNA, and mutations can be tracked back through generations, by comparing modern kiore DNA to that of ancient bones.

What they found was that the rats were from three distinct populations. This suggests that there may have been three groups of people, which may have interacted as they migrated around the Pacific.

We still don’t really know where the Maori people originally came from, but at least we have a rough idea of their migration paths from Asia to near Oceania, and eventually to their settlement in the remotest part of remote Oceania.

Guess what everyone? It’s snowing!

Ohmygodohmygodohmygod it’s SNOWING!!

My facebook newsfeed is doing a fine job of keeping me (as well as anyone who may be living under a rock) informed on the weather. I have so far counted approximately 60 snow-related statuses, and they just keep coming.

But why is snow such a novelty to New Zealanders?

Well, because we don’t see it very often.

Here in Dunedin, we live at a similar latitude to the Swiss Alps and the northern USA/southern Canada, where snow is just a normal part of life. Gosh, they’d laugh if they could see our pure joy at 5cm of slush.  But it’s a big event!

Image

Photo: J Goodwin

On continents during winter, the low sun and short days allow cold air to build up. Without the regulating effects of large bodies of water, or offshore prevailing winds, the continent gets really cold.

New Zealand doesn’t get these extreme continental seasons, because it is an island with an oceanic climate system. The ocean acts as a buffer, which regulates temperatures – making our winters cool, rather than cold (try telling that to my toes!), likewise, our summers are warm, but not hot.

Because the temperatures are not extreme, native plants and animals can stay active year round. Trees don’t lose their leaves, and animals don’t need to hibernate.

But this is a bit of an oversimplification – New Zealand’s climate is a complex beast. It is a long and skinny country, so the top of the North Island is subtropical, while the bottom of the South Island is temperate.

The Southern Alps, running down the spine of the South Island are an extreme alpine environment (Read: bloody cold in winter).

West of the Southern Alps is very wet, because the clouds need to drop their rain before they can blow east across the mountains. This makes the East Coast very dry – Canterbury is known for its maddening nor’west winds, which whip up dust and drive everyone crazy.

Image

For some reason, New Zealand winters feel just as cold as European winters. I have a theory on this, which I think is very scientifically sound:

European houses are centrally heated and well insulated. New Zealand houses are not!

And now this blog must come to an end. It’s a bit short, but I have to go skiing quickly before the snow melts!

Cows can kill Polar Bears

New Zealand has 10 million cows and 31 million sheep – That’s 7 sheep for every person (it used to be 20 sheep per person!), or to use the official unit of measurement: a crap-load of farm animals for one little country.

Cumulatively, New Zealand’s crap-load of farm animals belch up quite a bit of gas. In fact so much, that they are New Zealand’s primary contributors of greenhouse gas.

Image

 

This flatulent problem sparked debate in parliament a few years ago, as to whether we should introduce a “fart tax”. This would have put money into research to counter these gas emissions – what with climate change and all that. Farmers, who stood up and protested in true farmer fashion, did not meet this proposal kindly. – Mud was thrown at politicians, and one opposition MP drove his tractor up the steps of parliament (I wonder if he drove it all the way from his farm into central Wellington?). So the lawmakers clearly got the message that a fart tax would not fly in New Zealand, and they scrapped the bill. 

But did you ever wonder why cows are so gassy?

Well it’s because of the way their digestive system works.  The tough cellulose that lines each grass cell is very difficult to break down into bits that can be digested. That’s why humans can’t eat grass.

But cows and sheep have “4 stomachs” (really, this is one stomach, with 4 compartments) which contain rumen bacteria – this is why cows and sheep are known as rumens.

The grass is partially digested in the first compartment before it is regurgitated back up and chewed again. Mmm. This regurgitated grass is also called cud, hence the term ‘chewing the cud’.

Once the cud is well mixed with saliva, it passes through to the rest of the stomachs where it is fermented by the rumen bacteria, which breaks the nutrients down into a form that the cow can absorb. A byproduct of this fermentation is methane gas. The cow mostly burps it up but occasionally a build up occurs, which makes for an explosive cow. But that is another story altogether.

Image

 

Without these bacteria, the cow wouldn’t survive – it would starve. Without the cow, the bacteria wouldn’t survive – they’d have no home and nothing to eat. So really everybody wins…except for the atmosphere. And polar bears.

And that is the story of New Zealand’s problem with flatulence.  

Cows burp up methane, this goes into the atmosphere, causes the climate to warm, causes ice to melt, polar bears need ice, polar bears die.

Killer cows. 

Pounamu: Treasure from the first quest to Middle Earth

When my dad was a kid he found these toki (adzes) in a paddock on his family’s farm in Western Southland. They are Maori tools, made out of Greenstone/Pounamu, a relic of pre-European settlement in the South Island. Image

Maori came down from the North Island to collect Greenstone for tool and jewellery making. The greenstone from the South Island was so important to them that they named the island after it – Te Wai Pounamu – Waters of Greenstone.

Expeditions for Pounamu involved traversing high mountain passes, walking hundreds of kilometres, and carrying huge amounts of heavy stone. They were really the first people to go on a quest for treasure through Middle Earth, and they didn’t have ponies or wizards to help them!

The Routeburn Track – one of New Zealand’s famous ‘Great Walks’, hiked by thousands of people each year – was originally formed as a Pounamu route from the West Coast to the much more inhabitable East.

Image

The Humboldt Mountains, terrain traversed by Maori on Pounamu expeditions. Source: Wikimedia Commons.

Pounamu was formed under intense heat pressure, 10km under the Southern Alps. The hot fluids and pressure caused a chemical reaction between greywacke (sedimentary rock) and dunite (volcanic rock), which produced narrow bands of pounamu. The uplifting forces that pushed up the Southern Alps also brought Pounamu to the surface. Erosion from water and glaciers has broken away the much softer surrounding rock to expose chunks of Pounamu. These rocks are rarer than gold, and much harder to spot. To the untrained eye, uncut and unpolished Pounamu looks just like any other rock.

In 1997, parliament declared all Pounamu in its natural form was now the property of the South Island Maori tribe, Ngai Tahu. Since then, they haven’t mined it, which means it’s pretty hard to get your hands on these days. The demand for it far outstrips supply, which has made it far more valuable than Canadian and Chinese Jade, meaning a lot of tourist souvenirs aren’t actually made from New Zealand Pounamu at all.

Traditionally, Pounamu was used for tools, as a symbol of chieftainship and also as a peacemaking agreement between tribes. Jewellery included Hei Tiki (made famous in the 90s, when Air New Zealand issued passengers Hei Tiki made out of plastic – at the time a cultural faux pas, but now considered a proud, kitsch symbol of Kiwiana).

Image

A Pounamu Hei Tiki. Source: Wikimedia Commons

The origins of Hei Tiki aren’t really clear, but some say it is in the form of the first man, Tiki. Others say it is female or sexless. There have been a few instances where previously infertile women have given birth after being given Hei Tiki.

Today Pounamu is valued as a symbol of national identity by all New Zealanders, often worn as a pendant, like these ones of mine:Image

Kiwis around the world can be spotted wearing Pounamu, a small token to remind us of home.

 

————————————————————————————————————–

The Maori version of events from the the Ngati Waewae iwi (tribe):

One day, the taniwha (supernatural being) Poutini comes to Tuhua (Mayor Island) in the Bay of Plenty. There, he sees a woman bathing – the beautiful Waitaiki. Enchanted, Poutini kidnaps her and takes her south. At various points along the way, he lights a fire to keep her warm.

When Waitaiki’s husband, Tamaahua, discovers she is missing, he pursues Poutini and Waitaiki. He is aided by a magic tekateka (dart) that shows him the way.

Wherever Poutini has lit a fire, Tamaahua finds a valuable source of stone. The journey takes him past the Arahura River on the South Island’s  West Coast as far as Piopiotahi (Milford Sound)

Finally Tamaahua retraces his journey back to the Arahura River. There, he discovers Waitaiki turned into smooth pounamu in the riverbed.

Poutini, sensing Tamaaha close behind, has transformed Waitaiki into his own essence. He has then slipped down the river and out to sea.

This guy flew before the Wright Brothers

Here’s a guy that never got much recognition for a pretty big achievement: Richard Pearse, the first person to successfully(ish) build a flying machine.

Image

Wikimedia Commons

Unlike the wonderfully pompous Brits in “Those magnificent men and their flying machines”, Pearse was far from magnificent. He was pretty eccentric (aka mad), and eventually ended up going off his rocker.

Makes for a good story though.

His flying machines were “successful” in that they flew – kind of. According to eyewitness accounts, he ended up stuck in hedges more often than not, meaning he only get about 4 or 5 metres off the ground. To be honest though, I wouldn’t want to be any higher than that in in a contraption like this! His flight was far from controlled. But still, it was flight. Image

Replica of Pearse’s flying machine in Timaru Museum. Image from Wikimedia Commons

Pearse flew his machine around 9 months before the Wright brothers took to the air. His best attempt took him about 1000 yards, flying alongside the Opihi River in Canterbury, before the engine overheated and he crash-landed in the dry riverbed.

The engine in his plane was 15 horsepower. If you consider that an average modern car is about 200 horsepower, then it really is amazing that his machines had enough power to take to the air at all. This engine was good enough to lift him, but not enough to control his turning.

If the wings on his plane had been designed with aerofoils, then it may have been a lot more efficient, which would have allowed him more control. Cross sections of modern plane wings, bird wings and dolphin flippers are all shaped like this, with a rounded front edge, and a tapered back. Pressure difference created as air (or water) flows past gives an aerofoil shaped wing more lift and less drag.

Image

Wikimedia Commons

Pearse never really spoke out about his machines, and certainly wasn’t seeking recognition for his work. There are no documented newspaper accounts from the time and he never received recognition during his lifetime.

It seems that he was pretty keen to keep his machines a secret, because later in life, he became reclusive and paranoid that foreign spies would recover his work. He was admitted to Sunnyside Mental Hospital in Christchurch, where he died in 1953.

Paua to the People

Ahh paua. Used to make shimmering blue-green eyes in the most beautiful Maori carvings.  A classic Kiwi icon in art, jewellery, and is of course used to make the tackiest souvenirs. Image

Wikimedia Commons

Fred and Myrtle’s Paua house at Bluff was always a must-see attraction until the shells were taken away.  They’re now in the Christchurch museum which doesn’t have quite the same charm as the real house, but it’s still kitsch Kiwiana at it’s best! Image

Photo from here

Paua also make a good feed. Personally I think they taste like cooked jandals, but apparently that’s because I either have no taste, or I didn’t tenderise them properly (you mean 30 minutes of bashing them with a wrench isn’t enough???).  If you’re still confused as to what they actually are, they’re big marine snails, also known as abalone. Image

Wikimedia Commons

There has been an outcry recently about a proposal for Otago’s protected coastline to be opened up to commercial fisheries, because this is prime paua collecting territory. A group called Paua to the People (geddit!) was formed in opposition to the proposal. They say that if commercial divers are able to harvest these paua, then they will take them unsustainably and leave none for the little guys. They might be right.

500km of Otago’s coastline is already open to these companies, and they have pretty much screwed it up big-time. They’ve taken too many big paua, leaving very little to collect later. But rather than coming up with a way to manage their areas sustainably, they want to open up some of the remaining 165km of coastline for commercial harvesting.

Naturally, recreational divers, and everyone else with a bit of common sense and no monetary interests in paua has said that this is a terrible idea, because this solves nothing in the long term. There is nothing to stop the companies harvesting these areas unsustainably too, and once these paua are gone – some say this will only take a week or 2 – then they’ll be in the same predicament as before.

But you know what, that’s capitalism kids. I’m no expert on economics, but it seems that the big businesses reap the short-term rewards, and then wonder what to do once they run out of stuff to sell.  I suppose it adds insult to injury that the commercially harvested paua are sold overseas too.

Submissions on this proposal have already closed, so I guess all there is to do now is hope that the Pauas that be (sorry, terrible pun) choose to do the right thing.

A river that runs backwards

So we all know that New Zealand is unstable. Literally. As anyone from Christchurch will assert. So it shouldn’t really come as a surprise that with all this up-ing and down-ing and to-ing and fro-ing of the land, that a river has changed direction. No, I don’t mean there is a river that runs uphill, but rather that the land under a river has shifted enough to make it turn around. That’s pretty crazy stuff. Like, at some stage in our geological history, the Nevis River has just stopped and then carried on in the other direction. Cooler still is that it is part of this river system: (Although the pillars of the Kings weren’t there the last time I checked).  Image

Picture from here

So how do we know this?

It’s thanks in part to these guys who I wrote about in my last blog:

Image

This story involves 3 rivers:

–       The Nevis (which changed direction)

–       The Kawarau (which the Nevis now runs into)

–       The Mataura (which the Nevis used to run into)

(and I suppose I should mention that the Nokomai stream is the part of the Nevis which continued flowing the same way)

ImageImage

And the story involves this fish: Image

Photo from here

If there were an award for the best naming of a species, this would certainly be a contender: Galaxias gollumoides , aka the Gollum fish. There is even another very closely related species called the Smeagol fish.

Zoologists at the University of Otago have found that the Gollum fish in the Nevis have relatives in the Mataura River (to the south) but not in the Kawarau River, which the Nevis currently flows into. This supports the geologists’ evidence that in the Pleistocene (2 million-ish years ago) the Nevis used to run south through a valley between the Garvie Range and the Remarkables Range (the jagged mountains behind Queenstown).

As the mountains on either side grew, they pinched off the valley the Nevis was in. At the same time, erosion blocked off the Nevis, and caused it to run back the other way.  This isolated the Gollum fish in the Nevis from the Mataura river where it used to run. The Nevis population has since diverged from the Mataura population, but is still closely related. Image

Species that today are found in the Kawarau are not found in the Nevis, yet are found in other tributaries to the Kawarau.

P.S. If you want a closer look at the Nevis River, then this is a good way to do it!Image

Photo from here

“You ate my babies and didn’t even know it” – NZ’s Galaxy Fish

This is the Bacon Street Creek on the Otago Peninsula:

Image

I spent half my childhood in this creek, going on “expeditions” on the walk home from school – building dams, catching tadpoles and going “mining” in the pipe. For all the hours I spent in the creek I never had a clue there was something else living there.

These guys:

Image

Photo from here

This is a giant kokopu, a species of galaxiid, which are native freshwater fish. The name is kind of strange, but someone thought their patterned skin looked like stars in the galaxy, so they named the fish after it. I took the liberty to simplify it further to “Galaxy Fish”.

Image

A lot of kiwis have never even heard of galaxiids, but have eaten their babies!

There are 5 species of galaxiids (there are about 28 altogether) that go out to sea just after they hatch from their eggs. They spend their larval stage eating plankton, before swimming back into rivers as whitebait.

Image

Photo from here

If the whitebait manage to run the gauntlet through the nets, then they go way upstream to grow up.

Of those that don’t make it past the nets and end up in your fritter, 80% are probably inanga, while the other four are giant kokopu, banded kokopu, koaro, and shortjaw kokopu.

Image

Wikimedia commons

Galaxiids are on the whole endangered. Some are as rare as Kakapos, but we don’t really know that much about them. Part of the reason is that they are so secretive, but also because they are not a sexy species to protect – we all love to help save cute fluffy things like kiwis, but what about the slimy galaxy fish?  Image

But what they lack in sexiness, they make up for in awesomeness:

They can climb better than you –

Image

Photo from here – Koaro whitebait climbing a barrier designed to stop fish from moving upstream.

They can also tell us about New Zealand’s history. In my next post, I’ll talk about how these fish have helped us figure out the mystery of a river that flows backwards, and how they stopped a whole valley from being flooded.

But these little fish are in trouble, mostly because of trout, which eat and out-compete them.

Image

Wikimedia commons

Trout are pretty neat too, and we like them because they bring the tourists here who in turn bring their big fat wallets. Because of the trout fishing industry, the organisation Fish and Game make sure our rivers are clean and healthy for the fish.

We don’t want to get rid of trout at all, but just from the small streams that aren’t worth fishing for trout in.

In Otago, there are heaps of really little streams with galaxiids in them. The streams are tiny and have changed course over time, splitting up populations of galaxiids and causing them to diverge into different species. Some of these species are super rare, so it would be a shame if trout got in and wiped them out. They’ve already invaded most streams, but it’s worth the effort to take care of the rest.

Galaxy fish are awesome.

Image