South Island Stone Collecting Trip, Part Two – Riverton to Kaikoura

Continued from Part One.

Next stop was Riverton at the very bottom of the South Island, where we were based for the next three weeks – many thanks to Helen and Ray for the generous use of their holiday home. We collected many beach stones from the Riverton area and from nearby Gemstone Beach at Orepuki. The weather was cool and windy at times but not bad enough to discourage stone collecting. We met a handful of fellow stone collectors at Gemstone Beach and exchanged greetings and stories. We also spotted dolphins swimming off the beaches at Riverton.  

While based at Riverton, we took a day trip eastwards to Waipapa Point, Slope Point and Curio Bay, the latter being well known for its petrified forest that is uncovered at each low tide.

One day we walked the Long Hilly Track through an old gold mining area near Orepuki. This included part of the 40 kilometre long Port’s water race, built in the 1870s and 1880s with the help of Chinese miners. We visited the Riverton Museum and found an excellent display on the Chinese goldminers. On a visit to the Southland Museum in Invercargill, we saw a natural history room that included a lot of local geological displays and information.

On the trip north, on the way home, we stopped off to see the Moeraki Boulders in North Otago. Some sea mist came down even though it was the middle of the day. The boulders are large spherical rocks, concretions that have been exposed through shoreline erosion from coastal cliffs. They consist of mud, fine silt and clay, cemented by calcite. The degree of cementation varies from being relatively weak in the interior of a boulder to quite hard at its outside rim. The boulders are cracked and eventually fall apart after having been exposed for some time. 

A day was spent at Birdlings Flat, near Christchurch, where we collected quite a few stones for polishing. We walked to the point where the stony beach meets the volcanic mass of Banks Peninsula, briefly disturbing a resting seal. The tide was low enough for us to look at the stones in the small bay past the seal. 

We also took the opportunity to visit Akaroa on Banks Peninsula where we saw thick clouds rolling slowly down over the hills.

The road further up the east coast of the South Island, through Kaikoura, was open – it had to be rebuilt after the November 2016 magnitude 7.8 earthquake as well as additional landslides caused by recent storms. So we were able to view the earthquake aftermath, including the land that been raised out of the sea. Some parts of the coast were uplifted by six metres. One of the places we visited on the Kaikoura peninsula was Point Kean, well-known for its seal colony. A large area of many hectares/acres now lies dry where it once was under the sea. 

Then it was home across Cook Strait, a choppy but not uncomfortable crossing.

 

“Great Wall”

Seeing this great rupture in the landscape caused by the recent Kaikoura earthquake, and how it makes people feel small and feeble, brought to mind the song, “Wall of China/One Man”, by the Scottish group Runrig. 

[Up-date: TV item on the earthquake features, including the wall-like rupture, as tourist attractions in 2023 – see here. At 1 minute 6 seconds, on the earthquake; at 1 minute 39 seconds, on the earthquake and contemporary tourism; at 2 minutes 11 seconds, on the “great wall”.]

In the song, the Great Wall of China is used as a metaphor for struggling against great odds, one person with great determination doing something important though small in the face of greater countervailing forces – “only the meek can break the strong”. It has been stated that the song refers to a man on a Scottish island building his own road because the local government never got round to doing it.

They say the wall of China’s seen from the moon
They keep building empires to immortal fools
But where the world goes small you stood alone
To face Goliath and the might of Rome

Where the rock sets hard your arms hit strong
Digging out your road ten thousand paces long
Fragments of survival in the driving rain
With the blood and tears that bear your name

On and on, the meek the strong
On and on, the meek the strong

They built the wall of China with a million men
Thought that broken promises would wear you thin
But they didn’t count on things they couldn’t see
One island man with heart of steel

On and on, the meek the strong
On and on, the meek the strong
On and on, the meek the strong
On and on, the meek the strong

One man to change the world
One word to bring it down
One stand to right a wrong
Only the meek can break the strong
Only the meek can break the strong

A version from YouTube with photos and information on the Great Wall of China itself:

Update on Kaikoura Earthquake Impacts

The significant coastal uplift that resulted has been confirmed. Nasa have produced “before” and “after” satellite photos:

and GNS Science’s Kelvin Berryman has illustrated aspects of the fault line changes on the ground:

Dr Kate Pedley, a University of Canterbury geologist, has walked along part of the fault-line and taken photos of the small and large impacts as can been seen on the landscape:

Drone footage of part of the rupture:

In one place, part of the landscape has opened up and dropped, creating a large gully:

It was initially thought that the freshwater pool that acted as a seal pup nursery could have been buried or destroyed. This investigation found it still largely intact:

 

 

Kaikoura – Whales, Dolphins and Seals, 7.8 Magnitude Earthquake, Landslides and Raised Beaches

In February this year, our car trip around the South Island included a drive north along State Highway One from Christchurch to Kaikoura and then on to Picton to catch the car ferry across Cook Strait to Wellington. It was after our visit to the limestone landscapes around Duntroon that we made our way to Kaikoura, a small coastal tourist town. There we took a whale-watching boat trip during which we saw a sperm whale (a great sight!) and hundreds of dolphins diving and leaping about (an unforgettable sight!). The photos below were taken by Petra:

After the whale and dolphin sightseeing, we walked along the Kaikoura foreshore near our motel and collected a number of stones for future polishing. The next day, we continued our drive north, stopping after about 25 kms at Ohau Point to view seals on the rocks below the road and to walk inland up a stream to a small freshwater pool below a waterfall which is known as a seal pup nursery.

The seal pup pool was empty when we visited (click on the link below and then click to start the video to see a short video clip of seal pups in the pool).

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Nine months later, on Monday 14 November, just after midnight, I felt the bed shaking lightly but persistently for what seemed to be quite a long time. I realised that an earthquake was occurring somewhere in New Zealand, some distance away, and that it was likely to be a big one. It turned out to be a magnitude 7.8 earthquake. Its epicentre was about 15 kilometres north-east of Culverden in Canterbury, and 60 kilometres south-west of Kaikoura, at a depth of 15 kilometres. The earthquake ruptured on multiple fault lines in a complex sequence that lasted for more than one minute. It was New Zealand’s second largest earthquake in recorded history, though only two fatalities have been associated with it. Its impact on Kaikoura has been devastating. Multiple very large landslides occurred along the coast, burying parts of State Highway One and the railroad track, and portions of seabed near Kaikoura were lifted at least two metres along the shore. Click the link below and then click to start the video for brief video footage of uplifted beach.

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Source = Stuff Report

Massive landslides caused by the earthquake and its multiple aftershocks appear to have wiped out the seal breeding ground at Ohau Point, just weeks before the start of pupping season. 

It was fortunate timing, however, as many would have been out at sea feeding at the time. It was unlikely there were pups at the waterfall at the time of the earthquake, according to a Department of Conservation spokesperson. The waterfall was not yet accessible, so it was unclear if it remained intact, but due to the surrounding damage it was unlikely to have survived. “Those seals generally come back to the area where they were born. They’ll go in there and it won’t be like anywhere they recognise before, so they’ll probably just go and breed on other parts of the coast.” A group of University of Canterbury students had been studying the seal colony and hoped to use thermal imaging to check the population. “We’re hoping to get up there within the next couple weeks,” said Dr Sharyn Goldstein, who is supervising the students. “Apparently there has been a big landslide, and at this year they’re pupping and pregnant so it might have quite an effect.” (Source = Another Stuff Report.)

The Kaikoura earthquake lifted long strips of coast out of the sea on Monday morning, in parts as high as two metres. The following are before/after photos of an area about 50 kms north of Kaikoura town (source):

sat1
Waipapa Bay, about 50 kms north of Kaikoura, before the earthquake, March 2016
sat2
After the earthquake

The uplift of the by the earthquake has stranded many crayfish and paua (a shell fish). 

See this Stuff Report for more, and see The Spinoff for a discussion of the coastal uplift along the Kaikoura shore.

As a beach-stone collector and polisher, it is sobering to see the forces and processes at work that produce the rocks and the coasts that we spend time at when pursuing this hobby.