Norfolk sand: Has a colossal experiment worked? | Hacker News Reader

Norfolk sand: Has a colossal experiment worked?

bbc.co.uk

64 pointsasplake49 comments

This is sometimes called "beach replenishment". It's popular with owners of beach front houses, but the cost-effectiveness of moving all that sand is questioned.[1]

There's an amusing case on this. If the U.S. Government widens a beach by adding sand, is the new land public property? The U.S. Supreme Court said yes, much to the annoyance of some beachfront property owners.[2] If you want to extend your own beach, buy your own sand.

[1] https://granthshala.com/jersey-shore-beach-widening-is-a-was...

[2] http://www.cnn.com/2010/CRIME/06/17/scotus.property/index.ht...

The country of the Netherlands just about owes its current existence to the practice of beach nourishment. In a lot of cases it is the most economical and least impactfull way to defend an eroding sandy coast. So called hard solutions (rock and conrete based) mostly fail within a few years/decades. And what is the point of living along the coast if there is no beach anyways?

Note that it is well understood that beach nourishment is a recurring thing, and thus will be planned/budgetted for. Any other kind of coastal defence structure will also need (a lot of) maintenance which is oftentimes neglected, leading to catastrophic failure (sudden collapse/breach). A sandy coast can certainly fail to provide adequate protection, but it is rarely sudden breach/collapse/rupture.

The article notes that this is the first time this kind of thing has been done in the UK. And indeed, the Netherlands has been doing it since about a decade: https://en.wikipedia.org/wiki/Sand_engine (also mentions the Bacton gas terminal, as in the article).

Germany has been doing it for its North Frisian islands sind 1972. The key words: has been doing. It works, but in most cases the sea keeps taking away the sand and you keep having to put it back.

The Dutch have been doing sand suppletion since similar times. This "sand engine" is supposed to be a more advanced, long-term solution.

> the sea keeps taking away the sand

Where does it go?

Mostly to the bottom, but some remains suspended in a saline dihydrogen monoxide solution.

Saline dihydrogen monoxide?

Don't know if you're meming or trying to sound smart.

Just say seam water man

I had the same question and I’m also not sure why this is getting downvoted. I’ve never seen water referred to that way even in scientific contexts. Is it supposed to be a joke?

Yes, it's a joke: https://en.wikipedia.org/wiki/Dihydrogen_monoxide_parody

Not the OP here, but the answer seems like an obvious “yes” to me.

The Frisian Islands grow on the lee and shrink on the windward side. As a result they are gradually moving eastward.

It moves along the coast mostly, until it is either blocked by e.g. a port entrance breakwater or in a shallow estuary, or it is washed up to shore and gets blown into the dunes

The ocean is big.

It also notes two Dutch companies involved in (and 'mastermind'ing) the project.

Key point for me was "It’s not a permanent solution, however - the sand is expected to last for about 15 years." It doesn't say whether the full £20m spend will be needed every 15 years though, but it sounds like it just buys more time to move the critical infrastructure further inland.

Here’s hoping that they can close the gas terminal by 2035 and not replace it.

Really interesting! It's common to see s/groins/groynes/[0] installed on many UK beaches, which helps when the shore is also small rock/pebble. But this seems more dynamic and natural, I hope it works in the long term!

[0] https://www.seawallprosfl.com/wp-content/uploads/2017/04/max... and https://www.seawallprosfl.com/ways-to-prevent-beach-erosion/

> It's common to see groins[0] installed on many UK beaches

In the UK, we prefer to call them groynes. A groin is something quite different...

haha oops! Corrected.

It would be better if they had used olivine sand. That would pull CO2 out of the air, and protect the coast.

We are going to have to be doing that, by the millions of tons. But it will be pointless if we continue pumping as much CO2 into the air.

Yeah, that was my first thought too. I was actually pretty excited by the title, I thought this would be about olivine beaches. Pretty disappointed when I read the article.

Measuring success against geologic forces in a timeframe of single-digit years is incredibly foolish.

I imagine they're using the data gathered within this timeframe to extrapolate into the future, and not just calling it a day like you suggest.

Who pays for these fixes to greenhouse gas emissions? Surely it's the greenhouse gas emitters?

Society writ large, usually.

For a fun comparison this amount of sand is about 7% of the volume of Three Gorges Dam.

> The sand, engineers believed, could work with the wind, waves and tides to protect both the gas terminal and villages nearby.

Sorry for the snark, but as if the village had anything to do with this project getting approved.

> two million cubic tonnes

The British really do have the weirdest units.

Cubic tonnes are technically a real and valid (SI even, ish) unit of measurement (for example the fundamental evaporation rate of a black hole via hawking radiation is on the order of 100 million cubic tonnes per second), but I think in this case they're just outright wrong.

What does cubic mass mean?

The time it takes a black hole to evaporate is proportional to the cube of its mass. If you graph mass-cubed versus time, it decreases linearly at about 100 million cubic tonnes per second. The actual mass decreases at a rate that's inversely proportional to the square of the mass.

Interestingly this may be a typo as the article mentions cubic meters. But wiki says cubic tons is a measure of volume that is obsolete in UK and mostly used in the US

It really irks me that journalists cannot make the slightest effort using proper units. Here I understand they meant 2Tm³ (terameter³).

Feel free to put in parenthesis the number of British buses or American football pitches, for the older folk from UK and USA if necessary.

But please use units that are universal and scientific!

If you're going to be pedantic, please put in more effort in identifying the correct unit of measurement, whether it's feet, meters, leagues, or terameters.

A terameter is a unit of length equal to 1 trillion meters.

A cubic terameter is 1x10^36 cubic meters.

2 million cubic meters would be something like: .000000000000000000000000000002 cubic terameters

Or: 2e-30 terameter³

If you're wanting minimalconversion, the amount comes to 2 cubic hectometers.

Indeed. 2 million tonnes == 2Tg. 2 million metre³ == 2hm³. The unit in the article is "cubic tonne". I mixed the whole thing without thinking. This is maybe adding weight (what a pun) to my original point though. Using the proper unit at the source.

No matter how you parse it, it cannot be 2Tm³. The most generous reading would be "two trillion cubic metres" rather than two million. It could also be read to mean that you want to cube a terametre.

We should make some islands with this technology. Maybe it could help solve the housing crisis.

We could ask China about it, they have been practicing it in the South China Sea.

It’s weird, in Florida we do this almost every year. It’s not a big deal.

This is a newer technology, intended to replace the once-every-few-years suppletions with one that only needs to be done every 20 years or so, thus causing less overall impact on the environment. The already existing one before the coast of South Holland was evaluated fairly recently, and it looks like it will last even longer than designed.

Interesting. What’s different about it?

Basically they dump a lot more sand in a strategic location and shape so that, if I understand correctly, the sea will make it flow to where it is wanted. https://en.wikipedia.org/wiki/Sand_engine

> Bacton Gas Terminal was getting ever closer to the cliff edge as the coast eroded

That was a problem that was getting close to solving itself. Now I understand why so much effort was expended.

Thermal coal prices are at record highs and production is rising. Part of the problem is natural gas prices spiking to record highs.

Closing down gas production right now will not solve any problem except the balance sheets of the coal industry.

That's a false choice and a misframing. The problem is we are boosting production of dirty fuels to meet energy demand recovery.

If you reduce gas production, you will increase coal usage. That is what will happen. That is what does happen.

Yes, but in free markets. They are both dirty fuels, so this shouldn't be a free market decision. This is something we have to do collectively that the market participants won't choose to do on their own.

You will even increase coal usage if gas prices increase. The market adjusts.

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