[SA Chris]

Why dead legs are deadly. From a corrosion perspective.

[moose]

Aye, sulphide corrosion is a right bugger in "dead" pipework.  Interestingly (to me anyway) I think there's an analagous non-microbial process that occurs in "dead" domestic settings, when central heating systems are pressure tested but then left full of static water before use.  You then get pitting corrosion where areas of passivation are stripped but not re-oxidised, resulting in localised galvanic corrosion and holes (supposedly used to happen in heat exchangers at power stations after commissioning).  Back re alien microbes, inorganic chemistry is not my bag, but phosphor and sulphur chemistry always seem a complete witches brew to me - lots of viable oxidation states co-existing - the possiblility of an "unknown" or unexpected process seems pretty plausible.

[JamieG]

Study on the impact of climbing chalk on rock dwelling ferns and mosses in Ticino. Hardly surprising but chalk isn't good for the plants. https://onlinelibrary.wiley.com/doi/full/10.1002/ece3.6773

They suggest a potential remedy to the problem in delicate areas

"Furthermore, alternatives to climbing chalk such as adhesive colophony resin or absorptive balls which absorb excess moisture from hands (Niegl, 2009) might be assessed as a potential remedy in cases where the use of climbing chalk is problematic."

But I can't imagine that ever really being implemented (or obeyed). I suspect just banning climbing on certain boulders or areas is a more likely (but not necessarily desirable) solution if plants need conserving.

[teestub]

It seems that maybe gardening and cleaning boulders so that they were climbable may be more detrimental to the florae than the pH imbalance caused by chalk?

[Alex-the-Alex]

Looks like a strong contender for an ignoble award. Though the bit about chalk found in the wider areas interesting I guess. I've wondered about aspects of this before when scrubbing away at some poor lichen. I think the keys figuring out how rare the flora on these boulders is both locally and regionally. I. e are they just on boulders? on every boulder nearby? and is this the only place in the country or world? Also how long do they live? how similar are the communities/individuals on two nearby boulders? I've walked away from plenty of boulders because I've felt it wasn't worth tearing off handfuls of ancient lichen for something 3 people might climb. Its worth some thought as there's more climbers out there and more developing being done and some of it looks more like heavy excavation! Ive, been meaning to write something longer on this and this has spurred me on. 

[Oldmanmatt]

So, saw a couple versions of this article, today. This might not be the best.

It got me wondering about the increasing prevalence of the Medial Artery. It’s not clear from the article that the artery generally exists in addition to the Radial and Ulnar arteries, but that seems the inference.

This must improve forearm endurance/reduce pump, surely? So I’m intrigued to know if the rapid increase in this artery’s prevalence in those born in the late 20th and continuing increase as the 21st progresses, is entirely coincidental to the seemingly massive increase in standards in our little corner of the sporting world?

https://www.independent.co.uk/news/science/wisdom-teeth-evolution-humans-flinders-university-processed-food-b907634.html?utm_content=Echobox&utm_medium=Social&utm_source=Facebook&fbclid=IwAR3pAWdWbobw461SB1jUCB2ypY3rUtV5P6cD1iWpFGHO1jLGsUl0piqSf9I#Echobox=1602262140

[tomtom]

How in earth did you end up down this particular rabbit hole OMM? 😀

[Oldmanmatt]

How in earth did you end up down this particular rabbit hole OMM? 😀

Still waiting for a ship, twiddling my thumbs, and bad weather.
Two weeks already.

It’s like a really long shower.
You start watching a movie and half an hour in, realise you stopped watching and have been pondering world politics/ meaning of life/ price of Kit Kats/ who the hell designed the under wired bra and were they suitably punished?

Seriously though, that’s potentially a 30% increase in blood flow to the forearm, ish, give or take, maybe, if venal return is comparable etc etc.

[Fultonius]

Aye, sulphide corrosion is a right bugger in "dead" pipework.  Interestingly (to me anyway) I think there's an analagous non-microbial process that occurs in "dead" domestic settings, when central heating systems are pressure tested but then left full of static water before use.  You then get pitting corrosion where areas of passivation are stripped but not re-oxidised, resulting in localised galvanic corrosion and holes (supposedly used to happen in heat exchangers at power stations after commissioning).  Back re alien microbes, inorganic chemistry is not my bag, but phosphor and sulphur chemistry always seem a complete witches brew to me - lots of viable oxidation states co-existing - the possiblility of an "unknown" or unexpected process seems pretty plausible.

Microbial action seems to be potentially the main cause of stainless anchors in sea cliffs.

https://cragchemistry.com/2020/10/05/austenite-stability-are-we-missing-something-here/

[Johnny Brown]

I'm not into bolts, but fucking great article that. 

[petejh]

That's a great article! Love the attention to detail.

Doesn't change anything for the UK/Ireland - where 316 is the standard for bolts, even on inland crags, and has been for a long time afaik since the dirtbags experimenting with non-stainless bolts in the 80s/90s. Don't know if I've ever seen a 304 ss bolt in N.Wales?

Euro venues/elsewhere seem to use 304 a lot more, never understood why unless its purely on cost.

''for crags where attack by hydrogen is a possibility, i.e. all crags with high sulphate levels, then any anchor components comprising more than 30% strain-induced martensite look likely to fail some 10 years after installation. On the other hand, anchor components with less than 10% strain-induced martensite will have a service life in excess of 50 years. Put another way, 304 anchors will be short lived, 316 anchors could last many decades.''

[Fultonius]

That said Pete, cheap 316 could still be an issue?  Would be good to see how magnetic the main brands of bolting hardware are. Got any kicking around to check?

I guess in the UK we probably don't have the sulphate reducing bacteria issue, so maybe not an issue?

[petejh]

Yep I have both 316 through bolts and resin bolts here, just need a magnet.. I'll be v.surprised if they're low nickel content but worth a check.

[tomtom]

Most of the places we go climbing in upland UK are shaped by slope processes - such a slides and soil creep. It’s not often that peat slides are caught on camera - and thought I’d share this vid that popped up on my work Twitter feed. I love the trees serenely sailing past!

https://twitter.com/rooneymobile/status/1327581502763380736?s=21

[Will Hunt]

Most of the places we go climbing in upland UK are shaped by slope processes - such a slides and soil creep. It’s not often that peat slides are caught on camera - and thought I’d share this vid that popped up on my work Twitter feed. I love the trees serenely sailing past!

https://twitter.com/rooneymobile/status/1327581502763380736?s=21

The Twitterati seem convinced that it wos the wind farm wot done this.
What causes peat slides? Just waterlogged peat moving under its own weight?

[petejh]

Cool footage! Lucky to see it in the flesh.

Reminds me of this, possibly the craziest landslide footage you’ll ever see..(must have seen this TT?):




Can you imagine being the farmer who started it by digging the foundations, try explaining that to the neighbours and the missus when she got home - ‘I just dig this hole and the whole village disappeared!

[tomtom]

Wind farm? Chinny recon.

Often happen when you have peat formed over a soil with a clay layer. Water gets perched over the clay - friction drops and away you go. Lots of water flowing between the soil/peat debris seen in the foreground.

[tomtom]

Nice link Pete!

[tomtom]

More on the Peatslide here https://blogs.agu.org/landslideblog/2020/11/16/meenbog-peat-slide-1/

Seems the peat sits on bedrock - and the trees planted both add to the weight of the peat and also help water go to the base of the peat quicker (better infiltration) helping the failure at the base of the peat layer (this isn’t in the blog)

[andy_e]

The cause in this case was most probably the wind farm construction, from changing the subsurface water flow and potentially removing some of the weight-bearing load further down the slide. It's happened a few times over the years on Irish peat bogs in relation to wind farm construction and planting of Sitka spruce, neither of which are particularly good for peat bog health.

[Will Hunt]

Good knowledge. I was initially sceptical of the accusations on Twitter as they were made without reference to how the construction might have brought about the slide or even where the slide was in relation to the construction.

[andy_e]

Also worth bearing in mind that Irish peat bogs are far thicker than a lot of what you get on the moorland in England/Scotland/Wales, so more squishy material knocking around to slide all over the place.

[AndyR]

The cause in this case was most probably the wind farm construction, from changing the subsurface water flow and potentially removing some of the weight-bearing load further down the slide. It's happened a few times over the years on Irish peat bogs in relation to wind farm construction and planting of Sitka spruce, neither of which are particularly good for peat bog health.

Indeed - my colleagues and I worked on a couple of ‘bog bursts’ in western Ireland in the early 2000’s that formed as a result of wind farm construction. Typically focussing of near surface flow down into highly humified layers by pad/lay down area/road construction. Bogs are complex things!

[Stu Littlefair]

I really am shockingly ignorant when it comes to biology, but this seems like kind of a big deal...

https://amp.theguardian.com/technology/2020/nov/30/deepmind-ai-cracks-50-year-old-problem-of-biology-research

[jwi]

Yes. Most likely a very big deal. The devil is in the details I am sure, but this looks very promising. Protein folding is one of the most important open problems in computational biology. A pity it is solved by a black box though...