UKC

Yesterday a huge buttress in the  The Lost World/Heaven Walls collapsed.

The routes North West Face of the Druid (E6 6a) and the The Coolidge Effect (E4) are basically totally distroyed as everything above the tunnels has fallen down.

It has left a rather fine wall with a good looking crack though.

It was hard to tell but it appears the two tunnels running to Mordor are still clear.

Saw/heard the aftermath of this from afar. Was an impressive dust cloud to say the least!

We were climbing the Dinorwic Unconquerable at the time. It was impressive up close as well.

The wall had been dropping small rocks for an hour prior to it going and in the proceeding five minutes there was the sound of continual rock fall. It was all taking place in the chimney forming behind the buttress with clouds of dust appearing from the tunnel mouth and on the third pitch of the Coolidge Effect.

It gave loads of warnings. If you are in one of those holes and loads of small stuff comes down without an obvious culprit knocking it off I'd leave sharpish. 

Any photos?

I think this link will work.......

https://www.flickr.com/photos/159287761@N07/?

and before....

https://www.aditnow.co.uk/SuperSize/Lost-World-Collapse-2014_95182/

Wow, cheers for the photos, to think I and many others have fairly recently stood inside that tunnel entrance that's now completely gone from the face of the cliff on several occasions!

So that's the third big rockfall in Lost World in as many years!

This is very sad. The Lost world was amazing I spent a few happy weekends in the bothy down there.

The section highlighted is what fell. The sight of it slowly tilting forwards was amazing. I'm glad we were as high on the other side as we were. If we had been on the level below I think it would have been scary!

I did not drop back down to have a look but from where I was it appeared that the tunnels through to Mordor were still clear.

The remaining wall or slab left behind appears to be very impressive. I'd have thought that an abseil approach might yield something of interest as it would avoid all the rubble strewn lower ledges.

The "proper" version of snakes and ladders has been destroyed for ages now anyway

The tunnel through from Lost Worlds to Mordor is fine. much was has been said has fallen down.

Give us a shout if you need a belay on any new routes Mark!

Thanks. It looks like there were some big rockfalls even before 2009, it must slowly have been going. Looks like the falls are getting bigger though.

That's pretty scary! I tended to assume things only fell down in winter during bad weather (storms, freeze-thaw etc.). It's pretty unnerving to think that any piece of rock could collapse even in benign conditions.

I'd imagine from a position of no real geological knowledge that it was connected to the hot weather.

Yosemite experiences high rockfall during periods of hot weather. The solar gain on the slate was large. It was hot to touch anywhere it was in direct sunlight.

https://www.usgs.gov/news/hot-days-can-trigger-yosemite-rockfalls 

Agreed. Anything that causes expansion or contraction is going to make things fall down. Once mobile debris starts filling a chimney it's only ever going to get wider as the debris slowly falls further into it with a wedging effect.

Maybe we should be watching Castle Rock in the hot weather

Someone was watching it very closely when we drove past on Friday - they were half way up Overhanging Bastion. Rather them than me!

Interesting, thanks.

Slightly alarming to read in that article that the crack grew by up to half an inch. That'd be enough to make your nuts pop out if you were hanging around for too long.

I think we underestimate the impact of temperature on cliffs.

I climbed Central Wall (E3 6a) one new year. It was a clear cold day and the waterfall at the base of the crag was frozen solid.

All of the belay pegs could be removed by hand! I left them all where they were and belayed on other gear. I returned the following summer and reclimbed the route. All of the pegs were solid.

I doubt that anyone had climbed that route with a hammer and reset them. Who carries a hammer. I think it was just a result of temperature changes.

Agree. It is very dry weather that will encourage rock fall in the lakes, largely due to soil shrinkage and related things.