Cleft Peak Rock Fall

Fantastic to see such images - very well done on capturing such an event - great quality images too! As a geomorphologist this interests me enormously. I am writing a chapter for a book on the Drakensberg and would love to include one or more images if acceptable. It would also be great to see images of the rockfall scar after the event - should you have any such pictures. By the way, we have a GIS mapping programme on rockfalls for the Golden Gate area. We also had a PhD project on landslides and rock fall completed earlier this year for the Bushman's nek region. Despite all our work, I have never seen such an event in action.....I have heard small rock falls and they are loud indeed, so can only imagine this must have been thundrous!

I would appreciate some images. My e-mail address is: This email address is being protected from spambots. You need JavaScript enabled to view it.

Stefan Grab

Thanks for sharing

Quite scary I think! Must have sounded amazing.

It made my day to see these photos.

Like Stefan, I'm interested to see the scar left behind so that we can work out where the event started. I would imagine that all the large orange bits of the escarpment are evidence of these kind of events.

What time of day did it happen? I would guess that the winter freeze-thaw process of ice might have been behind the rockfall (ice expands, so where the altitude allows freeze and thaw on a daily basis in winter, there is lots of pushing and shoving without anything getting tired).

There's an age-old debate about whether fast processes like this one do the most amount of work in erosion/denudation, or whether it is slow, imperceptible agents over long time spans that is responsible.

On the latter, I have a photo from the early 1990s of some mates of mine doing handstands underneath that rock in Rainbow Gorge - the one that is jammed in the sides of the gorge. They have to bend their legs to fit between the stream bed and the bottom of the rock. Last time I was there, the rock was almost out of reach. The stream had eroded down 1/2 a meter or more.

So there seems to be a far bit of interest in this fall. There is in fact quite a bit more info I can share. I do have before and after pics. I think we can probably pin point the block which fell. As far as the scaring its very evident.

The most interesting part for me was actually the following timeline:

1)Hiking up organs pipe pass a clear rockfall is heard, may have been on Cleft? Close by? (Friday)(My first rockfall heard)
2) While sitting in Rolands cave a rock fall again is clearly heard, but fainter. (Friday Night, extremely windy)
3) Hiking back to Cathedral peak hotel, Yolandi is deep in conversation, I interupt and say "did you hear that" all say no. Yolandi talks again and I hear the same sound and say "Sush" we look around and then see the rock fall starting. (Monday Moring, 11:00)
4)My camera is in the side pocket of my bag which I grab and snap the photos you have seen. (Note this takes time, back was about 3m away, camera had to start up etc. Which gives you an idea of the height of the fall.)
5) The dust cload interestingly did not settle but lifted.

Considering the position we where at, and the speed of sound, I think it is fair to say that the sounds prior to the fall must have been rock breaking, but not failing catastrophically. This allowed us time to see the entire event, even though the sound only reached us later.

As for the fall heard on Friday, does anyone have any recent pictures of Cleft? We may be able to pin point a fall that happened on the friday. (Or could this have been cracking, I think not as it sounded like a fall rather than a gunshot.)

Lastley the size of the blocks falling were massive. Hard to describe, but to be able to see them with a naked eye from that distance they had to be very large. 50m size maybe? They actually broke off as a single unit.

Others with us will be able to give a better acound as I was busy with the camera.

With regards to the scaring and the actual path of the fall, size rocks at the bottom. Its all there, nice and fresh right now. So if you guys are that keen put a pack on and do some proper investigation. I wouldnt be suprised if more has come off since. We didnt walk back that way.

Maybe those interested should catch up for a beer and chat through the fall. Maybe learn something?

@ Frosty Ice: I have quite a few pics of Cleft Peak from about two months ago, will upload them to this topic tonight.

Eish, this time of the year the thought of rock fall is constantly in one's mind, big or small (single rocks etc). Last week when climbing Mafatle peak in Goldengate, some of the steep side hilling grassy traverses became a toss-up between walking precariously close to an edge versus walking right underneath rockwalls with clear evidence of wall erosion around. I chose the middle ground where possible...

Speaking of the park, also with reference to Stefan's post, herewith a pic of the most well-known rockfall in the park. Clearly visible from the roadpass, this photo taken from atop Little Caledon peak. Scarring is clearly visible, i.e. the bit that came off looks a bit fresher than the surrounding dolomite rockfaces.



A further chilling thought just entered my mind. Tuesday afternoon I was standing atop that prominent lip of the Mushroom rock above Glen Reenen. hmmmm, may have been looking for trouble.

This weekend we went up Gray's pass and me and the laaitie nearly got taken out by some falling rocks. One the size of a soccer ball landed about 2 meters from us. All of this thanks to the baboons running around on top of the cliff face. Lesson learnt.

Frosty ice- thanks for the detailed description. Wish I had time to go to the site soon...but will have to waite a while. Acoustic emissions are know with the freeze-thaw process. Possible it was related to freeze-thaw and/or thermal stress. THose rock walls freeze to many degrees below 0°C at night and rapidly warm in the morning as they are east-facing. Do you have more pics from after the event?
Stefan

I was thinking about this event yesterday when visiting the Cathedral peak area, keen to see whether scarring would be visible on Cleft peak after the recent rock fall.

I did not check this thread before leaving so only developed my theory this morning after checking some photos I took yesterday.

Looking at the original photo as posted by Frosty Ice, it is clear on which vertical line the rockfall occurred. Some scarring on the rock face can also be seen about halfway down the vertical section of the cliff. See photo below.



A close up gives, in my opinion, a clue as to where the rockfall originated. It is most likely the bottom left part of the overhang that came loose and tumbled down. See close up below with my guess.

Yes, HF you are 100% correct. The scaring was previously more pronounced.

The bock did indeed sit where you suggest. The size of the block which fell was massive, bit interesting to work out how big it was.

I still owe a few photo's to some people, will do that this week.