Now and then.

It was quite cloudy on the top of Aonach Mor today, so no great pictures today. Through the course of the winter we see significant changes in snow cover. In certain areas the snow builds up to great depths. When standing at the top of, for example, Easy Gully, I often wonder just how much snow there is under my feet. I am still not sure, but thought I would put on some pictures of the top of the East Face taken recently (still quite early in the season), to compare with some taken in the summer to give an indication of snow depth, and how the character of the place changes.

Climbers above central buttress last week.
The top of central buttress is late August. Note firstly that the fence posts are just back from the change in angle, and secondly there are a couple of patches of snow still visible in the background. Last summer (2009) all the snow melted on Aonach Mor during the summer, but a patch did survive over on Aonach Beag. The previous summer 2008, patches of snow survived all summer on both Aonach Mor and Aonach Beag.

The top of Easy Gully yesterday (Sat 30th).

The top of easy gully in summer (during a rare summer ascent of the gully).

Ben Nevis

Some pictures from Ben Nevis today.

With a freezing level of 1800 metres and moderate winds forecast, it's not going to look like this tomorrow I am afraid.

Poor visibility weekend

It was a weekend of low visibility on the tops, so no nice photo's I am afraid. It did clear up today after I had got down from the hill, so here is one of Aonach Mor taken this afternoon. Snow cover is generally pretty good at higher levels, with the ski touring being good if the visibility would clear up. There is also some good climbing on Ben Nevis. With a thaw, followed by a freeze and hopefully some more snow forecast for later in the week, hopefully conditions will improve.

Pictures from today

The cuckoo hut at the top of the ski area was looking quite frosted today.

Climbers at the top of Left Twin. As can been seen the top of many routes are quite corniced at the moment. However, there is often a break in the cornice just beyond where the figure are that can allows an easy way to top out from Left Twin and many of the routes on Central Buttress.

Soft cornices.

Last nights wind and snow has formed some large and fragile cornices. These are prone to collapse both spontaneously, or if disturbed, and can easily release the windslab on the slope below. Unfortunately the light was very flat, and you can't see much in any of the pictures that I took of the cornices. However, the picture shows the side/crown wall of a cornice triggered slab avalanche (notice the rope, I approached this safely via a short abseil from the top). Although this was not a large avalanche in the grand scheme of things (the release area was about 8m across), it would have easily have sent you tumbling should you have been climbing/walking below. Another such crown wall was just visible further along.

If climbing in these conditions it is wise to consider what is above you what is above your route, and avoid gullies with big cornices/areas of windslab above. With a bit of consideration and forward planning (some local knowledge helps as well though) routes which are safe from such objective dangers can almost always be found.

Avalanche on Aonach Mor

On the way up Aonach Mor this morning we heard reports of a "wee slide" being triggered on the West Face at the lowly altitude of about 600 metres. We had been planning to head to that sort of area anyway, so we decided to go and investigate. What we found was a hard slab avalanche had occurred. It was about 50 metres wide, and had run about 200 metres down the hill side. The crown wall reached a maximum depth over a metre, and was 50cm to 1 metre deep from most of it's length. A bit bigger than a "wee slide" I thought. The avalanche had run on a deep and particularly hard layer of small rounded crystals. Today's snow profile is a profile of the crown wall.

Looking south to where the crown wall height was at it's greatest (about 110cm). The first two pictures were taken from the location of the figure in the third picture.

Investigating the crown wall.

Looking back north along the crown wall, it is not too clear but it continues beyond where the figure is. This photo was taken from just below where the figure is in the first picture.

Blowing snow.

Even a seemingly uniform layer of snow will contain many mirco-layers, created by constantly changing conditions as the snow was deposited. Usually these are not too evident, but the strong winds blasting this block of windslab that I dug up really made this micro-layering visible (the horizontal bands).

There was a strong wind on Aonach Mor today. It was very variable in directions, redistributing the existing snow around the mountain. This means that there are pockets of slab on many aspects.

Shearing layers

Three very clean shears came out today when doing a tap test on at the top of the West Face of Aonach Mor. The lollipop sticks were included to mark layers shear, although they are pretty obvious in this case. I am not sure whether you will be able to read scale on the ruler, but in this test these shears occurred at a depth of 12, 20 and 33 cm. This photo was taken on a low angled (about 15 degree) slope with a Westerly aspect. I would be very wary of going onto any steep, snowy slopes with this aspect at the moment.

Looking into Coire an Lochan today. A fair bit of snow on the East Face of Aonach Mor as well.

Deep drifts

Keith looking at one of the big drifts in the summit plateau at Aonach Mor. There are several of these deposits on the summit plateau formed from the wind erosion from the big easterly corries. This one is almost 2 metres deep

More good weather

Another beautiful day in Lochaber!