Discussion: mapping a boulder as a cliff

should this boulder be mapped as a boulder or cliff ?

http://picasaweb.google.com/100506671808305662069/...

Cliff, or not at all, depending.

Judging by the surrounding terrain, it is a mappable feature and I would map it as a cliff.

cliff

cliff.

That's not a boulder.

It's neither a cliff nor a boulder... it's a "203.0/1 Passable rock face" in OCAD-speak.

Actually in my part of the world it's called a small crag.

In my part of the world that's called pedantic!

Pedantic or not, my new-to-orienteering daughter nearly refused to punch at such a control on her novice map which included 'cliff' in the textual description. In non-orienteering speak, this is not a cliff.

boulder. I'm guessing a giant would be able to detach that and roll it down the slope (which is my criteria).

Okay, passable rock face, that other cliff.

Assuming the lower photo is looking downhill from above, and guessing on slope and scale, to me this looks like a very typical boulder, 0.2/ 0.8m (?), on a steep slope, in relatively rock-free terrain. Most boulders in this context will inevitably function like mini cliffs with a high and low side, so that isn't an issue.

To map it as a cliff, to ISOM or ISSOM min size would greatly exaggerate the size, and significance of the feature, simply too much black ink (toner) on the map for the size of the object.

Granted, some exaggeration is OK, but a clff should also be predominantly linear, which I don't perceive here.

Different answer in other settings.

Mapping it as a cliff will tell the runner that it is primarily visible from downhill, that it has a vertical surface, and that it is made of rock.

If you map it as a boulder and someone passes it on the uphill side they may think to themselves, "0.2m high boulder? Nice mapping."

That's no moon boulder, that's a space station passable rock face.

Huh. Doesn't flow as well, somehow.

It is a little hard to tell how big the thing is from the photo. If I ran by it in the middle of a leg, I don't think I'd expect it to be mapped. I certainly wouldn't be disturbed if it weren't mapped.

>Mapping it as a cliff will tell the runner that it is primarily visible from downhill...

The boulder symbol, in the assumed settting of smaller-than-average mappable rock features on a steep slope, already presumes/describes/implies this one sided situation. There's no need to use a symbol with even greater visual impact on the map, to make this point.

If the local standard for mapping rock features is average or higher, or the slope is less steep than I perceive, then this already small object should become a "nothing", certaily not a stronger feature.

If my sense of scale is so misguided that this object is more like 0.5/ 2.0m, then I would probably agree to a min. size, rounded or angled (not straight line) tagless cliff, in a small rock feature context.

If not mapping this object is an option, I would probably agree to this in an average setting, assuming 0.2/ 0.8m dimensions.

Dot knoll with some grey bare rock on the other side of the knoll, and two from lines on both sides, going straight to indicate there is no any other land forms than just the dot knoll. And one slope line for each form line. Terrain becomes more technical and everybody will enjoy it.

I'd map it as ISOM 203, passable rock face, without the tags, and with the minimum length of 0.6mm. Preferably draw this on or very close to a contour line - it might mean moving the contour line to accommodate this. I don't think a form-line is warranted.

Instead of mapping it, move some more leaves on top of it and it won't be visible at all.

Or if the map has a serious lack of details you can remove some leaves and map it as a boulder.

and where is this bouldercliffcragdotknollpassablerockface? it looks like a nice forest.
Dot Knoll? gimme a break...

I'd try and leave it off the map (throw a couple of branches over it to hid it if you feel you must).

If it must go on the map then it is a very small passable rock face.

Jagge said:
"Dot knoll with some grey bare rock on the other side of the knoll, and two from lines on both sides, going straight to indicate there is no any other land forms than just the dot knoll. And one slope line for each form line. Terrain becomes more technical and everybody will enjoy it."

I disagree, I don't think you need the dot knoll, just think a single form line indicating a spur, with possibly a second form line showing a small knoll on the spur, and, of course the bare rock symbol too. :-).

I don't think Jagge was being entirely serious...

You could map it as pink boulder, cliff or rock face and hide the symbol layer from map prints - too small to be mapped. If you one day are in serious need for a control feature, you can peek what you have in your hidden "too small objects" layers and pick one and convert it to normal object to be used for a control site for this one training/event/whatever only. Add control stand, control flag and kick some leaves off, it all together will make it prominent enough to be mapped.

Those Finns! No wonder I never do well at the Fin5. Despite being married to one, I've never been able to entirely understand most Finns' sense of humor...

I've had controls on much smaller features, it depends on the area to be honest. Looking at the fallen tree it's almost 1m high at the largest part.... But if it's going to go on the map then it's got to be a small crag. If you are coming from the top there is basically nothing there. It doesn't matter if it's a boulder which has been buried on one side, if has a face from only the downhill aspect, therefore it's a crag.

Agree with Nixon, my guess was that it is 1m -1.5m high based on the fallen tree. If less than 1m, probably wouldn't map it. If the rest of the map which you can't see in the photos has thousands of 2m-5m boulders and cliffs then maybe it is as insignificant as Jagge implies and you wouldn't map it. But I'm guessing that there aren't many other features in this area, in which case it becomes quite significant. One thing that worries me is do you hold events there in summer when the deciduous trees could mean that the whole area is green - in that case I wouldn't want to use it as a control site.

I endorse Jagge's excellent recommendations, though I am a little surprised he did not mention mapping the other prominent boulders visible in picture two, nor the salient dueling rootstocks in evidence there. And with two rootstocks so close by, you can almost infer the presence of a third rootstock, even though it doesn't seem to appear in the photo--probably just poor photo quality.

Plus, you never know when you might need distinctly different features close by so you can hang many flags in the same control circle. Probably the area should also be thoroughly examined for surface dimples which could serve as pits or small "u" depressions, which are always useful.