A quick update from the Marble Steps dig:
We’ve continued digging downwards in the choked shaft, following the draft, and occasionally the sound of water. We had two solid walls to work between, which made the shoring a good bit easier than it had been previously.
After a few trips we reached the water level in a flooded rift, which is highly likely to be at Keld Head/ Marble Steps static sump level, although we haven’t surveyed it yet to confirm this. We’ve plumbed the flooded rift to at least 3m deep, but it could well be much deeper.
At the far end of the flooded rift, there’s a small airspace which the draft blows through. Unfortunately the airspace probably isn’t useable because of a flake which drops below the water level. Trying to push it as a duck would be pretty spicy in deep water! In wet weather we’ve heard running/ falling water ahead, so it’s pretty likely that an inlet enters beyond, hopefully with an enlargement. We could fairly easily enlarge this rift, but we don’t want to block the way on underwater.
Unfortunately the unsettled weather has slowed down progress, but the next stage will be for someone to dive the flooded rift (it’s too early to call it a sump yet!). The development seems to be trending towards Keld Head and away from the choke, so there’s reasons to be hopeful that the way on will be open underwater. The static sump is about 100m away from our new flooded rift, and initially goes in the opposite direction, so it seems unlikely that there’s a direct connection between the two underwater. Our new pool almost certainly takes the flow from the main chamber in flood, and it’ll be interesting to see what happens now that we’ve opened up the choke enough to allow a considerable amount of water to flow through!
