‘Peculiar’ of Odious and Peculiar reports that a tectonic fissure opened up in Ethiopia last September that is 37 miles long and 13 feet wide. Neither Peculiar nor his/her source tells us what I most want to know: how deep is it? Surely scientists have tried dangling instruments on ropes, or just dropping them in. A simple microphone or even a cellphone would give some clues: just listen to figure out how long it takes to stop falling and/or bouncing. I suppose reception would be a problem after the first few hundred feet. So why not a rock on a rope?

The picture provided was also a bit puzzling at first, since the cleft is a lot wider than 13 feet at the top. Of course, that is because the rift is deep enough that the original sharp edges fell in and were swallowed up. The area looks quite sandy. Here’s a diagram of what must have happened. Original rift (probably only existing for a second or two):

Rift after the edges fell in:

Roughly how far the debris fell is what I really want to know.

Further desultory thoughts:

I’m impressed by how close to the (new) edge the scientists are standing.

In such a sparsely-populated area, I don’t suppose anyone fell in when the rift opened up – not that it would be at all easy to tell unless someone else saw it happen. But a 37-mile bottomless canyon can’t be good for those unfortunate enough to have family or friends on the far side.