1 June 2010
The latest photos from the site, taken late yesterday, show that the retrogressive erosion of the channel is continuing to develop rapidly. This image was taken at about 5 pm yesterday:
The lower part of the channel has widened and, more importantly, the steep section has moved up channel considerably. Bear in mind that this image is more than 15 hours old now. The best illustration of the way that this is developing is with this sequence of three images, which are taken about a day apart, starting on 29th May on the left and ending with 31st May on the right:
It seems to me that release of the water in the lake is now highly likely in the next few days. The most likely mode of failure looks to be this retrogressive erosion, which could lead to a rapid release event, but the initiation of erosion through downcutting cannot be ruled out. Downstream communities need to be prepared.
I have received no update on the state of flow in the channel – I will post again when some information becomes available.