21 May 2010

Seepage at the Attabad landslide

Posted by Dave Petley

Focus have today kindly provided a new set of measurements of the state of the Attabad landslide.  I will update the monitoring site shortly, but in the meantime here is the graph of the development of seepage.  The plot of seepage against time suggests that the trend in the rate of development of seepage changed on the last few days.  Note how the most recent point does not fit on the curve that one would extrapolate from the previous days data::

However, when the same data are plotted against lake depth this discontinuity in the trend disappears:

This might suggest that the seepage is being drive primarily by the water depth, and that the little disconnect in the current trend suggests that seepage is likely to increase substantially in the final stages before over-topping.  This is probably supported by the suggestion that sinkholes are opening up on the dam by the Pamir Times yesterday, although the image that they provided to illustrate this does not really seem to show sinkholes: