11 August 2009

A strange update on the Nachterstedt landslide

Posted by Dave Petley

A strange update has appeared in the “The Local” regarding the Nachterstedt landslide. This reports that “Scientists at the Collm Observatory at Leipzig University registered an underground movement in the area measuring 1.0 on the Richter Scale, just six minutes before the first call to the emergency services on July 18. An earthquake can be ruled out, the scientists told Der Spiegel magazine, but they suggested it would be feasible that an old mining tunnel collapsed, causing the landslide. “

For info a magnitude 1.0 earthquake is the equivalent of about 30 kg of TNT. I cannot understand why the scientists believe that this was a tunnel collapsing. To me it is far more likely that the signal was the landslide itself occurring. I must admit that I cannot understand why the collapse of an underground mine working would cause this catastrophic slide anyway.

On another matter, the paper also reports that a further collapse is considered likely:
“Surveyors have been pulled back out of the Auf der Halde community, where the ground has sunk by a further 0.4 millimetres and is expected to also collapse. Preparations are now being made for emergency measures to be taken should the remaining houses also fall into the Concordia Lake, which was created by flooding an old open-pit mine.”