15 June 2016

The boulder that came to tea

Posted by dr-dave

The boulder that came to tea

The Croatian news website Dulist has a story this week about a boulder that came to tea in a house in Dubrovnik.  The pictures are quite startling:-

boulder that came to tea

The boulder that came to tea – via Dulist

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According to a translation of the article, this landslide happened during heavy rainfall on Monday night.  This block was part of a larger landslide on State Road D-8.  The images suggest that this boulder bounced on the road before smashing through the broadside barrier:

The boulder that cam to tea, via Dulist

The boulder that came to tea – the roadside impact, via Dulist

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And then bounced again in the garden of the house (note the huge divot in the grass), before trying to gain entry via the a bedroom window:-

The boulder that came to tea

The boulder that came to tea, via Dulist

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This looks to be a classic case of a boulder that is rotating around its shortest axis, and so has gained a stable geometry as it travels down the hill.  This situation creates the possibility of high velocities, large bounces and long travel distances.

I’d imagine that removing the boulder from the window is not going to be a trivial task

According to the Dulist article, the same house was struck by a boulder in 2012.  The Google Translation of the article, which I have tidied up, says:

The Křečková house has already been hit by a big boulder, almost exactly four years ago, namely on 16 June 2012, when the rocks in the fall broke several trees, skipped the road, bounced off the railing of the road, glanced off the fence sound the driveway parking and travelled like a projectile through the roof of the house. Fortunately the roof structure was able to stop the rock.

All of this suggests that some work is needed quite urgently to assess the stability of the slope above the road.  The article appears to suggest that there may be more unstable blocks.