12 November 2015
Samarco dam failure
On Youtube there is a video that provides a compilation of videos that are purportedly from the Samarco dam failure that released a mudslide of tailings that destroyed the town of Bento Rodriguez in Brazil a week ago. The video is over 12 minutes long and has clearly been obtained from elsewhere:
The first sequence shows water cascading through the spillway of a dam. I do not believe that this is anything to do with the Samarco dam failure – it does not seem to fit with the observations of the accident.
The second sequence, starting at about 24 seconds, clearly does show an aspect of the disaster. It is not great quality, but my interpretation is that it shows the area of the Fundao dam shortly after its failure. This appears to be be tailings left in the tailing pond:
Whilst this image appears to be site of the dam itself, or what was left of it. There appears to be a great deal of dust in the air – the remains of the movement perhaps?
This actually seems to be the best footage available so far of the site of the Samarco dam, the Fundao dam, that failed, though it does not shed much more light on the disaster.
The next sequence, starting at about 50 seconds, is the most intriguing. This seems to show a very large mudslide arriving in a small rural community in good weather. The slide is enormous and extremely destructive:
I am unsure as to whether this is the event at Bento Rodrigues caused by the Samarco dam failure, but its fits the known facts. It is certainly a most impressive landslide.
Most of the remainder of the video shows the damage from the landslide, which has been described elsewhere.
Meanwhile the fallout continues. As Samarco and its owners struggle to manage the disaster and the publicity, and of course the likely costs, there are suggestions in the media that there had been warnings two years ago that the Samarco dam was not safe:-
A 2013 report conducted by The Instituto Pristino linked to the Federal University of Minas Gerais, warned of structural design flaws and predicted the circumstances that could lead to a dam burst at the Samarco operation.
“The report had already highlighted the fragility of these structures and the necessity of increased rigor in monitoring them,” Brazilian state prosecutor Carlos Eduardo Ferreira Pinto said.
This report is available online in Portuguese as a pdf. The report seems to indicate the potential for the Fundao dam to be destabilised by proposed works for Samarco. It is unclear as to whether the recommendations were taken up or whether the effects noted here played a role in the accident.