{"id":16744,"date":"2015-11-08T10:49:51","date_gmt":"2015-11-08T10:49:51","guid":{"rendered":"http:\/\/blogs.agu.org\/landslideblog\/?p=16744"},"modified":"2015-11-08T10:49:51","modified_gmt":"2015-11-08T10:49:51","slug":"samarco-1","status":"publish","type":"post","link":"https:\/\/blogs.agu.org\/landslideblog\/2015\/11\/08\/samarco-1\/","title":{"rendered":"Deciphering the Samarco tailings dam disaster in Bento Rodriguez"},"content":{"rendered":"
The Samarco tailings dam disaster in Bento Rodriguez<\/h5>\n

Latest reports<\/a> from Minais Gerais state is Brazil suggest that there are now two known fatalities from the Samarco tailings dam disaster that devastated Bento Rodriguez<\/a>, but that a further 28 people remain missing.\u00a0 News reports suggest<\/a> that about 60 million cubic metres of sludge were released when two tailings dams collapsed. Samarco is now coming in for some criticism for their response to the disaster, and it will be very interesting to see how they handle the inevitable investigation into the dam itself.\u00a0 The fact is that tailings dams should not fail like this – although they do so alarmingly often<\/a>.<\/p>\n

I have seen few images of the location of the source accident itself.\u00a0 The reports consistently suggest that two dams failed.\u00a0 Based on the configuration of the tailings dams, this is most likely to have been the set of dams shown in the Google Earth image below, in which two structures lie upstream of a smaller downstream dam:<\/p>\n

\"Samarco\"<\/a>

Samarco dam configuration via Google Earth<\/p><\/div>\n

.<\/p>\n

So presumably one of the major structures upstream ruptured, triggering a collapse that then over-ran the smaller downstream dam.\u00a0 The best image I have seen that indicates what might have happened in this one (via Estadao<\/a>):<\/p>\n

\"Samarco\"<\/a>

Samarco dam failures via Estadao<\/a><\/p><\/div>\n

 <\/p>\n

.<\/p>\n

This image shows the two upstream tailings dams.\u00a0 The left hand dam (the one to the west in the Google Earth image) above is clearly intact, whilst the one to the west appears to have failed.\u00a0 So, based upon this, the problem seems to lie with this dam:<\/p>\n

\"Samarco<\/a>

Samarco dam via Google Earth<\/p><\/div>\n

.<\/p>\n

It is hard to know what might have happened beyond this, but the surge that came down the valley was enormous, based on the erosion in the valley below.\u00a0 Note the height of the trimline in the vicinity of the second dam.\u00a0 And of course there is now a vast amount of tailings that are not being retained by any structure.\u00a0 Dealing with this debris must be a priority.<\/p>\n

Interestingly there is some information on the internet<\/a> that there has been recent work to increase the height of at least one of the dams.\u00a0 There is nothing to suggest at this stage that these works had any role in the accident, but it will be a factor in the investigation<\/p>\n","protected":false},"excerpt":{"rendered":"

It now appears that about 30 people died in the Samarco talings dam disaster at Bento Rodriguez in Brazil on Thursday. Two tailings dams collapsed, starting with a large upstream structure,<\/p>\n","protected":false},"author":22,"featured_media":16751,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3],"tags":[71,469,122,230],"class_list":["post-16744","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-landslide-report","tag-dam","tag-featured","tag-south-america","tag-tailings"],"_links":{"self":[{"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/posts\/16744","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/users\/22"}],"replies":[{"embeddable":true,"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/comments?post=16744"}],"version-history":[{"count":0,"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/posts\/16744\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/media\/16751"}],"wp:attachment":[{"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/media?parent=16744"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/categories?post=16744"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/tags?post=16744"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}