{"id":4216,"date":"2012-02-01T09:57:30","date_gmt":"2012-02-01T09:57:30","guid":{"rendered":"http:\/\/blogs.agu.org\/landslideblog\/?p=4216"},"modified":"2012-02-01T09:57:57","modified_gmt":"2012-02-01T09:57:57","slug":"investigating-the-tumbui-quarry-landslide-in-papua-new-guinea","status":"publish","type":"post","link":"https:\/\/blogs.agu.org\/landslideblog\/2012\/02\/01\/investigating-the-tumbui-quarry-landslide-in-papua-new-guinea\/","title":{"rendered":"Investigating the Tumbi Quarry landslide in Papua New Guinea"},"content":{"rendered":"

Despite widespread calls<\/a> for an investigation of the Tumbi Quarry<\/a> landslide<\/a> in Papua New Guinea, and a pledge from the PNG Government to undertake such an inquiry, there is little evidence of action<\/a>.\u00a0 Given the suggestions, at the moment with no hard evidence either way in the public domain, that quarrying operations for the Exxon-Mobil LNG pipeline project may have played a part in the initiation of the landslide, this is somewhat unfortunate.\u00a0 RNZI<\/a> has today posted an article from which this quote is taken:<\/p>\n

“Christine Yango denies that the project is to blame for the landslide, saying it was a natural phenomenon which has nothing to do with nearby LNG activity”<\/p><\/blockquote>\n

Christine Yango is the Liaison Officer with Oil Search, one of the partners in the LNG Project.\u00a0 If this quote is true then it appears that the company has already come to a conclusion about the landslide.\u00a0 I wonder as to the basis for this.<\/p>\n

So lets just summarise what we know about the landslide.\u00a0 First, the landslide is located at, and indeed has destroyed, the Tumbi Quarry site.\u00a0 This is clearly evident from the first image that I posted:<\/p>\n

\"\"<\/a><\/p>\n

The remains of what I infer to be the quarry roads and cuts are located in the upper right part of the image, although most of the works appear to have been destroyed.\u00a0 It is interesting to note that there is no real sign of the spoil (e.g. topsoil) from the quarry works – I wonder where the dump sites for this were located (this is peculiar given the indicative locations in tha map below)?\u00a0 If downslope or upslope of the main quarry area then this may have been a factor in the development of instability.<\/p>\n

Second, the LNG project documentation<\/a> clearly states that a quarry at this site was to be used in the LNG Project for aggregate extraction.\u00a0 On page 6 it states that “Tumbi Quarry, known as QA1, is required for aggregate to be used by the Project in the Komo area”.\u00a0 The document even provides a map of the proposed quarry (see page 10 of the pdf):<\/p>\n

\"\"<\/a><\/p>\n

To gain an understanding of the orientation, the photograph above has been taken from the northeast looking southwest onto the site.<\/p>\n

This indicates that the quarry site was located right in the middle of the section of slope that has failed.\u00a0 It is bold to suggest that the two are not linked without undertaking a proper investigation.<\/p>\n

Finally, if this is a natural slope failure, I wonder what was the cause?\u00a0 The images do not suggest that heavy rainfall was occurring at the time, and I have seen no indications of earthquake activity.\u00a0 It is true that progressive failure sometimes means that a slope fails without a trigger, but if so then the site would have shown\u00a0 extensive evidence of deformation – e.g. cracks, grabens, lateral scarps, etc.\u00a0 If the ground showed such features then these would normally be picked up in the ground investigation prior to the extension of the quarry, and during routine monitoring as the quarry was developed.\u00a0 If such features were present, the quarry is unlikely to have been developed – the risk of failure would have been too high. And if they were picked up in routine monitoring, action would have been taken immediately as slope failures are a major threat to quarry operations.<\/p>\n

So there is a real contradiction here that needs addressing:<\/p>\n