The Komansu rock avalanche is both very large and quite hard to see.\u00a0 This is a perspective view Google Earth image of the landslide – I’ve annotated the key parts of the slide, based on the interpretation in Robinson et al.<\/em> (2014):<\/p>\n Google Earth perspective image<\/p><\/div>\n .<\/p>\n The current landslide deposit has an estimated volume of 3 – 5 cubic kilometres (although a large part of the deposit has been eroded away), and covers an area of 64 square kilometres – i.e. this is a very large landslide indeed, and we’d expect such a large landslide in very steep, high terrain to have a long run-out. Empirical relationships from similar events suggest about 10 km.\u00a0 However, the Komansu rock avalanche has a run-out that is much longer than this – about 26 km – which asks real questions about the dynamics of the landslide.\u00a0 In other words, what was special about this landslide that allowed it to go so far? An obvious explanation is that the landslide volume was much larger than the modern deposit suggests, but given that the source area only has a volume of about 4 cubic kilometres, this then poses the question as to the origin of the additional material.<\/p>\n Robinson et al.<\/em> (2014) have compared the hummocky topography of the landslide deposit with that of other large landslides from this region.\u00a0 This is a Google Earth perspective view of the deposit:<\/p>\n Google Earth perspective view<\/p><\/div>\n .<\/p>\n Whilst on the face of it the deposit might look a little strange, it is very similar to that found in many other large rock avalanches both in this area and more widely.\u00a0 From this perspective, the landslide is not unusual.\u00a0 The one mechanism that is known to generate usually long runouts is the presence of large amounts of snow and ice – i.e. that is a so-called rock-ice avalanche.\u00a0 However, such landslides tend to have a distinctive final morphology; Robinson et al.<\/em> (2014) suggest that the Komansu rock avalanche deposit does not match this.\u00a0 An alternative, but similar possibility is that the landslide ran-out over a glacier within the valley, but again the morphology does not seem to match that observed from other known examples.<\/p>\n Robinson et al.<\/em> (2014) suggest that the unusual mobility might be explained by the presence of a large amount of ice in the initial failure, and that the landslide then entrained a large volume of material from within the valley.\u00a0 So, the authors propose that the initial failure was about 4 cubic kilometres of rock together with about 500 million cubic metres of ice.\u00a0 This very large landslide then entrained about 4 cubic kilometres of sediment in the valley, plus additional glacial ice, to generate a flow that behaved in a manner that was similar to a volcanic debris flow, allowing the very long runout distance.<\/p>\n A final observation in the paper is that such landslides have substantial implications for hazard assessment in high mountain areas.\u00a0 These giant rock avalanches with long runout distances are clearly extremely destructive.\u00a0 As people increasingly populate the high mountains the likelihood of a mass fatality event, especially during a very large earthquake, increases.<\/p>\n Robinson, T.R., Davies, T.R.H., \u00a0Reznichenko, N.V.<\/span> and <\/span>De Pascale, G.P. (2014). <\/span><\/span>The extremely long-runout Komansu rock avalanche in the Trans Alai range, Pamir Mountains, southern Kyrgyzstan. Landslides<\/em><\/a>, DOI:\u00a010.1007\/s10346-014-0492-y<\/p>\n<\/div>\n","protected":false},"excerpt":{"rendered":" The new paper by Robinson et al. 2014 describes the Komansu rock avalanche in Kyrgyzstan. This is an exceptionally large landslide that traveled about 28 km<\/p>\n","protected":false},"author":22,"featured_media":10211,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[544],"tags":[792,469,337,791,306],"class_list":["post-10210","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-review-of-a-paper","tag-central-asia","tag-featured","tag-kyrgyzstan","tag-review-of-a-plaper","tag-rock-avalanche"],"_links":{"self":[{"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/posts\/10210","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=10210"}],"version-history":[{"count":0,"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/posts\/10210\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/media\/10211"}],"wp:attachment":[{"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/media?parent=10210"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/categories?post=10210"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/tags?post=10210"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}![\"Komansu](\"https:\/\/blogs.agu.org\/landslideblog\/files\/2014\/07\/14_06-Alai-2.jpg\")
<\/a>![\"Komansu](\"https:\/\/blogs.agu.org\/landslideblog\/files\/2014\/07\/14_06-Alai-3.jpg\")
<\/a>Reference<\/h5>\n