{"id":17429,"date":"2016-01-15T10:59:11","date_gmt":"2016-01-15T10:59:11","guid":{"rendered":"http:\/\/blogs.agu.org\/landslideblog\/?p=17429"},"modified":"2016-01-15T10:59:11","modified_gmt":"2016-01-15T10:59:11","slug":"wolhusen-1","status":"publish","type":"post","link":"https:\/\/blogs.agu.org\/landslideblog\/2016\/01\/15\/wolhusen-1\/","title":{"rendered":"Wolhusen: an interesting river-blocking rockfall in Switzerland"},"content":{"rendered":"<h5>Wolhusen rockfall<\/h5>\n<p>On Monday a large rockfall occurred on a cliff in the town of <a href=\"https:\/\/en.wikipedia.org\/wiki\/Wolhusen\">Wolhusen<\/a> in Switzerland.\u00a0 The rockfall itself was large &#8211; estimates suggest around 500 cubic metres, with a reported maximum travel distance of 200 metres.\u00a0 Significantly though, the rockfall blocked and diverted the Kleine Emme river.\u00a0 Water flowed through a part of the town, causing extensive damage.<\/p>\n<p>The best set of images that I have found is in this report in the <a href=\"http:\/\/www.luzernerzeitung.ch\/nachrichten\/zentralschweiz\/lu\/luzern\/Entlebucherstrasse-wegen-Erdrutsch-gesperrt%3Bart92,663884\">Luzerner Zeitung<\/a> (the report is in German of course).\u00a0 This aerial image gives the setting rather nicely, showing both the deposit and the diverted river flowing through a part of Wolhusen:<\/p>\n<div id=\"attachment_17431\" style=\"width: 650px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/blogs.agu.org\/landslideblog\/files\/2016\/01\/16_01-Wolhusen-1.jpg\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-17431\" class=\"size-full wp-image-17431\" src=\"https:\/\/blogs.agu.org\/landslideblog\/files\/2016\/01\/16_01-Wolhusen-1.jpg\" alt=\"Wolhusen rockfall \" width=\"640\" height=\"424\" srcset=\"https:\/\/blogs.agu.org\/landslideblog\/files\/2016\/01\/16_01-Wolhusen-1.jpg 640w, https:\/\/blogs.agu.org\/landslideblog\/files\/2016\/01\/16_01-Wolhusen-1-300x199.jpg 300w\" sizes=\"auto, (max-width: 640px) 100vw, 640px\" \/><\/a><p id=\"caption-attachment-17431\" class=\"wp-caption-text\">Drone footage of the Wolhusen rockfall, via <a href=\"http:\/\/www.luzernerzeitung.ch\/nachrichten\/zentralschweiz\/lu\/luzern\/Entlebucherstrasse-wegen-Erdrutsch-gesperrt%3Bart92,663884\">Luzerner Zeitung<\/a><\/p><\/div>\n<p>.<\/p>\n<p>Whilst this image gives a good view of the rockfall itself:<\/p>\n<div id=\"attachment_17434\" style=\"width: 570px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/blogs.agu.org\/landslideblog\/files\/2016\/01\/16_01-Wolhusen-2.jpg\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-17434\" class=\"size-full wp-image-17434\" src=\"https:\/\/blogs.agu.org\/landslideblog\/files\/2016\/01\/16_01-Wolhusen-2.jpg\" alt=\"Wolhusen rockfall\" width=\"560\" height=\"315\" srcset=\"https:\/\/blogs.agu.org\/landslideblog\/files\/2016\/01\/16_01-Wolhusen-2.jpg 560w, https:\/\/blogs.agu.org\/landslideblog\/files\/2016\/01\/16_01-Wolhusen-2-300x169.jpg 300w\" sizes=\"auto, (max-width: 560px) 100vw, 560px\" \/><\/a><p id=\"caption-attachment-17434\" class=\"wp-caption-text\">Wolhusen rockfall via <a href=\"http:\/\/www.luzernerzeitung.ch\/nachrichten\/zentralschweiz\/lu\/luzern\/Entlebucherstrasse-wegen-Erdrutsch-gesperrt%3Bart92,663884\">Luzerner Zeitung<\/a><\/p><\/div>\n<p>.<\/p>\n<p>It does appear that the rockfall itself was unusually energetic.\u00a0 The <a href=\"http:\/\/www.luzernerzeitung.ch\/nachrichten\/zentralschweiz\/lu\/luzern\/Entlebucherstrasse-wegen-Erdrutsch-gesperrt%3Bart92,663884\">Luzerner Zeitung report<\/a> also includes this image of damage to one of the adjacent building, appearing to show impact marks from debris extending to a high level.\u00a0 It is fortunate that no-one was in the way of one of these pieces of rock.\u00a0 This can be explained by the timing of the rockfall, which was at night:<\/p>\n<div id=\"attachment_17435\" style=\"width: 543px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/blogs.agu.org\/landslideblog\/files\/2016\/01\/16_01-Wolhusen-3.jpg\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-17435\" class=\"size-full wp-image-17435\" src=\"https:\/\/blogs.agu.org\/landslideblog\/files\/2016\/01\/16_01-Wolhusen-3.jpg\" alt=\"Wolhusen rockfall\" width=\"533\" height=\"400\" srcset=\"https:\/\/blogs.agu.org\/landslideblog\/files\/2016\/01\/16_01-Wolhusen-3.jpg 533w, https:\/\/blogs.agu.org\/landslideblog\/files\/2016\/01\/16_01-Wolhusen-3-300x225.jpg 300w\" sizes=\"auto, (max-width: 533px) 100vw, 533px\" \/><\/a><p id=\"caption-attachment-17435\" class=\"wp-caption-text\">Rockfall impact marks on an adjacent building, via <a href=\"http:\/\/www.luzernerzeitung.ch\/nachrichten\/zentralschweiz\/lu\/luzern\/Entlebucherstrasse-wegen-Erdrutsch-gesperrt%3Bart92,663884\">Luzerner Zeitung<\/a><\/p><\/div>\n<p>.<\/p>\n<p>The <a href=\"http:\/\/www.luzernerzeitung.ch\/nachrichten\/zentralschweiz\/lu\/luzern\/Entlebucherstrasse-wegen-Erdrutsch-gesperrt%3Bart92,663884\">report suggests<\/a> that the damage will cost over a million Swiss Francs (which is about US$1 million).\u00a0 Note from the first image that the landslide occurred on the outside of a gentle curve of the river, which would suggest that the key mechanism here might have been undercutting of the rock face.\u00a0 In the second image the unweathered surface shows the origin of the landslide &#8211; it appears that there is at least some recent fracturing here to allow the final detachment to occur. I am unclear as to whether there was a distinct triggering event.<\/p>\n<!-- AddThis Advanced Settings generic via filter on the_content --><!-- AddThis Share Buttons generic via filter on the_content -->","protected":false},"excerpt":{"rendered":"<p>On Monday night a large rockfall in Wolhusen blocked the Keine Emme river, causing a flood through a local industrial park. Estimated damage is US$1 million<!-- AddThis Advanced Settings generic via filter on wp_trim_excerpt --><!-- AddThis Share Buttons generic via filter on wp_trim_excerpt --><\/p>\n","protected":false},"author":22,"featured_media":17431,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3],"tags":[144,469,59,959,485,56,444],"class_list":["post-17429","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-landslide-report","tag-europe","tag-featured","tag-flood","tag-landslide-report","tag-river","tag-rockfall","tag-switzerland"],"_links":{"self":[{"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/posts\/17429","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=17429"}],"version-history":[{"count":0,"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/posts\/17429\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/media\/17431"}],"wp:attachment":[{"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/media?parent=17429"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/categories?post=17429"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/tags?post=17429"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}