{"id":19334,"date":"2016-07-28T06:56:49","date_gmt":"2016-07-28T06:56:49","guid":{"rendered":"http:\/\/blogs.agu.org\/landslideblog\/?p=19334"},"modified":"2016-07-28T06:56:49","modified_gmt":"2016-07-28T06:56:49","slug":"illgraben-debris-flow-video","status":"publish","type":"post","link":"https:\/\/blogs.agu.org\/landslideblog\/2016\/07\/28\/illgraben-debris-flow-video\/","title":{"rendered":"Illgraben debris flow video"},"content":{"rendered":"<h5>Illgraben debris flow video<\/h5>\n<p>The Illgraben is a very active alpine catchment located near to the near the village of Susten (Leuk), in Canton Valais, Switzerland.\u00a0 This catchment is particularly interesting because it generates a large number of debris flows, some of which are very large.\u00a0 Since 2000 <a href=\"http:\/\/www.wsl.ch\/fe\/gebirgshydrologie\/illgraben\/index_EN\">WSL has been using Illgraben as a monitoring site for debris flows<\/a>.\u00a0 They have installed instrumentation in the catchment and in the debris flow channel.\u00a0 Not surprisingly, cameras are a part of the set-up, meaning that several large debris flows have been recorded.\u00a0 WSL has also built a warning system for the catchment in order to protect the local population.<\/p>\n<p>Pierre Zufferey has recently posted a video of one such debris flow on <a href=\"https:\/\/www.youtube.com\/watch?v=0ENe7wDKP6I\">Youtube<\/a>.\u00a0 This event occurred on 22nd July 2016 according to the Youtube page.\u00a0 It is truly spectacular:<\/p>\n<p><iframe loading=\"lazy\" src=\"https:\/\/www.youtube.com\/embed\/0ENe7wDKP6I?rel=0\" width=\"640\" height=\"360\" frameborder=\"0\" allowfullscreen=\"allowfullscreen\"><\/iframe><\/p>\n<p>.<\/p>\n<p>In one film this video illustrates many of the characteristic elements of a debris flow.\u00a0 So, for example, the front of the flow consists of large number of (in this case) huge boulders tumbling chaotically:<\/p>\n<div id=\"attachment_19335\" style=\"width: 555px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-19335\" class=\"size-full wp-image-19335\" src=\"https:\/\/blogs.agu.org\/landslideblog\/files\/2016\/07\/16_07-Illgraben-1-e1469687554237.jpg\" alt=\"Illgraben\" width=\"545\" height=\"421\" srcset=\"https:\/\/blogs.agu.org\/landslideblog\/files\/2016\/07\/16_07-Illgraben-1-e1469687554237.jpg 545w, https:\/\/blogs.agu.org\/landslideblog\/files\/2016\/07\/16_07-Illgraben-1-e1469687554237-300x232.jpg 300w\" sizes=\"auto, (max-width: 545px) 100vw, 545px\" \/><p id=\"caption-attachment-19335\" class=\"wp-caption-text\">The boulder-dominated front of the Illgraben debris flow, via <a href=\"https:\/\/www.youtube.com\/watch?v=0ENe7wDKP6I\">Youtube<\/a><\/p><\/div>\n<p>.<\/p>\n<p>Behind the front the debris flow consists of a very debris rich but much more fluid slurry:<\/p>\n<div id=\"attachment_19336\" style=\"width: 650px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-19336\" class=\"size-full wp-image-19336\" src=\"https:\/\/blogs.agu.org\/landslideblog\/files\/2016\/07\/16_07-Illgraben-2-e1469687709355.jpg\" alt=\"Illgraben\" width=\"640\" height=\"432\" \/><p id=\"caption-attachment-19336\" class=\"wp-caption-text\">The main, more fluid portion of the Illgraben debris flow, via <a href=\"https:\/\/www.youtube.com\/watch?v=0ENe7wDKP6I\">Youtube<\/a><\/p><\/div>\n<p>.<\/p>\n<p>As the discharge starts to decline the debris flow creates a narrower channel, leaving deposits (levees) on both flanks:<\/p>\n<div id=\"attachment_19340\" style=\"width: 650px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-19340\" class=\"size-full wp-image-19340\" src=\"https:\/\/blogs.agu.org\/landslideblog\/files\/2016\/07\/16_07-Illgraben-3-e1469687956133.jpg\" alt=\"Illgraben\" width=\"640\" height=\"407\" \/><p id=\"caption-attachment-19340\" class=\"wp-caption-text\">Declining flow in the Illgraben debris flow, via <a href=\"https:\/\/www.youtube.com\/watch?v=0ENe7wDKP6I\">Youtube<\/a><\/p><\/div>\n<p>.<\/p>\n<p>By the end of the video the flow has migrated into the centre of the channel, leaving new debris flow deposits on either bank, and creating a morphology very similar to that before the flow arrived (see the first picture above):<\/p>\n<div id=\"attachment_19342\" style=\"width: 638px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-19342\" class=\"size-full wp-image-19342\" src=\"https:\/\/blogs.agu.org\/landslideblog\/files\/2016\/07\/16_07-Illgraben-4.jpg\" alt=\"Illgraben\" width=\"628\" height=\"434\" srcset=\"https:\/\/blogs.agu.org\/landslideblog\/files\/2016\/07\/16_07-Illgraben-4.jpg 628w, https:\/\/blogs.agu.org\/landslideblog\/files\/2016\/07\/16_07-Illgraben-4-300x207.jpg 300w\" sizes=\"auto, (max-width: 628px) 100vw, 628px\" \/><p id=\"caption-attachment-19342\" class=\"wp-caption-text\">The final phase of the Illgraben debris flow, via <a href=\"https:\/\/www.youtube.com\/watch?v=0ENe7wDKP6I\">Youtube<\/a><\/p><\/div>\n<p>.<\/p>\n<p>WSL will have captured this debris flow in their instrumentation.\u00a0 I would imagine that it will be a fascinating dataset.<\/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>A fantastic video has been posted on Youtube showing a very large debris flow in the Illgraben catchment in Canton Vallais, Switzerland.<!-- 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":19335,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[29],"tags":[57,1156,144,469,963,39,444],"class_list":["post-19334","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-landslide-video","tag-debris-flow","tag-early-warning","tag-europe","tag-featured","tag-landslide-video","tag-monitoring","tag-switzerland"],"_links":{"self":[{"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/posts\/19334","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=19334"}],"version-history":[{"count":0,"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/posts\/19334\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/media\/19335"}],"wp:attachment":[{"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/media?parent=19334"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/categories?post=19334"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/tags?post=19334"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}