{"id":37990,"date":"2021-07-05T08:10:38","date_gmt":"2021-07-05T08:10:38","guid":{"rendered":"https:\/\/blogs.agu.org\/landslideblog\/?p=37990"},"modified":"2021-07-05T10:32:33","modified_gmt":"2021-07-05T10:32:33","slug":"atami-mudslides","status":"publish","type":"post","link":"https:\/\/blogs.agu.org\/landslideblog\/2021\/07\/05\/atami-mudslides\/","title":{"rendered":"The Atami mudslides in Japan"},"content":{"rendered":"<h4>The Atami mudslides in Japan<\/h4>\n<p>Over the weekend there was considerable attention paid to the remarkable videos of the mudflows in Atami, Japan.\u00a0 <a href=\"https:\/\/www.youtube.com\/watch?v=iDOn46equP8\">This one in particular gained traction<\/a>:-<\/p>\n<iframe loading=\"lazy\" title=\"Breaking | 03_July_2021 | Japan Landslide in Atami Izu Resort Shizuoka | Mudslide\" width=\"800\" height=\"450\" src=\"https:\/\/www.youtube.com\/embed\/iDOn46equP8?feature=oembed\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture\" allowfullscreen><\/iframe>\n<p>.<\/p>\n<p>But there are several others, which are helpfully <a href=\"https:\/\/www.youtube.com\/watch?v=hlPxFVDpW6Q\">combined into a compilation here<\/a>:<\/p>\n<iframe loading=\"lazy\" title=\"Dramatic video! LARGEST LANDSLIDE in Atami City, Japan (July 3, 2021)\" width=\"800\" height=\"450\" src=\"https:\/\/www.youtube.com\/embed\/hlPxFVDpW6Q?feature=oembed\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture\" allowfullscreen><\/iframe>\n<p>.<\/p>\n<p>I particularly draw your attention to the excerpt that begins at 8 minutes 16 seconds into the second video (the same sequence appears in the first video too).<\/p>\n<p>The main, extremely violent, footage is a particularly nasty example of a channelised flow, common in steep terrain that is subject to extreme rainfall.\u00a0 Long term readers of this blog will remember the classic examples from <a href=\"https:\/\/blogs.agu.org\/landslideblog\/2008\/06\/12\/debris-flow-video-from-hong-kong\/\">Lantau in Hong Kong in 2008<\/a> and <a href=\"https:\/\/blogs.agu.org\/landslideblog\/2015\/07\/13\/umyeonsan\/\">South Korea in 2011<\/a> for example, but there are many, many other examples.<\/p>\n<p>The Google Earth image below shows the general location of the Atami disaster.\u00a0 I have placed the marker on what is, I think, the location of the prominent red building in the main video:-<\/p>\n<div id=\"attachment_37999\" style=\"width: 809px\" class=\"wp-caption alignnone\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-37999\" class=\"wp-image-37999 \" src=\"https:\/\/blogs.agu.org\/landslideblog\/files\/2021\/07\/21_07-Atami-2a-scaled.jpg\" alt=\"Google Earth image showing the presumed location of the Atami mudslide\" width=\"799\" height=\"552\" srcset=\"https:\/\/blogs.agu.org\/landslideblog\/files\/2021\/07\/21_07-Atami-2a-scaled.jpg 2560w, https:\/\/blogs.agu.org\/landslideblog\/files\/2021\/07\/21_07-Atami-2a-300x207.jpg 300w, https:\/\/blogs.agu.org\/landslideblog\/files\/2021\/07\/21_07-Atami-2a-1024x707.jpg 1024w, https:\/\/blogs.agu.org\/landslideblog\/files\/2021\/07\/21_07-Atami-2a-768x530.jpg 768w, https:\/\/blogs.agu.org\/landslideblog\/files\/2021\/07\/21_07-Atami-2a-1536x1060.jpg 1536w, https:\/\/blogs.agu.org\/landslideblog\/files\/2021\/07\/21_07-Atami-2a-2048x1414.jpg 2048w\" sizes=\"auto, (max-width: 799px) 100vw, 799px\" \/><p id=\"caption-attachment-37999\" class=\"wp-caption-text\">Google Earth image showing the presumed location of the Atami mudslide<\/p><\/div>\n<p>.<\/p>\n<p>Some important insight into this event is <a href=\"https:\/\/twitter.com\/yoshi_kariya\/status\/1411203504220217353?s=20\">provided in a tweet<\/a> by <a href=\"https:\/\/twitter.com\/yoshi_kariya\">Yoshi Kariya<\/a>:<\/p>\n<blockquote class=\"twitter-tweet\" data-width=\"500\" data-dnt=\"true\">\n<p lang=\"ja\" dir=\"ltr\"><a href=\"https:\/\/twitter.com\/hashtag\/%E7%86%B1%E6%B5%B7?src=hash&amp;ref_src=twsrc%5Etfw\">#\u71b1\u6d77<\/a> <a href=\"https:\/\/twitter.com\/hashtag\/%E4%BC%8A%E8%B1%86%E5%B1%B1?src=hash&amp;ref_src=twsrc%5Etfw\">#\u4f0a\u8c46\u5c71<\/a> <a href=\"https:\/\/twitter.com\/hashtag\/%E5%9C%9F%E7%9F%B3%E6%B5%81?src=hash&amp;ref_src=twsrc%5Etfw\">#\u571f\u77f3\u6d41<\/a> \u767a\u751f\u306e\u8c37\u3002\u659c\u9762\u5d29\u58ca\u306e\u6700\u524d\u7dda\u3067\u3042\u308b\u8c37\u982d\u304c\u706b\u5c71\u659c\u9762\u3092\u523b\u3093\u3067\u3044\u304f\u3064\u3082\u4f38\u3073\u3001\u8c37\u5e95\u3067\u306f\u5806\u7a4d\u3057\u305f\u904e\u53bb\u306e\u571f\u77f3\u6d41\u30fb\u5730\u3059\u3079\u308a\u5806\u7a4d\u7269\u304c\u68da\u7530\u72b6\u306b\u9020\u6210\u3055\u308c\u305f\u69d8\u5b50\u304c\u308f\u304b\u308b\u3002\u6d41\u57df\u4e0a\u90e8\u306e\u5c3e\u6839\u306b\u9020\u6210\u5730\u304c\u3042\u3063\u305f\u3088\u3046\u3060\uff3b\u5730\u7406\u96622017\u5e74\u5199\u771f\uff3d\u3002 <a href=\"https:\/\/t.co\/aRCbV1pQNJ\">pic.twitter.com\/aRCbV1pQNJ<\/a><\/p>\n<p>&mdash; \u82c5\u8c37\u611b\u5f66 Yoshi Kariya (@yoshi_kariya) <a href=\"https:\/\/twitter.com\/yoshi_kariya\/status\/1411203504220217353?ref_src=twsrc%5Etfw\">July 3, 2021<\/a><\/p><\/blockquote>\n<p><script async src=\"https:\/\/platform.twitter.com\/widgets.js\" charset=\"utf-8\"><\/script><\/p>\n<p>.<\/p>\n<p>A translation of the text is:<\/p>\n<p><em>Valley of occurrence. It can be seen that the valley head, which is the forefront of slope failure, extends several times along the volcanic slope, and the past debris flow and landslide deposits that have accumulated at the bottom of the valley are formed in the shape of a terraced rice field. It seems that there was a land on the ridge in the upper part of the basin [Geographical Survey Institute 2017 photo].<\/em><\/p>\n<p><a href=\"https:\/\/www.youtube.com\/watch?v=wT488kWVRBY\">Shizuoka Prefecture has released a drone video that shows the landslide at the crown of the mudslide<\/a>:<\/p>\n<iframe loading=\"lazy\" title=\"\u71b1\u6d77\u571f\u77f3\u6d41\u3000\u9759\u5ca1\u770c\u304c\u300c\u8d77\u70b9\u300d\u306e\u30c9\u30ed\u30fc\u30f3\u64ae\u5f71\u52d5\u753b\u3092\u516c\u958b\" width=\"800\" height=\"450\" src=\"https:\/\/www.youtube.com\/embed\/wT488kWVRBY?feature=oembed\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture\" allowfullscreen><\/iframe>\n<p>.<\/p>\n<p>This suggests that the Atami mudflows started as a conventional landslide high up in the catchment.\u00a0 This is a typical response to very heavy rainfall.\u00a0 The ground will probably have undergone static liquefaction to form the highly mobile flow.\u00a0 Once channelised, it will have entrained water from the channel and deposits within the channel, especially those left from previous landslides, to create this terrifying mudflow.<\/p>\n<p>The destructive power of these events is much greater than that of a river flood as the density of earth materials is much higher.<\/p>\n<p>There are two interesting elements to this landslide.\u00a0 The first is that the initial failure appears to be quite deep-seated.\u00a0 The second is the presence of the road right at the headscarp.\u00a0 In other cases, <a href=\"http:\/\/www.ijege.uniroma1.it\/rivista\/5th-international-conference-on-debris-flow-hazards-mitigation-mechanics-prediction-and-assessment\/topic-1-debris-flow-occurrence-and-initiation\/the-1998-sarno-landslides-conflicting-interpretations-of-a-natural-event\/ijege-11_bs-guadagno-et-alii.pdf\">most notably the Sarno landslides in Italy<\/a>, roads have played a key role in the destabilisation of the slope.\u00a0 Given the deep-seated nature of the landslide, that may not be the case here, but it is an interesting juxtaposition.<\/p>\n<p>Japan has high quality landslide management programmes and amongst the best engineering prowess for managing these hazards.\u00a0 However, the combination of the geological setting, the climate and the high population levels means that entirely preventing these events is impossible.<\/p>\n<p>Sadly, but unsurprisingly perhaps, the number of people reported missing at Atami has jumped overnight.\u00a0 <a href=\"https:\/\/www.reuters.com\/world\/asia-pacific\/three-dead-113-missing-japan-after-heavy-rains-trigger-landslides-2021-07-05\/\">Latest reports suggest that there are three known fatalities but as many as 80 people may be missing<\/a>.\u00a0 Hopefully this will reduce in the next few days as people away from home are traced, but the losses may well be high.<\/p>\n<p>&nbsp;<\/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>The Atami mudslides in Japan Over the weekend there was considerable attention paid to the remarkable videos of the mudflows in Atami, Japan.\u00a0 This one in particular gained traction:- . But there are several others, which are helpfully combined into a compilation here: . I particularly draw your attention to the excerpt that begins at 8 minutes 16 seconds into the second video (the same sequence appears in the first &hellip;<!-- 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":37999,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[57,881,469,361,959,641],"class_list":["post-37990","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-uncategorized","tag-debris-flow","tag-east-asia","tag-featured","tag-japan","tag-landslide-report","tag-mudflow"],"_links":{"self":[{"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/posts\/37990","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=37990"}],"version-history":[{"count":0,"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/posts\/37990\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/media\/37999"}],"wp:attachment":[{"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/media?parent=37990"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/categories?post=37990"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/tags?post=37990"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}