{"id":7094,"date":"2013-10-19T07:48:01","date_gmt":"2013-10-19T07:48:01","guid":{"rendered":"http:\/\/blogs.agu.org\/landslideblog\/?p=7094"},"modified":"2013-10-19T07:48:01","modified_gmt":"2013-10-19T07:48:01","slug":"aerial-images-of-izu-oshima-debris-flows","status":"publish","type":"post","link":"https:\/\/blogs.agu.org\/landslideblog\/2013\/10\/19\/aerial-images-of-izu-oshima-debris-flows\/","title":{"rendered":"Aerial images of the Izu-Oshima debris flows in Japan"},"content":{"rendered":"<p>Thanks to @levrem on Twitter (for which I use @davepetley ), my attention has been drawn to an excellent Google crisis map of the <a href=\"https:\/\/blogs.agu.org\/landslideblog\/2013\/10\/18\/izu-oshima-debris-flow\/\">Izu-Oshima debris flows in Japan<\/a>. This site provides both vertical aerial photographs and oblique images of the landslides.\u00a0 So let&#8217;s start with an over view of the landslide complex from the <a href=\"http:\/\/google.org\/crisismap\/japan?hl=en-GB&amp;llbox=34.8272%2C34.6556%2C139.5109%2C139.2836&amp;t=ROADMAP&amp;layers=28%2C3%2C27%2C24%3A56%2C26%2C6%2C23%2C22%2C7%2C8%2C9%2C10%2C11%2Clayer2%2C16%2Clayer5%2Clayer1%2C17%2C18%2C19%2C20%2C21%2Clayer7%2Clayer8%2C12%2Clayer4%2C15%2C14%2C13%2C30%3A100\">crisis map<\/a>:<\/p>\n<p style=\"text-align: center;\"><a href=\"https:\/\/blogs.agu.org\/landslideblog\/files\/2013\/10\/13_10-Wipha-7.png\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-7095\" alt=\"Izu-Oshima debris flows\" src=\"https:\/\/blogs.agu.org\/landslideblog\/files\/2013\/10\/13_10-Wipha-7-e1382165883276.png\" width=\"640\" height=\"318\" \/><\/a>..<\/p>\n<p>Now let&#8217;s take a closer look at the source area of the landslides:<\/p>\n<p style=\"text-align: center;\"><a href=\"https:\/\/blogs.agu.org\/landslideblog\/files\/2013\/10\/13_10-Wipha-8.png\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-7096\" alt=\"Izu-Oshima debris flows\" src=\"https:\/\/blogs.agu.org\/landslideblog\/files\/2013\/10\/13_10-Wipha-8-e1382166164360.png\" width=\"640\" height=\"500\" \/><\/a>..<\/p>\n<p>The <a href=\"http:\/\/google.org\/crisismap\/japan?hl=en-GB&amp;llbox=34.8272%2C34.6556%2C139.5109%2C139.2836&amp;t=ROADMAP&amp;layers=28%2C3%2C27%2C24%3A56%2C26%2C6%2C23%2C22%2C7%2C8%2C9%2C10%2C11%2Clayer2%2C16%2Clayer5%2Clayer1%2C17%2C18%2C19%2C20%2C21%2Clayer7%2Clayer8%2C12%2Clayer4%2C15%2C14%2C13%2C30%3A100\">Google Crisis map<\/a> also has an <a href=\"http:\/\/mw1.google.com\/crisisresponse\/2013-japan-typhoon\/photos\/DSC00490.JPG\">oblique aerial image of the landslides<\/a> (and several others):<\/p>\n<p style=\"text-align: center;\"><a href=\"https:\/\/blogs.agu.org\/landslideblog\/files\/2013\/10\/13_10-Wipha-9.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-7098\" alt=\"Izu-Oshima debris flows\" src=\"https:\/\/blogs.agu.org\/landslideblog\/files\/2013\/10\/13_10-Wipha-9.jpg\" width=\"480\" height=\"520\" srcset=\"https:\/\/blogs.agu.org\/landslideblog\/files\/2013\/10\/13_10-Wipha-9.jpg 480w, https:\/\/blogs.agu.org\/landslideblog\/files\/2013\/10\/13_10-Wipha-9-276x300.jpg 276w\" sizes=\"auto, (max-width: 480px) 100vw, 480px\" \/><\/a>..<\/p>\n<p>Several people have asked why I find these landslides so surprising.\u00a0 It is clear from the images above that this landslide actual consisted of multiple landslide events all feeding into a two distinct major debris flows.\u00a0 This in itself is not unusual.\u00a0 What is surprising here is that these individual landslides have in effect failed the entire hillside &#8211; i.e. it is their proximity that I find surprising.\u00a0 There may be a number of explanations &#8211; the remarkable rainfall event (total rainfall is <a href=\"http:\/\/www.liveinsurancenews.com\/typhoon-wipha-causes-flooding-mudslides-izu-oshima-dissipating-air\/8530112\/\">reported to have been<\/a> 824 mm, with a peak intensity of 122.5 mm in an hour), the presence on the slopes of soils formed from volcanic ash, and the presence of the road (the close proximity of the crowns of the landslides and the road at the top of the slope is an interesting aspect of this).<\/p>\n<p>The death toll from the landslides is now 27 people, with searches continuing for those who are still missing.\u00a0 The huge impact of these landslides can be seen by comparing these images, before and after the debris flows:<\/p>\n<p>Before:<\/p>\n<p style=\"text-align: center;\"><a href=\"https:\/\/blogs.agu.org\/landslideblog\/files\/2013\/10\/13_10-Wipha-10.png\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-7099\" alt=\"Izu-Oshima debris flows\" src=\"https:\/\/blogs.agu.org\/landslideblog\/files\/2013\/10\/13_10-Wipha-10-e1382167951261.png\" width=\"640\" height=\"324\" \/><\/a>..<\/p>\n<p>And after:<\/p>\n<p style=\"text-align: center;\"><a href=\"https:\/\/blogs.agu.org\/landslideblog\/files\/2013\/10\/13_10-Wipha-11.png\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-7100\" alt=\"Izu-Oshima debris flows\" src=\"https:\/\/blogs.agu.org\/landslideblog\/files\/2013\/10\/13_10-Wipha-11-e1382168039416.png\" width=\"640\" height=\"326\" \/><\/a><\/p>\n<p>..<\/p>\n<p>Unfortunately this area is likely to get more heavy rainfall in the next few days, and the <a href=\"http:\/\/www.usno.navy.mil\/NOOC\/nmfc-ph\/RSS\/jtwc\/warnings\/wp2613.gif\">track of Typhoon Francisco<\/a> suggests that could also pass close to this area.<\/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>Aerial images of the Izu-Oshima debris flows in Japan, triggered by typhoon Wipha, reveal multiple shallow landslides that formed two major debris flows<!-- 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":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-7094","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"_links":{"self":[{"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/posts\/7094","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=7094"}],"version-history":[{"count":0,"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/posts\/7094\/revisions"}],"wp:attachment":[{"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/media?parent=7094"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/categories?post=7094"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/tags?post=7094"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}