{"id":29207,"date":"2018-11-09T07:50:36","date_gmt":"2018-11-09T07:50:36","guid":{"rendered":"https:\/\/blogs.agu.org\/landslideblog\/?p=29207"},"modified":"2018-11-09T07:50:36","modified_gmt":"2018-11-09T07:50:36","slug":"hokkaido-iburi-tobu-earthquake-1","status":"publish","type":"post","link":"https:\/\/blogs.agu.org\/landslideblog\/2018\/11\/09\/hokkaido-iburi-tobu-earthquake-1\/","title":{"rendered":"Landslides from the M=6.7 6th September 2018 Hokkaido Iburi-Tobu Earthquake &#8211; a first technical report"},"content":{"rendered":"<h4>Landslides from the M=6.7 6th September 2018 Hokkaido Iburi-Tobu Earthquake &#8211; a first technical report<\/h4>\n<p>On 6th September 2018 a M=6.7 earthquake struck Hokkaido in Japan. This event, now known as the Hokkaido Iburi-Tobu Earthquake, was remarkable for the number of landslides that it triggered. <a href=\"https:\/\/blogs.agu.org\/landslideblog\/2018\/09\/06\/landslides-6th-september-2018-hokkaido-earthquake\/\">I posted extensively about it at the time<\/a>, <a href=\"https:\/\/blogs.agu.org\/landslideblog\/2018\/09\/11\/2018-hokkaido-eastern-iburi-earthquake\/\">and thereafter<\/a>. The journal <em><a href=\"https:\/\/link.springer.com\/journal\/10346\">Landslides<\/a><\/em> has an initial short report about the landslides triggered by this event (<a href=\"https:\/\/doi.org\/10.1007\/s10346-018-1092-z\">Yamagishi and Yamazaki 2018<\/a>).\u00a0 The key points that they note include:-<\/p>\n<ul>\n<li>Landslides claimed 36 lives out of a total of 41 fatalities in total, thus representing the most significant impact of the earthquake.<\/li>\n<li>Landslides were triggered over a 20 x 20 km area in the vicinity of Atsuma Town.<\/li>\n<li>To date over 6,000 landslides triggered by the earthquake have been mapped.<\/li>\n<li>Interestingly however, only about 1,000 debris deposits have been identified.\u00a0 Whilst this might seem paradoxical, it is a sign that many of the landslides combined to form a single, complex deposit.<\/li>\n<li>Most of the landslides were shallow failures, with a planar or spoon-shaped rupture surface.<\/li>\n<li>Most of the landslides occurred in airfall ash and pumice layers, typically 1.5 m thick, erupted from Tarumai volcano at about 9000 years BP.<\/li>\n<\/ul>\n<p>The authors speculate that the large number of landslides triggered by this earthquake was a result of the vulnerability of the local geology to seismically-induced triggering, possibly compounded by high groundwater levels as a result of the recent passage of Typhoon Jebi, which had deposited over 100 mm of rainfall in the preceding three days.<\/p>\n<div id=\"attachment_29209\" style=\"width: 650px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-29209\" class=\"size-full wp-image-29209\" src=\"https:\/\/blogs.agu.org\/landslideblog\/files\/2018\/11\/18_11-Japan-1-e1541749123901.jpg\" alt=\"Hokkaido Iburi-Tobu Earthquake\" width=\"640\" height=\"451\" \/><p id=\"caption-attachment-29209\" class=\"wp-caption-text\"><a href=\"https:\/\/www.planet.com\/\">Planet Labs image<\/a> showing landslides triggered by the 6 September 2018 M=6.7 Hokkaido Iburi-Tobu Earthquake. 4-band Planetscope image collected on 20th October 2018, used with permission.<\/p><\/div>\n<p>.<\/p>\n<h4>Reference<\/h4>\n<p>Yamagishi, H. &amp; Yamazaki, F. 2018.\u00a0 <a href=\"https:\/\/doi.org\/10.1007\/s10346-018-1092-z\">Landslides by the 2018 Hokkaido Iburi-Tobu Earthquake on September 6<\/a>. <a href=\"https:\/\/link.springer.com\/journal\/10346\"><em>Landslides<\/em><\/a>. <a href=\"https:\/\/doi.org\/10.1007\/s10346-018-1092-z\">https:\/\/doi.org\/10.1007\/s10346-018-1092-z<\/a><\/p>\n<p>Planet Team (2018). Planet Application Program Interface: In Space for Life on Earth. San Francisco, CA. <a href=\"https:\/\/www.planet.com\/\">https:\/\/www.planet.com\/<\/a><\/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>On 6th September 2018 the M=6.7 Hokkaido Iburi-Tobu earthquake struck Hokkaido in Japan. The earthquake triggered over 6000 landslides, killing 36 people<!-- 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":29209,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[537],"tags":[23,881,469,361,192,17],"class_list":["post-29207","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-earthquake-induced-landslide","tag-earthquake","tag-east-asia","tag-featured","tag-japan","tag-paper","tag-research"],"_links":{"self":[{"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/posts\/29207","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=29207"}],"version-history":[{"count":0,"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/posts\/29207\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/media\/29209"}],"wp:attachment":[{"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/media?parent=29207"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/categories?post=29207"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/tags?post=29207"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}