{"id":7404,"date":"2013-12-13T17:20:23","date_gmt":"2013-12-13T17:20:23","guid":{"rendered":"http:\/\/blogs.agu.org\/landslideblog\/?p=7404"},"modified":"2013-12-13T17:23:08","modified_gmt":"2013-12-13T17:23:08","slug":"utah-rockfall-1","status":"publish","type":"post","link":"https:\/\/blogs.agu.org\/landslideblog\/2013\/12\/13\/utah-rockfall-1\/","title":{"rendered":"The Utah rockfall tragedy – the importance of interpreting clues in the landscape"},"content":{"rendered":"

The Utah rockfall event<\/h4>\n

In the ironically named Rockville in Utah, a rockfall last night crushed a house, killing the two inhabitants.\u00a0 The Utah rockfall was a hard rock slope failure on a large-scale.\u00a0 The image below (from the Daily Mail<\/a> – who incidentally have an interesting view of the size of an elephant!) shows that this was a massive block:<\/p>\n

\"Utah<\/a>

http:\/\/www.dailymail.co.uk\/news\/article-2523067\/Boulder-size-elephant-crushes-entire-house-instantly-kills-inhabitants-Utah-landslide.html<\/p><\/div>\n

..<\/p>\n

The same article also has a view of the house before the collapse:<\/p>\n

\"Utah<\/a>

http:\/\/www.dailymail.co.uk\/news\/article-2523067\/Boulder-size-elephant-crushes-entire-house-instantly-kills-inhabitants-Utah-landslide.html<\/p><\/div>\n

..<\/p>\n

Implications of the Utah Rockfall for hazard assessment<\/h4>\n

This tragedy does serve to illustrate a key point about rockfall hazard assessment, which is that debris from earlier events often gives a pretty good indication of the hazard.\u00a0 In allowing the selection of a site close to a rock cliff, a key first consideration should be the level of rockfall hazard, as indicated by boulders from previous events.\u00a0 the image below is from Google Earth, dated earlier this year.\u00a0 I have highlighted at the crest of the slope potentially unstable blocks of rock, and at the toe the house that the boulder struck:<\/p>\n

\"Utah<\/a>..<\/p>\n

A zoom into the area around the house shows that it was surrounded by very large boulders – these are of course the debris from previous very large rock slope collapses (and one of them is very clear in the photograph of the house above):<\/p>\n

\"Utah<\/a><\/p>\n

..<\/p>\n

The presence of these boulders should have been at least an initial flag that this was a potentially dangerous location.\u00a0 Coupled with the structure at the top of the slope, the situation looks still worse.<\/p>\n

An interesting challenge to the authorities in the aftermath of the Utah rockfall tragedy will be assessing the safety of the remaining houses at the foot of the slope.<\/p>\n","protected":false},"excerpt":{"rendered":"

The fatal Utah rockfall yesterday highlights the importance of using geomorphic evidence to highlight dangerous locations below steep slopes<\/p>\n","protected":false},"author":22,"featured_media":7405,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3],"tags":[469,754,246,56,48,535],"class_list":["post-7404","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-landslide-report","tag-featured","tag-hazard-assessment","tag-risk","tag-rockfall","tag-usa","tag-utah"],"_links":{"self":[{"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/posts\/7404","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=7404"}],"version-history":[{"count":0,"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/posts\/7404\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/media\/7405"}],"wp:attachment":[{"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/media?parent=7404"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/categories?post=7404"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/tags?post=7404"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}