{"id":35962,"date":"2020-12-30T09:40:18","date_gmt":"2020-12-30T09:40:18","guid":{"rendered":"https:\/\/blogs.agu.org\/landslideblog\/?p=35962"},"modified":"2021-01-01T19:42:09","modified_gmt":"2021-01-01T19:42:09","slug":"gjerdrum-1","status":"publish","type":"post","link":"https:\/\/blogs.agu.org\/landslideblog\/2020\/12\/30\/gjerdrum-1\/","title":{"rendered":"Gjerdrum: a quick clay landslide disaster in Norway this morning"},"content":{"rendered":"

Gjerdrum: a quick clay landslide disaster in Norway this morning<\/h4>\n

The latest update on the Gjerdrum landslide is in a new post<\/a><\/h4>\n

Overnight, a large quick clay landslide has struck the village of Ask in the municipality of Gjerdurm<\/a> in Norway.\u00a0 News reports from this landslide are a little confused as I write this – unsurprisingly – but it is clear that the slide has swept away a number of houses.\u00a0 Reports suggest that up to nine people might have been injured.\u00a0 About 700 people have been evacuated so far.\u00a0 It is reported that 14 buildings have been lost to date.\u00a0 Update:<\/strong> <\/em>as the afternoon ends in Norway reports indicate that 12 people are not accounted for<\/a>, some of whom are children.\u00a0 Unfortunately, the rescue services have not been able to enter the area affected by the landslide.\u00a0 This is the correct decision – this slope is likely to still be highly unstable.\u00a0 A further three houses have been lost during the day.<\/p>\n

Aftenposten has this image of the upper reaches of the quick clay landslide at Gjerdrum<\/a>:-<\/p>\n

\"Gjerdrum

The quick clay landslide at Gjerdrum in Norway. Image from Aftenposten, collected by Foto: 330-skvadronen \/ Hovedredningssentralen<\/a>.<\/p><\/div>\n

.<\/p>\n

The Norwegian Police have described this event as a disaster.\u00a0 The site of the landslide appears to be the area shown in the Google Earth image below – the location is 60.065, 11.036:-<\/p>\n

\"Gjerdrum

Google Earth image showing the site of the 30 December 2020 Gjerdrum landslide in Norway.<\/p><\/div>\n

.<\/h4>\n

Reports indicate that the alert was sounded at about 4 am local time.\u00a0 The landslide remains unstable, and some retrogression of the head scarp is still occurring.\u00a0 It is not clear how far downslope the landslide extends, but the images suggest that this is a very substantial failure.<\/p>\n

Gjerdrum has suffered quick clay (sensitive clay) landslides before.\u00a0 For example, Google Books has a case study of a significant event in 2012<\/a>.<\/p>\n

This is the NVE quick clay hazard map for the area<\/a>:<\/p>\n

\"Quick

NVE Quick Clay hazard map showing the site of the 30 December 2020 Gjerdrum landslide in Norway.<\/p><\/div>\n

.<\/p>\n

The area that has failed is described as being Low hazard but a loosening area<\/del> that is within the source zone for landslides (many thanks to those who have helped me to understand this).\u00a0 However, it is immediately adjacent to an area described as medium hazard.<\/p>\n

VG TV has a video of a house collapsing into the landslide bowl<\/a>.\u00a0 It demonstrates that this is a very large failure (unfortunately I cannot embed this video):-<\/p>\nhttps:\/\/www.vgtv.no\/video\/210593\/vgs-reporter-om-hus-i-jordskredsomraade-staar-delvis-i-loese-lufta<\/a>\n

The Norwegian Police have now released a map showing the area affected by the Gjerdrum landslide (in red).<\/a> The large area with green hatching is the zone that has been evacuated today.<\/p>\n

The latest update on the Gjendrum landslide is in a new post<\/a><\/h4>\n
\"The

The area afftected by the Gjerdrum landslide – map generated by the Norwegian Police<\/a>.<\/p><\/div>\n

The latest update on the Gjerdrum landslide is in a new post<\/a><\/h4>\n","protected":false},"excerpt":{"rendered":"

A quick clay landslide disaster has occurred at Gjerdrum in Norway this morning. There are 14 people unaccounted for, some of whom are children, and 9 people injured. The rescue teams have been unable to enter the landslide zone<\/p>\n","protected":false},"author":22,"featured_media":35965,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3],"tags":[144,469,959,278,30048],"class_list":["post-35962","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-landslide-report","tag-europe","tag-featured","tag-landslide-report","tag-norway","tag-quick-clay-landslide"],"_links":{"self":[{"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/posts\/35962","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=35962"}],"version-history":[{"count":0,"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/posts\/35962\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/media\/35965"}],"wp:attachment":[{"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/media?parent=35962"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/categories?post=35962"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/tags?post=35962"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}