{"id":35594,"date":"2020-11-18T07:33:06","date_gmt":"2020-11-18T07:33:06","guid":{"rendered":"https:\/\/blogs.agu.org\/landslideblog\/?p=35594"},"modified":"2020-11-18T07:33:06","modified_gmt":"2020-11-18T07:33:06","slug":"argaga-1","status":"publish","type":"post","link":"https:\/\/blogs.agu.org\/landslideblog\/2020\/11\/18\/argaga-1\/","title":{"rendered":"Argaga: the major rockfall on La Gomera on 14 November 2020"},"content":{"rendered":"<h4>Argaga: the major rockfall on La Gomera on 14 November 2020<\/h4>\n<p>Videos were widely shared on Twitter over the weekend showing remarkable footage of a major rock slope collapse at Argaga on the Spanish island of La Gomera on 14 November 2020.\u00a0 This is a large, near vertical collapse event, with the debris falling onto a road and into the sea.\u00a0 Fortunately no-one was killed.<\/p>\n<p>There are actually two videos of this event, both capturing slightly different elements.\u00a0 Together they provide a very useful documentation of the failure.\u00a0 <a href=\"https:\/\/www.youtube.com\/watch?v=nrgs1GLNf9c\">The first starts about a minute before the collapse<\/a>.\u00a0 When the video starts there is some dust close to the rock slope.\u00a0 Over time, isolated (though not trivial) falls occur across the slope:-<\/p>\n<iframe loading=\"lazy\" title=\"DERRUMBE DE ARGAGA 14.11.2020\" width=\"800\" height=\"450\" src=\"https:\/\/www.youtube.com\/embed\/nrgs1GLNf9c?feature=oembed\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture\" allowfullscreen><\/iframe>\n<p>.<\/p>\n<p>The person collecting this video is clearly concerned about the potential for a displacement wave (sensibly), and so evacuates when the collapse occurs.<\/p>\n<p><a href=\"https:\/\/www.youtube.com\/watch?v=SsGyzhBHtn8\">The second catches less of the precursory activity<\/a>, although the main collapse is well constrained:<\/p>\n<iframe loading=\"lazy\" title=\"Importante desprendimiento en el acceso a la Playa de Argaga\" width=\"800\" height=\"450\" src=\"https:\/\/www.youtube.com\/embed\/SsGyzhBHtn8?feature=oembed\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture\" allowfullscreen><\/iframe>\n<p>.<\/p>\n<p>But this one captures the aftermath of the landslide, including the displacement wave that is generated by the collapse, as well as the very impressive cloud of dust.<\/p>\n<p>In this case failure has been controlled by near vertical joints in the volcanic rocks.\u00a0 Collapse would have been controlled by the development of new fractures that linked the existing joints together to create the release surface.\u00a0 As this proceeded the rock mass crept and deformed at an accelerating rate.\u00a0 It is this deformation that pops off the precursory rockfalls.\u00a0 These precursors are of course invaluable as they often warn people in the vicinity that failure is developing, and in this case it also meant that people started to video the slope.<\/p>\n<p><a href=\"https:\/\/elpais.com\/espana\/2020-11-14\/un-derrumbe-en-un-acantilado-sepulta-varias-caravanas-en-la-gomera.html\">El Pais reports that rockfalls are common on this stretch of cliff<\/a>.\u00a0 The owners of this vehicle might consider themselves somewhat fortunate:<\/p>\n<div id=\"attachment_35601\" style=\"width: 693px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-35601\" class=\"size-full wp-image-35601\" src=\"https:\/\/blogs.agu.org\/landslideblog\/files\/2020\/11\/20_11-Argaga-1.jpg\" alt=\"Argaga rockfall\" width=\"683\" height=\"450\" srcset=\"https:\/\/blogs.agu.org\/landslideblog\/files\/2020\/11\/20_11-Argaga-1.jpg 683w, https:\/\/blogs.agu.org\/landslideblog\/files\/2020\/11\/20_11-Argaga-1-300x198.jpg 300w\" sizes=\"auto, (max-width: 683px) 100vw, 683px\" \/><p id=\"caption-attachment-35601\" class=\"wp-caption-text\">The aftermath of the rockfall at Argaga. <a href=\"https:\/\/www.europapress.es\/islas-canarias\/noticia-plantean-construir-embarcadero-facilitar-accesibilidad-argaga-20201115154827.html\">Image by INVOLCAN via Europapress<\/a>.<\/p><\/div>\n<p>.<\/p>\n<h4>Quickslide 1: Hurricane Iota has made landfall in Central America<\/h4>\n<p><a href=\"https:\/\/www.newsamericasnow.com\/central-america-news-hurricane-iota-death-toll\/\">Hurricane Iota crossed the coast in Central America yesterday<\/a>, bringing exceptional rainfall and very high winds.\u00a0 We await to see the level of damage that it has caused, but landslides are inevitable.<\/p>\n<p>.<\/p>\n<h4>Quickslide 2: Investigations of the peat landslides in the Republic of Ireland<\/h4>\n<p><a href=\"https:\/\/www.independent.ie\/news\/exactly-what-we-were-afraid-of-inquiries-launched-into-landslides-amid-fears-of-serious-pollution-39754870.html\">The Independent in Ireland has a good article<\/a> on the aftermath of the two <a href=\"https:\/\/blogs.agu.org\/landslideblog\/2020\/11\/17\/mount-eagle\/\">peat slides in the Republic of Ireland last week<\/a>.\u00a0 I will be interested to see what the investigations find.<\/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>Argaga: two impressive videos of the major coastal rockfall on the Spanish island of La Gomera on 14 November 2020 <!-- 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":35601,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":"","_members_access_role":[],"_members_access_error":""},"categories":[29],"tags":[1166,469,963,527,249],"class_list":["post-35594","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-landslide-video","tag-canary-islands","tag-featured","tag-landslide-video","tag-rockfalls","tag-spain"],"_links":{"self":[{"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/posts\/35594","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=35594"}],"version-history":[{"count":0,"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/posts\/35594\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/media\/35601"}],"wp:attachment":[{"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/media?parent=35594"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/categories?post=35594"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/tags?post=35594"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}