{"id":3954,"date":"2011-11-24T22:32:24","date_gmt":"2011-11-24T22:32:24","guid":{"rendered":"http:\/\/blogs.agu.org\/landslideblog\/?p=3954"},"modified":"2011-11-24T22:33:51","modified_gmt":"2011-11-24T22:33:51","slug":"an-update-on-the-san-pedro-landslide","status":"publish","type":"post","link":"https:\/\/blogs.agu.org\/landslideblog\/2011\/11\/24\/an-update-on-the-san-pedro-landslide\/","title":{"rendered":"A further update on the San Pedro landslide"},"content":{"rendered":"

Ernie Roumelis has very kindly sent me an update on the San Pedro<\/a> landslide<\/a>, which (with his permission) I reproduce here:<\/p>\n

Approximate location is \u00a033.715100\u00b0, -118.312185\u00b0. We have had some heavy rains over the weekend so a nice sized chunk of rock hastened its slip into the ocean last night. Here\u2019s a video clip http:\/\/www.nbclosangeles.com\/news\/local\/San-Pedro-Landslide-Cliff-134238418.html<\/a>. I will look for more footage through the day. The local residents are notably upset. I wish there was a way to let them know that:<\/p>\n

1) For the very long term, yes portions of the area could potentially be unstable.<\/p>\n

2) No, they will not become an island like Catalina (located 35 km south of this region); and<\/p>\n

3) Although Facebook is a wonderful medium for getting messages out quickly, one must take it all with a grain of salt and look a bit further when possible.<\/p>\n

This area consists of a series of marine terraces unconformably sitting on Miocene sedimentary rock (Monterey Formation). The bedrock has been uplifted into an anticline and is now out-of-slope towards the ocean. Ancient landsliding occurred here during the Late Pleistocene and naturally stabilized. Local relative sea levels have also changed, partly due to Pleistocene-Holocene climate shift and partly due to tectonic uplift. As those sea levels have increased through the last several thousand years, the existing landslide toes slowly get eroded.<\/p>\n

Every once in a while, another block slips along and falls into the sea. Last week\u2019s sloughing was a part of that. \u00a0To answer the newsperson\u2019s question in the video clip, I am sure seasonal rains slightly help accelerate the process.<\/p>\n

Here\u2019s some more interesting information on this area. It has had documented movement since the late 1920\u2019s. Most notably the Point Fermin landslide located 600m to the southwest. Here is a nice little virtual tour from Cal State Long Beach (one of the local universities) http:\/\/geology.cnsm.ad.csulb.edu\/VIRTUAL_FIELD\/Palos_Verdes\/fermin.htm<\/a><\/p><\/blockquote>\n

Meanwhile, as Jim Heddingon pointed out in a comment, the Daily Mail has probably the best gallery of images<\/a> of the landslide that I have seen to date, including this one:<\/p>\n

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

At some point in the next few months that large displaced block is going to collapse into the sea, which should be fairly spectacular.<\/p>\n","protected":false},"excerpt":{"rendered":"

A further update on the San Pedro landslide, with information from Ernie Roumelis<\/p>\n","protected":false},"author":22,"featured_media":3955,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3],"tags":[137,134,469,959,48],"class_list":["post-3954","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-landslide-report","tag-california","tag-coastal-erosion","tag-featured","tag-landslide-report","tag-usa"],"_links":{"self":[{"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/posts\/3954","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=3954"}],"version-history":[{"count":0,"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/posts\/3954\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/media\/3955"}],"wp:attachment":[{"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/media?parent=3954"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/categories?post=3954"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/tags?post=3954"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}