{"id":9608,"date":"2015-12-16T22:14:12","date_gmt":"2015-12-17T03:14:12","guid":{"rendered":"http:\/\/all-geo.org\/highlyallochthonous\/wp-content\/uploads\/2015\/12\/16_Simplified-Ocean-Ridges.png"},"modified":"2016-01-13T10:39:20","modified_gmt":"2016-01-13T15:39:20","slug":"16_simplified-ocean-ridges","status":"inherit","type":"attachment","link":"https:\/\/all-geo.org\/highlyallochthonous\/16_simplified-ocean-ridges\/","title":{"rendered":"16th December &#8211; major spreading ridges of the modern world"},"author":2,"featured_media":0,"comment_status":"open","ping_status":"closed","template":"","meta":[],"class_list":["post-9608","attachment","type-attachment","status-inherit","hentry"],"description":{"rendered":"<p class=\"attachment\"><a href='https:\/\/all-geo.org\/highlyallochthonous\/wp-content\/uploads\/2015\/12\/16_Simplified-Ocean-Ridges.png'><img loading=\"lazy\" decoding=\"async\" width=\"300\" height=\"199\" src=\"https:\/\/all-geo.org\/highlyallochthonous\/wp-content\/uploads\/2015\/12\/16_Simplified-Ocean-Ridges-300x199.png\" class=\"attachment-medium size-medium\" alt=\"\" srcset=\"https:\/\/all-geo.org\/highlyallochthonous\/wp-content\/uploads\/2015\/12\/16_Simplified-Ocean-Ridges-300x199.png 300w, https:\/\/all-geo.org\/highlyallochthonous\/wp-content\/uploads\/2015\/12\/16_Simplified-Ocean-Ridges-600x398.png 600w, https:\/\/all-geo.org\/highlyallochthonous\/wp-content\/uploads\/2015\/12\/16_Simplified-Ocean-Ridges.png 800w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/a><\/p>\n"},"caption":{"rendered":"<p><strong>Chris: <\/strong>In the world&#8217;s ocean basins, <a href=\"https:\/\/all-geo.org\/highlyallochthonous\/2013\/09\/scenic-saturday-our-stripy-oceans-explained-50-years-ago-today\/\">new tectonic plate is created at spreading ridges<\/a> in the middle of the ocean basins, and old plate is returned to the mantle at <a href=\"https:\/\/all-geo.org\/highlyallochthonous\/?attachment_id=9548\">subduction zones<\/a>. Studying the rate at which oceanic crust is produced at the major ridges is therefore a good measure of how quickly the planet is turning itself inside out. <\/p>\n<p>To calculate this rate, you need the endpoints of each ridge and the <a href=\"https:\/\/all-geo.org\/highlyallochthonous\/?attachment_id=9594\">rotation pole<\/a> for the relative motion of the plates on either side of the ridge. Plotting just the endpoints produces a greatly simplified map of the global ridge system, as shown here. <\/p>\n<p>If you do the calculation, the average spreading rate works out at just under 5 centimetres a year. Put another way, every year these ridges builds about 2.5 square kilometres of new plate. <\/p>\n<p><strong><a href=\"https:\/\/all-geo.org\/highlyallochthonous\/2015\/12\/a-highly-allochthonous-advent-calendar\/\">Return to the Advent Calendar<\/a><\/strong> <a href=\"https:\/\/all-geo.org\/highlyallochthonous\/16_simplified-ocean-ridges\/\">Continue reading <span class=\"meta-nav\">&rarr;<\/span><\/a><\/p>\n"},"alt_text":"","media_type":"image","mime_type":"image\/png","media_details":{"width":800,"height":531,"file":"2015\/12\/16_Simplified-Ocean-Ridges.png","sizes":{"thumbnail":{"file":"16_Simplified-Ocean-Ridges-150x150.png","width":150,"height":150,"mime_type":"image\/png","source_url":"https:\/\/all-geo.org\/highlyallochthonous\/wp-content\/uploads\/2015\/12\/16_Simplified-Ocean-Ridges-150x150.png"},"medium":{"file":"16_Simplified-Ocean-Ridges-300x199.png","width":300,"height":199,"mime_type":"image\/png","source_url":"https:\/\/all-geo.org\/highlyallochthonous\/wp-content\/uploads\/2015\/12\/16_Simplified-Ocean-Ridges-300x199.png"},"large":{"file":"16_Simplified-Ocean-Ridges-600x398.png","width":600,"height":398,"mime_type":"image\/png","source_url":"https:\/\/all-geo.org\/highlyallochthonous\/wp-content\/uploads\/2015\/12\/16_Simplified-Ocean-Ridges-600x398.png"},"wptouch-new-thumbnail":{"file":"16_Simplified-Ocean-Ridges-144x144.png","width":144,"height":144,"mime_type":"image\/png","source_url":"https:\/\/all-geo.org\/highlyallochthonous\/wp-content\/uploads\/2015\/12\/16_Simplified-Ocean-Ridges-144x144.png"},"post-thumbnail":{"file":"16_Simplified-Ocean-Ridges-800x198.png","width":800,"height":198,"mime_type":"image\/png","source_url":"https:\/\/all-geo.org\/highlyallochthonous\/wp-content\/uploads\/2015\/12\/16_Simplified-Ocean-Ridges-800x198.png"},"full":{"file":"16_Simplified-Ocean-Ridges.png","width":800,"height":531,"mime_type":"image\/png","source_url":"https:\/\/all-geo.org\/highlyallochthonous\/wp-content\/uploads\/2015\/12\/16_Simplified-Ocean-Ridges.png"}},"image_meta":{"aperture":0,"credit":"","camera":"","caption":"","created_timestamp":0,"copyright":"","focal_length":0,"iso":0,"shutter_speed":0,"title":"","orientation":0}},"post":null,"source_url":"https:\/\/all-geo.org\/highlyallochthonous\/wp-content\/uploads\/2015\/12\/16_Simplified-Ocean-Ridges.png","filename":"16_Simplified-Ocean-Ridges.png","filesize":368188,"_links":{"self":[{"href":"https:\/\/all-geo.org\/highlyallochthonous\/wp-json\/wp\/v2\/media\/9608","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/all-geo.org\/highlyallochthonous\/wp-json\/wp\/v2\/media"}],"about":[{"href":"https:\/\/all-geo.org\/highlyallochthonous\/wp-json\/wp\/v2\/types\/attachment"}],"author":[{"embeddable":true,"href":"https:\/\/all-geo.org\/highlyallochthonous\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/all-geo.org\/highlyallochthonous\/wp-json\/wp\/v2\/comments?post=9608"}]}}