{"id":130,"date":"2019-12-05T14:34:42","date_gmt":"2019-12-05T13:34:42","guid":{"rendered":"http:\/\/www.oceanblogs.org\/teachingoceanscience\/?p=130"},"modified":"2020-03-07T19:30:29","modified_gmt":"2020-03-07T18:30:29","slug":"throwback-thursday-can-you-taste-the-difference-or-how-do-you-estimate-salinity","status":"publish","type":"post","link":"https:\/\/www.oceanblogs.org\/teachingoceanscience\/2019\/12\/05\/throwback-thursday-can-you-taste-the-difference-or-how-do-you-estimate-salinity\/","title":{"rendered":"Throwback Thursday: Can you taste the difference? Or how do you estimate salinity?"},"content":{"rendered":"\n<p><em>Today we are looking back at a homework assignment that&nbsp;<a href=\"http:\/\/www.geomar.de\/en\/mitarbeiter\/fb1\/po\/jluebbecke\/\">Joke L\u00fcbbecke<\/a> gave her students 5 years ago, but that\u2019s still interesting &amp; relevant and also a lot of fun! The task is easy: \u201cestimate salinity of this water sample!\u201d. But how do you do that? Here are three different ways to solve the problem<\/em><\/p>\n\n\n\n<p><strong>Estimating salinity as a homework assignment<\/strong><\/p>\n\n\n\n<p>When I gave the second-year oceanography students in my class bottles of salt water and \u2013 without any further instructions &#8211; asked them to find out what the salinity was, I wasn\u2019t really sure what to expect. Would they just take a sip and guess 35? Would they all use the same approach? So when they handed in their solutions in the following week I was very happy to see how creative they had been and how many different things they had tried to get to an answer. For example, they had<\/p>\n\n\n\n<ul class=\"wp-block-list\"><li>Evaporated the water and weighted the dry salt<\/li><\/ul>\n\n\n\n<figure class=\"wp-block-image\"><img loading=\"lazy\" decoding=\"async\" width=\"643\" height=\"384\" src=\"https:\/\/www.oceanblogs.org\/teachingoceanscience\/wp-content\/uploads\/sites\/67\/2020\/01\/Joke_image001.png\" alt=\"\" class=\"wp-image-131\" srcset=\"https:\/\/www.oceanblogs.org\/teachingoceanscience\/wp-content\/uploads\/sites\/67\/2020\/01\/Joke_image001.png 643w, https:\/\/www.oceanblogs.org\/teachingoceanscience\/wp-content\/uploads\/sites\/67\/2020\/01\/Joke_image001-480x287.png 480w\" sizes=\"auto, (max-width: 643px) 100vw, 643px\" \/><figcaption>Evaporating water from salt water and weighing the remaining salt to measure salinity<\/figcaption><\/figure>\n\n\n\n<ul class=\"wp-block-list\"><li>Used differences in buoyancy between salt and fresh water<\/li><\/ul>\n\n\n\n<figure class=\"wp-block-image\"><img loading=\"lazy\" decoding=\"async\" width=\"512\" height=\"388\" src=\"https:\/\/www.oceanblogs.org\/teachingoceanscience\/wp-content\/uploads\/sites\/67\/2020\/01\/Joke_image002.png\" alt=\"\" class=\"wp-image-132\" srcset=\"https:\/\/www.oceanblogs.org\/teachingoceanscience\/wp-content\/uploads\/sites\/67\/2020\/01\/Joke_image002.png 512w, https:\/\/www.oceanblogs.org\/teachingoceanscience\/wp-content\/uploads\/sites\/67\/2020\/01\/Joke_image002-480x364.png 480w\" sizes=\"auto, (max-width: 512px) 100vw, 512px\" \/><figcaption>Measuring salinity by comparing buoyancy with known samples<\/figcaption><\/figure>\n\n\n\n<ul class=\"wp-block-list\"><li>Measured the electric resistance of the sample, then tried to mix a solution with the same resistance by adding more and more (defined quantities of) salt to a fresh water sample<\/li><\/ul>\n\n\n\n<p>or simply<\/p>\n\n\n\n<figure class=\"wp-block-image\"><img loading=\"lazy\" decoding=\"async\" width=\"297\" height=\"288\" src=\"https:\/\/www.oceanblogs.org\/teachingoceanscience\/wp-content\/uploads\/sites\/67\/2020\/01\/Joke_image003.png\" alt=\"\" class=\"wp-image-133\" \/><figcaption>Measuring salinity by measuring the resistance of the sample and reproducing a sample with known salinity and the same resistance<\/figcaption><\/figure>\n\n\n\n<ul class=\"wp-block-list\"><li>Tasted the sample and compared to water samples with known salinities \ud83d\ude42<\/li><\/ul>\n\n\n\n<p>The numbers they came up with were as diverse as their approaches so this was also a nice demonstration of the difficulties to accurately measure salinity.<\/p>\n\n\n\n<p>(And of course the salinity of the water sample they got was about 35, but who cares? \u2013 the journey is the reward!)<\/p>\n\n\n\n<p><em>P.S.: This is a repost, first published <\/em><a href=\"https:\/\/mirjamglessmer.com\/2015\/06\/29\/guest-post-estimating-salinity-as-a-homework-assignment\/\"><em>here<\/em><\/a><em> (29.6.2015)<\/em><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Today we are looking back at a homework assignment that&nbsp;Joke L\u00fcbbecke gave her students 5 years ago, but that\u2019s still interesting &amp; relevant and also a lot of fun! The task is easy: \u201cestimate salinity of this water sample!\u201d. But how do you do that? Here are three different ways to solve the problem Estimating [&hellip;]<\/p>\n","protected":false},"author":92,"featured_media":131,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[7],"tags":[],"class_list":["post-130","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-teaching"],"_links":{"self":[{"href":"https:\/\/www.oceanblogs.org\/teachingoceanscience\/wp-json\/wp\/v2\/posts\/130","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.oceanblogs.org\/teachingoceanscience\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.oceanblogs.org\/teachingoceanscience\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.oceanblogs.org\/teachingoceanscience\/wp-json\/wp\/v2\/users\/92"}],"replies":[{"embeddable":true,"href":"https:\/\/www.oceanblogs.org\/teachingoceanscience\/wp-json\/wp\/v2\/comments?post=130"}],"version-history":[{"count":3,"href":"https:\/\/www.oceanblogs.org\/teachingoceanscience\/wp-json\/wp\/v2\/posts\/130\/revisions"}],"predecessor-version":[{"id":136,"href":"https:\/\/www.oceanblogs.org\/teachingoceanscience\/wp-json\/wp\/v2\/posts\/130\/revisions\/136"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.oceanblogs.org\/teachingoceanscience\/wp-json\/wp\/v2\/media\/131"}],"wp:attachment":[{"href":"https:\/\/www.oceanblogs.org\/teachingoceanscience\/wp-json\/wp\/v2\/media?parent=130"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.oceanblogs.org\/teachingoceanscience\/wp-json\/wp\/v2\/categories?post=130"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.oceanblogs.org\/teachingoceanscience\/wp-json\/wp\/v2\/tags?post=130"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}