{"id":202,"date":"2017-03-01T21:01:20","date_gmt":"2017-03-01T21:01:20","guid":{"rendered":"https:\/\/pressbooks.ccconline.org\/introduction-to-oceanography\/chapter\/5-7-classifying-elements-in-seawater\/"},"modified":"2021-10-25T18:20:01","modified_gmt":"2021-10-25T18:20:01","slug":"5-7-classifying-elements-in-seawater","status":"publish","type":"chapter","link":"https:\/\/pressbooks.ccconline.org\/introduction-to-oceanography\/chapter\/5-7-classifying-elements-in-seawater\/","title":{"raw":"5.7 Classifying Elements in Seawater","rendered":"5.7 Classifying Elements in Seawater"},"content":{"raw":"Now that we are familiar with the abundance and profiles of some common dissolved substances in the ocean, we can try to classify these materials based on their distribution. Dissolved materials are usually classified into one of several groups:\n\n<strong>Conservative Elements<\/strong> are those whose concentration is relatively constant across the ocean, both vertically and horizontally. This category would include the major ions in seawater, such as sodium or chloride, which have very long residence times and whose concentration only changes through the addition or removal of fresh water (see <a href=\"\/chapter\/5-3-salinity-patterns\/\">section 5.3<\/a>).\n\n<strong>Nutrient-like Elements<\/strong> have a distribution similar to the profile we described for nitrate in the previous section. Concentrations of these substances are low at the surface, as they are rapidly used up by biological processes. Below the [pb_glossary id=\"728\"]photic zone[\/pb_glossary], concentrations of these materials will increase, as decomposition by bacteria cycles them back into the water column.\n\n<strong>Scavenged Elements<\/strong> are those that react with other particles and are adsorbed to the particle surface. When the particles sink, those elements are removed to the [pb_glossary id=\"1126\"]sediment[\/pb_glossary]. Scavenged profiles generally show higher abundance at the surface, where the materials will enter the ocean, but declining levels with depth as they are removed by the sinking particles. This profile is common for metals, such as aluminum or lead.\n\n<strong>Stable Gases<\/strong> dissolve into the ocean from the atmosphere. Because these substances are not very reactive, the ocean water becomes saturated with these gases. Since [pb_glossary id=\"1156\"]solubility [\/pb_glossary] of a gas increases in colder water, these gases are often found in greater concentrations in deep, cold water, and in lower concentrations in warmer surface water.\n\n<hr>\n\n<div class=\"textbox textbox--key-takeaways\"><header class=\"textbox__header\">\n<p class=\"textbox__title\">Additional links for more information<\/p>\n\n<\/header>\n<div class=\"textbox__content\">\n<ul>\n \t<li>Interactive periodic table of the elements, where you can click on any element to see its vertical profile in the ocean: <a href=\"https:\/\/www.mbari.org\/science\/upper-ocean-systems\/chemical-sensor-group\/periodic-table-of-elements-in-the-ocean\/\" target=\"_blank\" rel=\"noopener noreferrer\">https:\/\/www.mbari.org\/science\/upper-ocean-systems\/chemical-sensor-group\/periodic-table-of-elements-in-the-ocean\/<\/a><\/li>\n<\/ul>\n<\/div>\n<\/div>\n&nbsp;","rendered":"<p>Now that we are familiar with the abundance and profiles of some common dissolved substances in the ocean, we can try to classify these materials based on their distribution. Dissolved materials are usually classified into one of several groups:<\/p>\n<p><strong>Conservative Elements<\/strong> are those whose concentration is relatively constant across the ocean, both vertically and horizontally. This category would include the major ions in seawater, such as sodium or chloride, which have very long residence times and whose concentration only changes through the addition or removal of fresh water (see <a href=\"\/chapter\/5-3-salinity-patterns\/\">section 5.3<\/a>).<\/p>\n<p><strong>Nutrient-like Elements<\/strong> have a distribution similar to the profile we described for nitrate in the previous section. Concentrations of these substances are low at the surface, as they are rapidly used up by biological processes. Below the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_202_728\">photic zone<\/a>, concentrations of these materials will increase, as decomposition by bacteria cycles them back into the water column.<\/p>\n<p><strong>Scavenged Elements<\/strong> are those that react with other particles and are adsorbed to the particle surface. When the particles sink, those elements are removed to the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_202_1126\">sediment<\/a>. Scavenged profiles generally show higher abundance at the surface, where the materials will enter the ocean, but declining levels with depth as they are removed by the sinking particles. This profile is common for metals, such as aluminum or lead.<\/p>\n<p><strong>Stable Gases<\/strong> dissolve into the ocean from the atmosphere. Because these substances are not very reactive, the ocean water becomes saturated with these gases. Since <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_202_1156\">solubility <\/a> of a gas increases in colder water, these gases are often found in greater concentrations in deep, cold water, and in lower concentrations in warmer surface water.<\/p>\n<hr \/>\n<div class=\"textbox textbox--key-takeaways\">\n<header class=\"textbox__header\">\n<p class=\"textbox__title\">Additional links for more information<\/p>\n<\/header>\n<div class=\"textbox__content\">\n<ul>\n<li>Interactive periodic table of the elements, where you can click on any element to see its vertical profile in the ocean: <a href=\"https:\/\/www.mbari.org\/science\/upper-ocean-systems\/chemical-sensor-group\/periodic-table-of-elements-in-the-ocean\/\" target=\"_blank\" rel=\"noopener noreferrer\">https:\/\/www.mbari.org\/science\/upper-ocean-systems\/chemical-sensor-group\/periodic-table-of-elements-in-the-ocean\/<\/a><\/li>\n<\/ul>\n<\/div>\n<\/div>\n<p>&nbsp;<\/p>\n<div class=\"glossary\"><span class=\"screen-reader-text\" id=\"definition\">definition<\/span><template id=\"term_202_728\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_202_728\"><div tabindex=\"-1\"><p>the upper regions of the ocean where there is enough light to support photosynthesis; approximately 0-200 m; also called the euphotic zone (1.2)<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_202_1126\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_202_1126\"><div tabindex=\"-1\"><p>unconsolidated particles of mineral or rock that settle to the seafloor (12.1)<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_202_1156\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_202_1156\"><div tabindex=\"-1\"><p>the amount of a dissolved substance that water can hold under a particular set of conditions, which are usually defined as 0 degrees C and 1 atmosphere of pressure (5.4)<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><\/div>","protected":false},"author":33,"menu_order":8,"template":"","meta":{"pb_show_title":"on","pb_short_title":"","pb_subtitle":"","pb_authors":["paul-webb"],"pb_section_license":"cc-by"},"chapter-type":[],"contributor":[60],"license":[52],"class_list":["post-202","chapter","type-chapter","status-publish","hentry","contributor-paul-webb","license-cc-by"],"part":160,"_links":{"self":[{"href":"https:\/\/pressbooks.ccconline.org\/introduction-to-oceanography\/wp-json\/pressbooks\/v2\/chapters\/202","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/pressbooks.ccconline.org\/introduction-to-oceanography\/wp-json\/pressbooks\/v2\/chapters"}],"about":[{"href":"https:\/\/pressbooks.ccconline.org\/introduction-to-oceanography\/wp-json\/wp\/v2\/types\/chapter"}],"author":[{"embeddable":true,"href":"https:\/\/pressbooks.ccconline.org\/introduction-to-oceanography\/wp-json\/wp\/v2\/users\/33"}],"version-history":[{"count":2,"href":"https:\/\/pressbooks.ccconline.org\/introduction-to-oceanography\/wp-json\/pressbooks\/v2\/chapters\/202\/revisions"}],"predecessor-version":[{"id":1316,"href":"https:\/\/pressbooks.ccconline.org\/introduction-to-oceanography\/wp-json\/pressbooks\/v2\/chapters\/202\/revisions\/1316"}],"part":[{"href":"https:\/\/pressbooks.ccconline.org\/introduction-to-oceanography\/wp-json\/pressbooks\/v2\/parts\/160"}],"metadata":[{"href":"https:\/\/pressbooks.ccconline.org\/introduction-to-oceanography\/wp-json\/pressbooks\/v2\/chapters\/202\/metadata\/"}],"wp:attachment":[{"href":"https:\/\/pressbooks.ccconline.org\/introduction-to-oceanography\/wp-json\/wp\/v2\/media?parent=202"}],"wp:term":[{"taxonomy":"chapter-type","embeddable":true,"href":"https:\/\/pressbooks.ccconline.org\/introduction-to-oceanography\/wp-json\/pressbooks\/v2\/chapter-type?post=202"},{"taxonomy":"contributor","embeddable":true,"href":"https:\/\/pressbooks.ccconline.org\/introduction-to-oceanography\/wp-json\/wp\/v2\/contributor?post=202"},{"taxonomy":"license","embeddable":true,"href":"https:\/\/pressbooks.ccconline.org\/introduction-to-oceanography\/wp-json\/wp\/v2\/license?post=202"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}