<descriptor thcode="62"><thesaurus thcode="62" name="Coastal and Marine Ecological Classification Standard" scope="Categories of ecosystems for coastal, estuarine, and marine environments." creator="FGDC" rights="public domain" date="2017-05-10" codetype="alpha" prefix="cmecs" uri="https://www2.usgs.gov/science/CMECS" tblname="cmecs" root_code="root" contact="pschweitzer"><category><term thcode="25" code="16" name="hierarchical" parent="11" scope="Substantive broader-narrower relationships exist among the terms."/><term thcode="25" code="16" name="hierarchical" parent="11" scope="Substantive broader-narrower relationships exist among the terms."/></category><altlabel><altlabel>CMECS</altlabel><altlabel>CMECS</altlabel><altlabel>Coastal and Marine Ecological Classification Standard (CMECS)</altlabel><altlabel>Coastal and Marine Ecological Classification Standard (CMECS)</altlabel></altlabel></thesaurus><term thcode="62" code="WC-651" name="Abyssal Deep Circulation" parent="WC-632" scope="Hydroform Type: Deep, slow circulation in the abyssal zone driven by horizontal differences in density of water masses. ..."/><bt><term thcode="62" code="WC-632" name="Deep Circulation" parent="WC-627" scope="Hydroform: The mass circulation of the oceans that carries cold polar surface water to depth, sinking due to higher density and wind forcing. ..."/><term thcode="62" code="WC-627" name="Current" parent="WC-C012" scope="Hydroform Class: Water that is undergoing coherent mass movement, either as laminar or turbulent flow, relative to surrounding waters and fixed structural, landform or geologic features. ..."/><term thcode="62" code="WC-C012" name="Hydroform" parent="WC-C001"/><term thcode="62" code="WC-C001" name="Water Column" parent="root"/><term thcode="62" code="root" name="CMECS" scope="Coastal and Marine Ecological Classification Standard: Category terms encompassing waters from the head of tide or inland incursion of ocean salinity to the splash zone of the coasts to the deepest portions of the oceans and the deep waters of the Great Lakes."/></bt></descriptor>