<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-645" name="Wave-driven Current" parent="WC-627" scope="Hydroform: Residual current caused by asymmetrical force created by wave motion."/><bt><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><nt><term thcode="62" code="WC-667" name="Longshore Current" parent="WC-645" scope="Hydroform Type: A current that moves parallel to or at an oblique angle to the shoreline, carrying water and often transporting soft sediments downstream. ..."/><term thcode="62" code="WC-668" name="Rip Current" parent="WC-645" scope="Hydroform Type: A formation of water flow in a seaward direction generated by wave action and local topography nearshore. ..."/><term thcode="62" code="WC-669" name="Undertow" parent="WC-645" scope="Hydroform Type: Seaward-directed current generated by water that is receding from the shoreline after wave run up."/></nt></descriptor>