<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-666" name="Semi-diurnal Tidal Flow" parent="WC-643" scope="Hydroform Type: Tidal ocean waters where the gravitational action of the sun and moon on Earth's oceans create two high and two low tides per day of relatively equal amplitude."/><bt><term thcode="62" code="WC-643" name="Tidal Flow" parent="WC-627" scope="Hydroform: Advective flow resulting from of tidal movement, often amplified in velocity when moving through an inlet, pass or channel. ..."/><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>