<descriptor thcode="61"><thesaurus thcode="61" name="Marine Realms Information Bank (MRIB) keywords" scope="Theme keywords from the former Marine Realms Information Bank, focusing on characteristics of coasts and oceans, processes acting on them, and human concerns about them." creator="U.S. Geological Survey" rights="Public domain" date="2016-09-07" codetype="number" prefix="mrib" tblname="mrib" nonpref="mribnp" relterm="mribrt" root_code="1" contact="aallwardt"><category><term thcode="25" code="27" name="types" parent="26" scope="Terms are types of things rather than named instances"/><term thcode="25" code="16" name="hierarchical" parent="11" scope="Substantive broader-narrower relationships exist among the terms."/><term thcode="25" code="13" name="transitive" parent="12" scope="Narrower terms have an &quot;is a&quot; relationship with their broader terms, and generally can be described as part-of, type-of, or instance-of the broader term."/><term thcode="25" code="5" name="theme" parent="2" scope="Terms indicate domains of human concern, such as scientific discipline, societal problems, or characteristics of earth, space, oceans, and living things."/><term thcode="25" code="21" name="disciplines" parent="2" scope="Broad categories of human inquiry or activity, such as scientific disciplines."/><term thcode="25" code="20" name="methods" parent="2" scope="Actions taken to obtain or analyze information"/><term thcode="25" code="27" name="types" parent="26" scope="Terms are types of things rather than named instances"/><term thcode="25" code="16" name="hierarchical" parent="11" scope="Substantive broader-narrower relationships exist among the terms."/><term thcode="25" code="13" name="transitive" parent="12" scope="Narrower terms have an &quot;is a&quot; relationship with their broader terms, and generally can be described as part-of, type-of, or instance-of the broader term."/><term thcode="25" code="5" name="theme" parent="2" scope="Terms indicate domains of human concern, such as scientific discipline, societal problems, or characteristics of earth, space, oceans, and living things."/><term thcode="25" code="21" name="disciplines" parent="2" scope="Broad categories of human inquiry or activity, such as scientific disciplines."/><term thcode="25" code="20" name="methods" parent="2" scope="Actions taken to obtain or analyze information"/></category><altlabel><altlabel>MRIB keywords</altlabel><altlabel>MRIB keywords</altlabel><altlabel>Marine Realms Information Bank keywords</altlabel><altlabel>Marine Realms Information Bank keywords</altlabel></altlabel></thesaurus><term thcode="61" code="402" name="multibeam echo sounder" parent="401" scope="acoustic technique for determining sea-floor depths in a wide swath centered below the instrument platform."/><uf><usefor name="multi-beam echo sounder"/><usefor name="multi-beam echosounder"/><usefor name="multi-beam sonar"/><usefor name="multibeam echosounder"/><usefor name="multibeam sonar"/></uf><bt><term thcode="61" code="401" name="acoustic methods" parent="400" scope=" measurement of sound propagation in a given medium (such as water) for ranging or acoustical studies."/><term thcode="61" code="400" name="field observation" parent="398" scope="scientific investigation of physical or biological features and processes in a natural setting."/><term thcode="61" code="398" name="research method" parent="1"/><term thcode="61" code="1" name="Marine Realms Information Bank (MRIB) keyword categories"/></bt><rt><term thcode="61" code="719" name="marine geology" parent="711" scope="used for geological and related studies of ocean basins and margins."/><term thcode="61" code="738" name="marine geophysics" parent="734" scope="used for geophysical and related studies of ocean basins and margins."/></rt></descriptor>