<descriptor thcode="2"><thesaurus thcode="2" name="USGS Thesaurus" scope="Topics and methods of scientific study carried out by USGS, with product types, scientific disciplines, geologic time, and types of institutional structure and activities.  Broad and shallow, used to help people find scientific information." creator="U.S. Geological Survey" rights="Public domain" edition="2.0" date="2020-01-09" codetype="number" prefix="topic" uri="https://www2.usgs.gov/science/USGSThesaurus" tblname="term" nonpref="nonpref" relterm="relterm" root_code="1" contact="pschweitzer"><category><term thcode="25" code="29" name="distinct labels" parent="26" scope="Preferred labels (descriptor texts) are distinct within the thesaurus. A concept can be specified either by its unique identifier (code) or by the text of its descriptor."/><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="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="19" name="organizational functions" parent="2" scope="Things that organizations do, typically including various types of programs, projects, and services."/><term thcode="25" code="7" name="temporal" parent="2" scope="Terms indicate periods of time, such as chronostratigraphic units, named historical periods or intervals surrounding known historical events, or seasons."/><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="29" name="distinct labels" parent="26" scope="Preferred labels (descriptor texts) are distinct within the thesaurus. A concept can be specified either by its unique identifier (code) or by the text of its descriptor."/><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="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="19" name="organizational functions" parent="2" scope="Things that organizations do, typically including various types of programs, projects, and services."/><term thcode="25" code="7" name="temporal" parent="2" scope="Terms indicate periods of time, such as chronostratigraphic units, named historical periods or intervals surrounding known historical events, or seasons."/><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."/></category><altlabel><altlabel>USGSThesaurus</altlabel><altlabel>USGSThesaurus</altlabel></altlabel></thesaurus><term thcode="2" code="1147" name="tectonophysics" parent="470" scope="Branch of geophysics concerned with the structural forces affecting the deformation, uplift, and movement of the earth's crust."/><bt><term thcode="2" code="470" name="geophysics" parent="291" scope="Branch of geology studying the physical characteristics and phenomena of the earth and its atmosphere."/><term thcode="2" code="291" name="earth sciences" parent="1019" scope="Broad term for all science related to the study of the earth."/><term thcode="2" code="1019" name="sciences" parent="1" scope="Major educational fields, fields of study, and professional groupings within USGS."/><term thcode="2" code="1" name="Categories" scope="Thematic terms for categorizing information resources.  This thesaurus is intended to support finding and understanding scientific information."/></bt><rt><term thcode="2" code="61" name="asthenosphere" parent="690" scope="A layer of the earth within the upper mantle and directly below the lithosphere. This layer has a semi-solid consistency that reaches to about 200 kilometers (124 miles) below the surface."/><term thcode="2" code="199" name="continental lithosphere" parent="667" scope="The earth's hard, outermost shell comprised of the crust and the upper part of the mantle."/><term thcode="2" code="219" name="crust (earth)" parent="292" scope="The outermost layer of the earth which is relatively thin, of lower density than the core, and rocky."/><term thcode="2" code="288" name="earth history" parent="455" scope="The structural and compositional changes that the earth has undergone from its formation. Use for discussions of the whole earth (or large sections of it) instead of regional studies."/><term thcode="2" code="292" name="earth structure" parent="287" scope="Major interior structural features of the planet earth."/><term thcode="2" code="304" name="earthquakes" parent="451" scope="Ground shaking caused by the sudden release of accumulated strain by an abrupt shift of rock along a fracture in the earth or by volcanic or magmatic activity, or other sudden stress changes in the earth."/><term thcode="2" code="667" name="lithosphere" parent="219" scope="The solid outer zone of the earth comprising the crust and the upper layer of the mantle."/><term thcode="2" code="781" name="neotectonic processes" parent="1145" scope="Changes which took place during geological time after the Miocene era and are associated with the structural forces that affect the deformation, uplift, and movement occurring in the earth's crust."/><term thcode="2" code="824" name="oceanic lithosphere" parent="667" scope="The solid outer zone of the earth, covered by seawater, and comprised of the crust and the upper layer of the mantle."/><term thcode="2" code="1117" name="structural geology" parent="464" scope="Branch of geology concerned with the distribution, position, shape, and internal structure of rocks."/><term thcode="2" code="1145" name="tectonic processes" parent="451" scope="The structural forces affecting the deformation, uplift, and movement of the earth's crust."/><term thcode="2" code="1289" name="volcanology" parent="464" scope="The branch of geology that deals with volcanism and the processes involved in magma flow and eruption through a vent in the earth's surface."/></rt></descriptor>