The Digital Library for Earth System Education (DLESE) community has asked for the ability to search/browse in ways that support Earth system science education. The Earth system approach emphasizes the processes and linkages in the Earth system across the traditional sub-disciplines in the Earth sciences, including connections to the biosphere and to humanity (AGU, 1997). To begin this process, it is necessary to develop "controlled vocabularies" which are then used to formulate the metadata needed to appropriately characterize a given resource. A small ad hoc group has prepared an initial matrix of terms that we hope will be useful in describing the totality of the Earth system, and will support the anticipated ways in which users will want to access resources. These vocabularies derive from an array of existing Earth system texts, glossaries, indexes, and atlases.
The following principles guided the development of these vocabularies:
- The vocabularies have been developed to enable discovery of Earth system information through search and browse capabilities. These terms have been selected to anticipate the many ways in which instructors and students of the Earth are expected to seek information about the Earth.
- The number of terms used in any category must be limited to a reasonable number (ca. 30-50). This relates to the so-called "granularity" issue;the terms must be specific enough to enable discovery by the users, but not so overwhelming in number that the system is rendered ineffective. So, this is not meant to be a comprehensive compilation of all terms pertaining to the Earth (e.g. AGI and AMS glossaries). Rather, the terms are meant to be guideposts to assist users in their quest for useful information primarily to support Earth system education, but hopefully all Earth scientists and citizens-at-large will find this system useful as well.
- An attempt was made to develop a "flat" structure, i.e. that the terms are roughly on the same taxonomic level. However, a strict adherence to hierarchies of information or taxonomies was not always followed because certain terms have earned prominence through common usage (i.e. these are terms that are likely to be searched for by any number of users).
- These vocabularies should serve to make connections within the Earth science disciplines, and by extension, to our sister disciplines in the physical, life and social sciences and engineering disciplines (e.g. through the National Science, Technology, Engineering, and Mathematics [STEM] Education Digital Library, NSDL; http://nsdl.org).
- These vocabularies should support a) creators and catalogers of instructional resources, to best characterize these resources for future discovery, and b) all users of the library who seek specific resources among the many dimensions of Earth system science (i.e. users in all learning environments, at all levels of instruction and interest).
We have identified 6 dimensions that we anticipate will support discovery about the Earth system science:
Part I: General Science Topics, Processes and Concepts-these are fundamental scientific and mathematical principles that are common to all the STEM disciplines. These concepts will help us to link to digital libraries in sister disciplines through the NSDL. However, the terms chosen for this list are those that have particular significance in the context of Earth system science.
Part II: Earth System Processes-covering all parts of the Earth system, from micro to planetary scales.
Part III: Earth System Environments (Where in the world are you?)-a vertical transect from the core of the Earth to the outermost atmosphere, and covering the surface of the Earth as physiographic, climatological, biome, and cultural domains. (Geospatial referencing, e.g. latitudinal and longitudinal coordinates, and a place name Gazetteer, are being covered in other parts of the DLESE discovery system).
Part IV: Time and the Earth System- understanding and measuring temporal relations in the Earth system, and b) major events in the Earth's history (e.g. geologic time scale, orogenic events, mass extinctions).
Part V: Ways of Knowing About the Earth-the techniques and approaches that provide the evidence about how the Earth system operates: observations, measurements, experiments, modeling, analysis, theory.
Part VI: "Hot Topics" In Science, In the News-contemporary and emerging "hot topics" a) in science, showcasing exciting new breakthroughs in scientific discovery, and b) in the news, topics of interest to the general public, e.g. extreme weather, earthquakes, global change?
The relationships between these numerous dimensions of seeking information about the Earth are illustrated below:
The apices of the quadrilateral (in blue) represent scientific First Principles, Earth System Processes, Earth System Environments, and (geologic) Time. The bold letters on the outside represent Ways of Knowing About the Earth and the many ways of observing, measuring and gaining understanding about the Earth and how it works. The green sphere in the center represents the "Hot Topics" of science and in the news, which may contain elements of all the above. Each of the "binary joins" (with red labels) demonstrates how each of these components informs and relates to each other: e.g., all the joins emanating from First Principles demonstrate the universal laws that govern the operation of the Earth system and address the Why? and How? questions. In turn, Earth System Processes, Earth System Environments, and (geologic) Time provide excellent natural examples and applications of these principles. All the joins radiating from Time demonstrate temporal relations and concepts such as rates, fluxes, frequency, duration, and evolution of Earth systems, and the joins radiating from Earth System Environments contain components of geospatial relations (i.e. how are these environments characterized in what physiographic, climatologic or biological regime, and in what social/cultural context?).
Enabling Discovery Through Search/Browse Functions in DLESE
These Earth system science vocabularies are intended to be recommended extensions to the required metadata already in use by DLESE. The required metadata currently supports discovery of resources, primarily according to geoscience topics, resource type, and intended audience www.dlese.org/Metadata. These Earth system science vocabularies should provide additional dimensions to allow an instructor or student to perform advanced searches to meet specific learning goals about the Earth system: e.g., a student could seek information on mass extinction events, and relate these to Earth system processes and changes in Earth system environments; a physics instructor could support a unit on adiabatic processes, and readily find natural examples in thunderstorms or magma chambers; global change can be investigated over many time scales, by accessing multiple lines of observational and analytical evidence, and in the context of anthropogenic impacts. In aggregate, these six dimensions of discovery should provide a comprehensive framework to explore the Earth system from multiple points of view, and by utilizing multiple combinations of these attributes.
This webpage was created and is maintained by David Mogk, Dept. of Earth Sciences, Montana State University, firstname.lastname@example.org
These pages are hosted on the DLESE Community Issues and Groups area of the Science Education Resource Center at Carleton College, dlesecommunity.carleton.edu
Acknowledgements: Conceptualization and creation of early versions of these Earth system science vocabularies was done in collaboration with Ian MacGregor, National Academy of Sciences, and Karon Kelly, DLESE Program Center. Discussions with Cathy Manduca, Martin Ruzek, Stephanie Stockman and with many other colleagues were a great help in the formative stages. This project was supported by the National Science Foundation, NSF award number: NSF 0085600.