Earth System Science Vocabularies Part V:
Knowing About the Earth
The science of collecting,
processing, and interpreting images that record the interaction between
electro-magnetic energy and matter. Acquiring information about an object
or phenomenon by a recording device that is not in physical contact with
the subject being studied; e.g. aerial photography and imagery acquired
from satellites. Including
airborne imaging, aerial photography, LIDAR, side-looking airborne radar,
satellite imaging (infrared, AVHRR), microwave imaging, radar imaging,
visible light imaging.
A map on
which is recorded geologic information such as the distribution, nature,
and age relationships of rock units, surficial deposits and the occurrence
of structural features, mineral deposits and fossil localities.
Selection of a subset of
a population that, if properly selected, may be used to estimate the parameters
of the population (e.g. geochemical sampling)
including in situ monitoring, telemetry, networks, video monitoring, acquisition of images
and photographs, weather monitoring
temperature, electrical resistivity, gamma-ray measurements
including altimetry, bathymetry, land surveying, global positioning
A region in which magnetic
forces would be exerted on any magnetized bodies or electric currents
present; the region of influence of a magnetized. body or an electric
A measure of the ease with
which a conduction current can be caused to flow through a material under
the influence of an applied electric field.
The electrical resistance per unit length of a unit cross-sectional
area of a material.
A region associated with
any mass distribution that gives rise to forces of gravitational attraction.
Measurement of the amount
of heat leaving the Earth. It involves measuring the geothermal gradient
of rocks by accurate resistance thermometers in drill holes, and the thermal
conductivity of rocks. Term
used for subdisciplines of geophysics concerned with the measurement,
reduction and interpretation of conductive heat flow through the Earth's
The rate of change of temperature
in the Earth with depth. The gradient differs from place to place depending
on the heat flow in the region and the thermal conductivity of the rocks.
The study of earthquakes, and of the structure of the Earth, by
both natural and artificially generated seismic waves.
The return of a wave incident upon a surface to its original medium.
The deflection of an energy
wave due to its passage from one medium to another of differing density,
which changes its velocity.
A method for finding the
velocity distribution from a multitude of observations using combinations
of source and receiver locations.
The figure of the Earth considered
as a sea-level surface extended continuously through the continents. It
is a theoretically continuous surface that is perpendicular at every point
to the direction of gravity. It is the surface of reference for astronomical
observations and for geodetic leveling.
A modulus of elasticity which
relates a change in volume to a change in hydrostatic state of stress;
it is the reciprocal of compressibility.
The ratio of the lateral
unit strain to the longitudinal unit strain in a body that has been stressed
longitudinally within its elastic limit.
The study of the deformation
and flow of matter.
The change in shape or volume
of a body as a result of stress.
In physical chemistry, the
study of those phases, which under specified conditions, may exist in
equation of state
An equation interrelating
the thermodynamic variables that define the state of a system. It is classically
applied to simple gases and liquids in terms of pressure, volume and temperature,
but in modern geochemistry and petrology it is commonly extended to solids
and to solutions.
cell culture experiment
growth of life forms (e.g.
microbes) in experimental culture media.
chemical analysis (bulk samples)
Including atomic absorption,
chromatography, mass spectroscopy, neutron activation analysis, particle
beam analysis (electron microprobe, energy dispersive spectrometry)
chemical analysis (material surfaces)
Including Auger Electron
Spectroscopy, X-ray photoelectron spectroscopy, secondary ion mass spectrometry
(dynamic and time-of-flight)
as indicators of paleoclimate, geothermometers
isotopic analysis-radioactive elements
for radiometric age determination
and as petrogenetic indicators
including optical microscopy
(petrography), electron microscopy (scanning and transmission electron microscopy) and nanoscale analysis using scanning tunneling
and variants of atomic force microscopy.
including Curie temperature
analysis, hysteresis, laboratory-induced magnetization analysis, magnetic
susceptibility analysis, and natural remnant magnetism analysis.
A computer program and associated
data bases that permit cartographic information to be queried by geographic
coordinates of features. Usually the data are organized in layers representing
different geographic entities such as hydrology, culture, topography,
etc. allowing information from different layers to be easily integrated
A working hypothesis or precise
simulation by means of description, statistical data, or analogy, of a
phenomenon or process that cannot be observed directly or that is difficult
to observe directly. Models may be derived by various methods, e.g. by
computer, or by scaled experiments; computational models, physical models,
theoretical models. May produce
visualizations or simulations.
Including image analysis,
mathematical modeling, statistical analysis, visualization methods
An explanatory system of
propositions, general principles or laws, inferred from the phenomena
and linking known facts and observations; held to be true until contradicted
or amended by new facts or observations (e.g. theory of evolution, plate
tectonics, quantum mechanics).