Earth System Science Vocabularies Part I:
General Science Topics, Processes and Concepts

States of Matter

Forms of matter as solid, liquid or vapor, differing in their observable physical properties

Processes that Alter States of Matter

Process by which a vapor becomes liquid or solid
chemical fractionation
Compositional differentiation via numerous chemical processes
phase transformations
Change of a crystal from one polymorph to another
Transformation from a solid to a liquid state
Transformation from a liquid or vapor to a solid state
A (metamorphic) reaction that results in the transfer of H2O to the fluid phase
Mineralogical, chemical and textural adjustment of solid rocks to physical and chemical conditions
Physical disintegration or chemical decomposition of rock
A homogeneous mixture of two or more components in a single phase, often refers specifically to a solution in water (an aqueous solution); a process of chemical weathering by which rock and mineral material passes into solution
The formation of an insoluble solid by a reaction which occurs in solution

Chemistry: topics and concepts

inorganic chemistry
Study of compounds that contain no carbon
Study of crystals, their growth, structure, and physical properties
analytical chemistry
Characterization of the composition, structure and properties of materials
organic chemistry
The study of carbon-containing compounds, typically containing carbon-carbon bonds
The study of the chemistry of living systems
physical chemistry
Encompassing thermodynamics, quantum chemistry, and chemical kinetics
A set of laws that predicts the equilibrium configuration of a system and how it will change if its environmental parameters are changed
A measure of the extent to which the energy of a system is available for conversion to work
H=E + PV (E=internal energy of a system and PV are pressure and volume respectively); -of a reaction is the heat evolved or absorbed in a reaction at constant pressure
intensive parameter
A property that is independent of the amount of a material, e.g. density
extensive parameter
A property that is dependent of the amount of material, e.g. mass or volume
A measure of force exerted on a unit area
The condition of a body that determines the transfer of heat to or from another body
First Law of Thermodynamics
A statement of the conservation of energy; heat absorbed by a system must either raise the internal energy of the system or do work on the environment
Second Law of Thermodynamics
Heat can never pass spontaneously from a body at a lower temperature to one at a higher temperature
Gibbs free energy
A function of state that is reversible during a reversible isobaric-isothermal reaction
heat capacity
Quantity of heat needed to raise one unit mass of a substance one degree Celsius
Measurement of thermal constants of a substance
activity or fugacity
Thermodynamic partial pressure of a component; the ideal thermodynamic concentration of a substance which permits the application of the law of mass action
phase equilibria
Chemical reactions among multiple phases
exothermic reactions
Chemical reactions that liberate heat
endothermic reactions
Chemical reactions that consume heat
adiabatic reactions
A process that occurs without gain or loss of heat to or from the system
reversible reactions
A reaction that can be forced to occur in either direction by variation of pressure, temperature, volume or quantity of reacting substances
irreversible reactions
A reaction that takes place in one direction only, and therefore proceeds to completion
The study of rates at which chemical reactions proceed
statistical mechanics
Theoretical predictions of the behavior of a microscopic system based on application of statistical laws to the behavior of component particles

Physics: topics and concepts

Mechanical Transfer of Heat and Mass

Transfer of heat in a fluid by the circulation flow due to temperature differences (resulting in density differences)
Transfer of heat controlled by thermal conductivity of materials, related to heat flux and temperature gradient
Heat Source
radioactive decay
Spontaneous emission of particles (alpha or beta) or gamma rays from the unstable nucleus of a nuclide; results in the generation of heat
kinetic energy/friction
Energy arising from motion; resistance to motion

Electro-Magnetic Properties

magnetic field
Forces related to magnetic poles; associated with electric currents and the motions of electrons in atoms
electrical conductivity
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; reciprocal of resistivity


Process whereby small particles and gases in the solar nebula come together to form larger bodies, eventually of planetary size
A collision of two planetary bodies at or near cosmic velocity
Change in the direction of axis of rotation; westward motion of the equinoxes caused mainly by the gravitational attraction of the sun and moon on the equatorial bulge of the earth
Kepler's laws of planetary motion
1. The planets describe ellipses with the sun at a focus. 2. The line from the sun to any planet describes equal areas in equal times. 3. The squares of the periodic times of the planets are proportional to the cubes of their mean distances from the sun.
Rhythmic, alternate rise and fall of a surface (water, land) resulting from gravitational attraction
isostasy (bouyancy)
Condition of equilibrium, similar to floating, of the components of the lithosphere above the aesthenosphere


Study of the way in which velocities and accelerations of various parts of a moving system are related
A dynamical quantity, conserved in a closed system, defined as the product of mass and velocity; linear and angular momentum
oscillation (vibration)
Any motion that repeats itself in equal intervals of time; periodic motion.
Uniform movement in one dimension, without rotation
Circular turning of a body about an axis
rigid body dynamics
Deforming (solid) body suffers no distortion, dilation or rotation
fluid dynamics
Study of motion in fluids

Dynamic Properties and Processes

Property of a substance to offer internal resistance to flow
Study of the deformation and flow of mater
Flow of material from regions of high to low concentration; proportional to concentration gradient
Flow of a fluid into a solid substance; driven by pressure gradient
Principle of Relativity
The observed value of the velocity of light is constant and is independent of the motion (frame of reference) of the observer


Particle motion is perpendicular to the direction of propagation of the wave (S or shear wave)
Particle motion is in the direction of propagation of the wave (P or primary wave, compressional)
A water wave, the form of which oscillates vertically between two nodes without progressive movement
Acoustic waves, longitudinal motion; compressional
Deflection of a wave due to its passage from one medium to another of differing density; changes the velocity
The return of a wave incident upon a surface to its original medium
Phenomena observed when waves are obstructed by obstacles or apertures, the disturbance spreads beyond the limits of the geometrical shadow of the object.
Irregular reflection or dispersal of waves or particles
Interaction between two or more waves
The study of light and its wave properties

Quantum Mechanics

quantum theory
electromagnetic radiation is emitted and adsorbed in discrete quanta, each of magnitude hv where h is Planck's constant and v is the frequency of the radiation; encompasses black body radiation, photoelectric effect, Compton effect and Bohr theory of the atom
Schrodinger equation
fundamental equation of wave mechanics; expresses the probability density for a particle or set of particles.
uncertainty principle
There is a fundamental limit to the precision with which a position coordinate of a particle and its momentum in that direction can be simultaneously known

Biology: topics and concepts

cellular biology
Study of life at the cellular level
Study of plant life forms
Study of animal life forms
The study of the interrelations between living organisms and their environment, including both the physical and biotic factors.
Study of heredity, how differences between individuals are transmitted from one generation to the next, and how the information in the genes is used in the development of functioning of the adult organism.
Study of the form and function of plants and animals. Physiology - the study of the relation between structure and function.
Classification applied to living organisms
Changes in the genetic composition of a population during successive generations; the gradual development of more complex organisms from simpler ones
Any morphological, physiological or behavioural characteristic which fits an organism to the conditions under which it lives; the genetic or developmental processes by which such characteristics arise
adaptive radiation
Evolutionary diversification of species from a common ancestral stock, filling available ecological niches
A change, spontaneous or induced, that converts one allele into another; any change of a gene or of chromosomal structure or number
natural selection
Evolutionary theory which postulates the survival of the best adapted forms, with inheritance of those characteristics wherein their fitness lies, and which arise as random variations due to mutation

Mathematics: topics, concepts and skills


Science of numbers, including processes such as addition, subtraction, multiplication, division and the extraction of roots
Investigation of the properties of number by means of symbols; solving of equations, summation of series, permutations and combinations, matrices, and sets
Concerned with the properties of lines, curves and surfaces; divided into pure, algebraic and differential geometry
Relations among the sides and angles of triangles
differential calculus
Dealing with continuously varying quantities; based on the derivative of one quantity with respect to another of which it is a function (inverse of integral calculus).
integral calculus
Purpose is to find the value of a function of a variable when its derivative is known; integration is used in the solution of such problems as finding the area enclosed by a given curve. (inverse of differential calculus)
The generalization of a vector; a mathematical entity specifiable by a set of components with respect to a system of coordinates
non-linear systems
Mathematical representation of which the result of an action is not necessarily proportional to its cause
Encompasses principles related to e.g., self-organization, sensitive dependence on initial conditions, strange attractors
A shape made of parts similar to the whole in some way; includes concepts of fractal dimensions, similarity and scaling

Quantitative Skills

To determine by mathematical means; calculate.
To judge approximately; to determine roughly the size, extent or nature.
Including e.g. units of measure, dimensions, orders of magnitude
Amount, degree, dimensions, capacity of something as determined by comparison to a standard
error and uncertainty
Difference between measured and actual values; and indefinite, indeterminate
Mathematical basis of a prediction; ratio of the outcomes that could produce an event to the total number of possible outcomes
Numerical quantity calculated from a set of observations
A diagram that represents the variation of a variable in comparison with that of one or more other variables
Systematic arrangement of data in rows and columns
A group of numerical symbols associated to express a single concept or principle
A diagrammatic representation.
A description or analogy used to help visualize something that cannot be directly observed; a system of postulates, data, and inferences presented as a mathematical description of an entity
equations as language
Using equations to describe natural phenomena