CINDER CONE   :   

A conical hill formed by the accumulation of pyroclastic fragments that fall to the ground in an essentially solid condition.

CINDERS   :   

Loose, vesicular volcanic ejecta 4 to 32 millimeters (.16 to 1.28 inches) in diameter.

CIRCUIT   :   

The path followed by an electric current. Electricity must flow in a circuit to do useful work.

CLAST   :   

A fragment of rock that has been transported, either by volcanic or sedimentary processes.

CLATHRATES   :   

A chemical substance consisting of a lattice of one type of molecule trapping and containing a second type of molecule.

COANDA EFFECT   :   

Described by Henri Coanda, a Romanian scientist, in the 1930's. This effect describes the tendency of moving air of fluids to follow the nearby curved or inclined surface.

CO-ENZYMES   :   

Non-protein substances necessary for the function of some enzymes. Essential coenzymes are also known as vitamins.

COEVOLUTION   :   

Simultaneous evolution of two or more species of organisms that interact in significant ways.

COGNITION   :   

Cognition refers to the physical recognition of external stimuli that lead to conscious experiences.

COHORT STUDY   :   

A study in which patients who presently have a certain condition and/or receive a particular treatment are followed over time and compared with another group who are not affected by the condition under investigation.

COLLES   :   

A small hill or knob.

COMA   :   

The tail made of gases and dust particles that surrounds a comet is known as coma. It is made by the vaporization of the nucleus due to which jets of gas and dust are released.

COMET   :   

It is the icy body that contain a solid nucleus made of water and other dark organic compounds orbiting the Sun. As the comets gets closer to the Sun the nucleus vaporizes forming a 'coma'.

COMPENSATION DEPTH   :   

Depth at which light intensity reaches a level at which oxygen evolved from a photosynthesizing organism equals that consumed by its respiration.

COMPENSATION ZONE   :   

The point at which there is just enough light for a plant to survive. At this point all the food produced by photosynthesis is used up by respiration. For aquatic plants, the compensation point is the depth of water at which there is just enough light to sustain life (deeper water = less light = less photosynthesis).

COMPETITIVE EXCLUSION PRINCIPLE   :   

The hypothesis stating that when organisms of different species compete for the same resources in the same habitat, one species will commonly be more successful in this competition and exclude the second from the habitat.

COMPOSITE VOLCANO   :   

A volcano composed of interbedded lava and pyroclastic material commonly with steep slopes.

CONDENSATION   :   

When a substance changes state from a gas to a liquid.

CONDUCTOR   :   

A thing that transmits heat, electricity, light, sound or other form of energy.

CONTINGENT VALUATION   :   

A survey-based economic technique for the valuation of non-market resources, typically ecosystems and environmental areas and services. It involves directly asking people, in a survey, how much they would be willing to pay for specific environmental services. It is called “contingent” valuation, because people are asked to state their willingness to pay, contingent on a specific hypothetical scenario and description of the environmental service.

CONVECTION   :   

Fluid circulation driven by temperature gradients; the transfer of heat by this automatic circulation (see also Educator's Guide to Convection).

CONVERGENCE   :   

The flowing together of air masses.

CORAL BLEACHING   :   

Refers to the loss of color of corals due to stress-induced expulsion of symbiotic, unicellular algae called zooxanthellae that live within their tissues. Stress can be induced by: (1) increased water temperatures (often attributed to global warming), (2) starvation caused by a decline in zooplankton levels as a result of overfishing, (3) solar irradiance (photosynthetically active radiation and ultraviolet band light), (4) changes in water chemistry, (5) silt runoff, or (6) pathogen infections.

CORE   :   

The core is about 7000 km in diameter with a temperature of 6000oC and a pressure of over 3 million atmospheres. The inner core is a lumpy solid iron sphere and the outer core is a thick liquid iron layer.

CORIOLIS FORCE   :   

The apparent force, resulting from the rotation of the Earth, that deflects air or water movement.

CORONA   :   

The upper level of the solar atmosphere, characterized by low densities and high temperatures it is not visible from the Earth except during a total eclipse of the sun or by use of special telescopes called coronagraphs.

CORONAGRAPH   :   

A special telescope which blocks light from the disk of the Sun in order to study the faint solar atmosphere.

COSMIC RAY   :   

Electromagnetic rays of extremely high frequency and energy; cosmic rays usually interact with the atoms of the atmosphere before reaching the surface of the Earth. Some cosmic rays come from outside the solar system while others are emitted from the Sun and pass through holes in the corona.

COVALENT   :   

The chemical bond between atoms.

CRATER   :   

1) A depression formed by the impact of a meteorite. 2) A depression around the orifice of a volcano.

CRATONS   :   

The relatively stable portions of continents composed of shield areas and platform sediments; typically, cratons are bounded by tectonically active regions characterized by uplift, faulting and volcanic activity.

CRETACEOUS PERIOD   :   

A geological term denoting the interval of Earth history beginning around 144 million years ago and ending 66 million years ago. [ more ]

CRETACEOUS-TERTIARY BOUNDARY   :   

A major stratigraphic boundry on Earth marking the end of the Mesozoic Era, best known as the age of the dinosaurs. The boundary is defined by a global extinction event that caused the abrupt demise of the majority of all life on Earth.

CRUST   :   

The outermost rock layer, divided into continental and oceanic crust. The continental crust is 25-90 km thick and is mostly granite and andesite. The oceanic crust is 6-11 km thick and mostly basalt.

CRYOBIOLOGY   :   

The branch of science that deals with the study of life under low temperature conditions. The word is derived from a Greek word cryo that means cold, bios that means 'life' and logos meaning 'science'.

CRYSTALLINE   :   

Rock types made up of crystals or crystal fragments, such as metamorphic rocks that recrystallized in high temperature or pressure environments, or igneous rocks that formed from cooling of a melt.

CYANOBACTERIA   :   

A phylum of Bacteria that obtain their energy through photosynthesis. They are often referred to as blue-green algae, although they are in fact prokaryotes, not algae.

CYBERSPACE   :   

The term is used to describe the wide range of informational resources that are available through computer networks. This term was originally coined by author William Gibson in his novel Neuromancer.

CYCLIC REDUNDANCY CHECKSUM (CRC)   :   

A redundancy check by a cyclic algorithm generating a check key. The sending and receiving stations are checked after a block check character is accumulated.

CYTOLOGY   :   

The branch of science under life science that deals with the study of cell structure, function and chemistry is called as cytology.