accretionary wedge Quick reference
A tectonically thickened wedge of *sediment found on the landward side of some *trenches. The accretionary wedge consists of oceanic sediment scraped off the subducting ...
acid rain Quick reference
A form of *air pollution created by acid-forming reactions within the atmosphere involving gaseous pollutants, principally *sulphur dioxide
Adams–Williamson equation Quick reference
Equation describing a fundamental relationship between seismic velocities (v p and v ω), the *gravitational acceleration (...
adiabat Quick reference
A line plotted on a thermodynamic diagram, usually on a *tephigram, showing as a continuous sequence the temperature and pressure states of a parcel of air with changing height. An ...
Affective Imagery, Risk Perceptions, and Climate Change Communication Reference library
Anthony Leiserowitz and Nicholas Smith
Natural scientists have described global warming as perhaps the preeminent environmental risk confronting the world in the 21st century
age and early evolution of the Earth and Solar System Reference library
One of the questions that geologists are most frequently asked is ‘How do you know the age of the rocks?’
age–sex pyramid Quick reference
A set of two histograms set back to back on a vertical axis, depicting the numbers of the two sexes by age group. In many less developed countries the pyramid will have a very wide base; these are termed ...
Social scientists and media critics have often been befuddled about how and why news coverage of important issues takes
Airy model Quick reference
A model to account for *isostasy which in the *lithosphere assumes a constant density (ρc = 2 670 kg/m...
aklé Quick reference
French term for a network of sand *dunes found especially in the western Sahara. The basic unit of the network is a sinuous ridge, at right angles to the wind, made up of crescent-shaped sections which alternately face the wind (linguoid) and back to the wind (barchanoid). Aklé patterns require winds from one direction, and a large quantity of sand....
ambulacrum Quick reference
In *Echinodermata, an area of the body surface (covered in most classes by calcitic (see
Anapsida Quick reference
Group of *reptiles characterized by a skull that lacks apertures in the temple regions behind the eyes. This was the condition in the earliest reptiles, the ...