Glossary Database

Select a Letter to view the associated terms.
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

 Glossary Term: 

Definition:
 Wash  A dry stream bed.
 Water gap  A pass in a ridge through which a stream flows.
 Water table  The upper surface of the zone of saturation beneath the surface. See also: aquifer.
 Watershed  A term used for a drainage divide.
 Wave base  The lower limit of wave transportation and erosion, equal to half the wavelength.
 Wave crest  The highest part of a wave.
 Wave height  The vertical distance between a wave crest and the preceding trough.
 Wave period  The interval of time required for a wave crest to travel a distance equal to one wavelength; the interval of time required for two successive wave crests to pass a fixed point.
 Wave refraction  The process by which a wave is bent or turned from its original direction. In sea waves, as a wave approaches a shore obliquely, part of it reaches the shallow water near the shore while the rest is still advancing in deeper water; the part of the wave in the shallower water moves more slowly than the part in the deeper water. In seismic waves, refraction results from the wave encountering material with a different density or composition.
 Wave trough  The lowest part of a wave, between successive crests.
 Wave-built terrace  A terrace built up from wave-washed sediments. Wave-built terraces usually lie seaward of a wave-cut terrace.
 Wave-cut cliff  A cliff formed along a coast by the undercutting action of waves and currents.
 Wave-cut platform  A terrace cut across bedrock by wave erosion. Synonymous with wave-cut terrace.
 Wave-cut terrace  See wave-cut platform.
 Wavelength  The horizontal distance between similar points on two successive waves, measured perpendicular to the crest.
 Wean  to accustom a child or young animal to food other than the mother's milk (Morris 1992).
 Weather  A physical state of the atmosphere at a given time and place.
 Weathering  The processes by which rocks are chemically altered or physically broken into fragments as a result of exposure to atmospheric agents and the pressures and temperatures at or near Earth's surface, with little or no transportation of the loosened or altered materials.
 Welded tuff  A rock formed from particles of volcanic ash that were hot enough to become fused together.
 Wild Trout  A management program which relies on the natural production potential of a stream to provide fishing opportunity for wild trout. Applied to streams with good to excellent trout habitat where consumptive fishing pressure is light to moderate.
 Wind gap  A gap in a ridge through which a stream, now abandoned as a result of stream piracy, once flowed.
 Wind shadow  The area behind an obstacle where air movement is not capable of moving material.
 Wrinkle ridge  A sinuous, irregular segmented ridge on the surface of a lunar mare, believed to be a result of compression of the lava.