Volcanic lava rock that is thick and porous and has a rough, jagged surface when it cools. It is a Hawaiian word, pronounced ah‐ah.
Any well that has not been used for a long time and/or is not properly sealed, and is so poorly maintained that it cannot be used for the purpose for which it was intended.
Waste materials produced by remediation activities.
The zone of a glacier in which losses through various processes, such as calving, deflation, melting, etc., exceed any addition through snowfall or accumulation of rime ice. Compare accumulation zone.
A chronology that determines the age of a feature or event in years. Contrast relative chronology.
The amount of water vapour in air, determined as the mass of vapour per unit mass of air, and normally given in grams per cubic metre. See also humidity; specific humidity.
An extreme state of poverty, in which the standard of living is below the minimum that is needed for the maintenance of life and health. Contrast relative poverty.
The maximum elevation of a particular area above sea level. Contrast relative relief.
A condition that exists when there is not enough of a resource in existence to satisfy existing demand for it. Contrast relative scarcity.
To take something in (such as the penetration of a solid substance by a liquid, by capillary, osmotic, solvent, or chemical action). In energy terms, to take in energy and then not reflect it.