ablation zone
Overview page. Subjects: Environmental Science — Meteorology and Climatology.
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...
absolute humidity
Overview page. Subjects: Environmental Science — Earth Sciences and Geography.
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.
abyssal hill
Overview page. Subjects: Environmental Science — Earth Sciences and Geography.
Relatively small topographic features of a dominantly flat, deep-ocean floor, commonly 50–250 m in height and a few kilometres in width. They are most typical of the Pacific Ocean floor at...
abyssal zone
Overview page. Subjects: Environmental Science — Earth Sciences and Geography.
The lower depths of the ocean (below approximately 2000 metres), where there is effectively no light penetration. Abyssal organisms are adapted for living under high pressures in cold dark...
accretion
Overview page. Subjects: Environmental Science — Earth Sciences and Geography.
accumulation zone
Overview page. Subjects: Environmental Science — Earth Sciences and Geography.
The zone of a glacier in which the amount of snow and ice that is deposited exceeds that lost by deflation, evaporation, melting, or other means. Compare ablation zone.
active fault
Overview page. Subjects: Environmental Science — Earth Sciences and Geography.
A geological fault that is still active rather than dormant, meaning that significant displacement or movement has occurred on it within about the last 10 000 years.
aeration zone
Overview page. Subjects: Environmental Science — Earth Sciences and Geography.
The subsurface zone between the ground surface and the water table, where the pores in soil and rock contain both air and water. Also known as unsaturated zone, vadose zone, or zone of...
agent
Overview page. Subjects: Environmental Science — Earth Sciences and Geography.
Any physical, chemical, or biological entity that can affect (benefit or injure) an organism, people, or the environment. Also known as an environmental agent or stressor.
agrarian
Overview page. Subjects: Environmental Science — Earth Sciences and Geography.
Describing an agricultural system which combines horticulture and animals.