Glossary Z

Zebroid
A hybrid animal that results from breeding zebras and horses.

Zonal
Movement of wind or ocean waters in a direction that is roughly parallel to the lines of latitude.

Zooplankton
The floating creatures ranging from microscopic diatoms to small fish and shrimp.

Zooxanthellae
A form of algae that lives symbiotically in the tissue of corals and other animals and provides some of the coral's food supply by photosynthesis.

Zonal Wind
Atmospheric wind component which flows along the latitude.

Zone of Ablation
Area of a glacier where losses of ice from melting, evaporation, and sublimation exceed additions of snow annually.

Zone of Accumulation
Area of a glacier where additions of snow exceed losses of ice frommelting, evaporation, andsublimation.

Zone of Aeration
Horizontal zone that extends from the top of the water table to the ground surface. Soil and rock pore spaces in this zone may and may not have water.

Zone of Saturation
Groundwater zone within the Earth's bedrock where all available pores spaces are filled by water. Found beneath the water table.