Glossary E

Easterly Wave
A wavelike disturbance in the tropical easterly winds that usually moves from east to west. Such waves can grow into tropical depressions.

Ebb (ocean)
Tidal currents that are moving away from the beach

Echolocation
Measuring distances from objects by sound.

Ecosystem
A community of organisms interacting with one another and with the environment in which they live.

Elaiosome
A nutrient parcel attached to a seed which insects eat.

Elevation
The height of a point on the Earth's surface above sea level.

Emergent Coastline
A shoreline resulting from a rise in land surface elevation relative to sea level.

Entrails
The internal organs, especially the intestines; viscera.

Equator
An imaginary circle around the earth, halfway between the north and south poles; the largest circumference of the Earth.

Erosion
The process in which a material is worn away by a stream of liquid (water) or air.

Erratic
A boulder that has been carried from its source by a glacier and deposited as the glacier melted. Thus, the boulder is often of a different rock type from surrounding types.

Escarpment
A long cliff or steep slope separating two comparatively level or more gently sloping surfaces and resulting from erosion or faulting.

Estuary
An estuary is where a river meets the sea or ocean,where it empties into a large body of water.

Evaporates
The change in form that water goes through when it turns from a liquid to a gas.

Evapotranspiration
The water lost from an area through the combined effects of evaporation from the ground surface and transpiration from the vegetation.