Erosion, Escarpment, Estuary, Eulittoral, Eustacy: Word Origins, Descriptions of Coastal Features, Processes

In the current alphabetic series of word origins and physical descriptions of coastal features and processes, here are erosion, escarpment, estuary, eulittoral, and eustacy.

Erosion
The English word erosion is borrowed from Middle French erosion, from Latin erosion-, a combining form of erosio, from erosus, the past participle of erodere ("to erode," literally "to eat away"), a combination of e- ("away") and rodere ("to gnaw").

Erosion is the process of wearing away land by natural forces. On a coast, the process involves the breaking down and carrying away of beach material by the actions of waves, tidal currents, and wind.

Wave erosion results mainly from the direct impact of waves hitting the shore and from the abrasive action of sand and pebbles churned by the waves.

Wind not only carries away loose material but also creates such material by blowing sand against, and thus breaking down, rock.

Escarpment
The English word escarpment comes from French escarpement, from escarper ("to scarp, cut down vertically"), from Middle French escarper, from escarpe ("scarp"), from Old Italian scarpa ("scarp"), which is probably of Germanic origin. The word is akin to Old English scearp ("sharp").

The original meaning of escarpment is a steep slope cut out in front of a fortification. On a coast, an escarpment is a line of steep cliffs formed by erosion or faulting.

The older word scarp also denotes the same two senses, original and coastal.

Estuary
The English word estuary comes from Latin aestuarium, from aestus ("boiling, tide"). The word is akin to Latin aestas ("summer").

An estuary is a partly enclosed coastal body of water where saltwater mixes with freshwater. The term especially applies to an arm of the sea where the tide meets a river current near the mouth of the river.

Many coastal bodies of water known by other names are technically estuaries, such as Chesapeake Bay.

Eulittoral
The noun eulittoral is formed from the Latin and Greek prefix eu- ("well, true, most typical, improved") and the noun littoral ("coastal region"), from the adjective littoral ("of a seashore"), from Latin litoralis, from litor-, a combining form of litus ("seashore").

Eulittoral denotes a landward subdivision of the littoral zone (coastal region), usually starting at a water depth of less than 50 meters.

Eustacy
Eustacy is a modern International Scientific Vocabulary word built from the Latin and Greek prefix eu- ("well, true, most typical, improved") and -stacy, an irregular form constructed from Greek stasis ("condition of standing still").

Eustacy denotes a worldwide change of sea level. The idea is usually conveyed as an adjective, eustatic ("relating to, or characterized by, a worldwide change of sea level").
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Encyclopaedia Britannica Ready Reference 2004. CD-ROM. Encyclopaedia Britannica, 2004.

Merriam-Webster's Collegiate Dictionary. 11th ed. Springfield, Mass.: Merriam-Webster, 2006.

Merriam-Webster's Geographical Dictionary. 3rd ed. Springfield, Mass.: Merriam-Webster, 2007.

The Oxford English Dictionary. 2nd ed. Oxford, England: Clarendon Press, 1989.