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varve

(Encyclopedia)varve, in geology, pair of thin sedimentary layers formed annually by seasonal climatic changes. Usually found in glacial lake deposits, varves consist of a coarse-grained, light-colored summer deposi...

tunicate

(Encyclopedia)tunicate to͞oˈnəkĭt [key], marine animal of the phylum Chordata, which also includes the vertebrates. The adult form of most tunicates (also called urochordates) shows no resemblance to vertebrate...

sea star

(Encyclopedia)sea star, also called starfish, echinoderm of the class Asteroidae, common in tide pools. Sea stars vary in size from under 1⁄2 in. (1.3 cm) to over 3 ft (90 cm) in diameter. They are commonly dull ...

carbon dioxide

(Encyclopedia)carbon dioxide, chemical compound, CO2, a colorless, odorless, tasteless gas that is about one and one-half times as dense as air under ordinary conditions of temperature and pressure. It does not bur...

Earth Day

(Encyclopedia)Earth Day, Apr. 22, a day to celebrate the environment. The first Earth Day was organized in 1970 to promote the ideas of ecology, encourage respect for life on earth, and highlight growing concern ov...

Eder

(Encyclopedia)Eder āˈdər [key], river, c.110 mi (180 km) long, rising near Siegen, central Germany, and flowing E to the Fulda River. The Eder dam, at Hemfurth, impounds one of the largest reservoirs in Germany;...

Anu

(Encyclopedia)Anu āˈno͞o [key], ancient sky god of Sumerian origin, worshiped in Babylonian religion. The son of Apsu (the underworld ocean) and Tiamat (primeval chaos), Anu was king of the great triad of gods, ...

hydria

(Encyclopedia)hydria hīˈdrēə [key], ancient Greek water jar with three handles—two lateral for lifting, a third vertical for pouring. In shape it was similar to the amphora, the early form having a narrower s...

Anáhuac

(Encyclopedia)Anáhuac änäˈwäk [key] [Aztec and Nahuatl,=near the water], geographical term used variously in Mexico before the Spanish Conquest. Today it commonly refers to that part of the central plateau of ...

Montrose

(Encyclopedia)Montrose, town (1991 pop. 12,127), Angus, NE Scotland, on the North Sea at the mouth of the South Esk River. Open to water on three sides, it is a spacious resort town, with flax and jute mills, boat ...