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Precambrian

(Encyclopedia)Precambrian, name of a major division of geologic time (see Geologic Timescale, tablegeologic timescale, table), from c.5 billion to 570 million years ago. It is now usually divided into the Archean a...

radar

(Encyclopedia)radar, system or technique for detecting the position, movement, and nature of a remote object by means of radio waves reflected from its surface. Although most radar units use microwave frequencies, ...

Denmark

(Encyclopedia)CE5 Denmark dĕnˈmärk [key], Dan. Danmark, officially Kingdom of Denmark, kingdom (2015 est. pop. 5,689,000), 16,629 sq mi (43,069 sq km), N Europe. It borders on Germany in the south, the North ...

Svalbard

(Encyclopedia)Svalbard svälˈbärd [key], archipelago (23,958 sq mi/62,051 sq km), island group (2015 est. pop. 2,700), possession of Norway, located in the Arctic Ocean, c.400 mi (640 km) N of the Norwegian mainl...

meteorite

(Encyclopedia)meteorite, meteor that survives the intense heat of atmospheric friction and reaches the earth's surface. Because of the destructive effects of this friction, only the very largest meteors become mete...

mummy

(Encyclopedia)mummy, dead human or animal body preserved by embalming or by unusual natural conditions. As a rule mummies are from ancient times. The word is of Arabic derivation and refers primarily to the burials...

glacier

(Encyclopedia)glacier, moving mass of ice that survives year to year, formed by the compacting of snow into névé and then into granular ice and set in motion outward and downward by the force of gravity and the s...

map projection

(Encyclopedia)map projection, transfer of the features of the surface of the earth or another spherical body onto a flat sheet of paper. Only a globe can represent accurately the shape, orientation, and relative ar...

exploration

(Encyclopedia)exploration, travel to a part of the earth that is relatively unknown to the traveler's culture, historically often motivated by a desire for colonization, conquest, or trade. See also space explorati...

Pleistocene epoch

(Encyclopedia)Pleistocene epoch plīˈstəsēn [key], 6th epoch of the Cenozoic era of geologic time (see Geologic Timescale, tablegeologic timescale, table). According to a classification that considered its depos...