perennially frozen rocks

См. также в других словарях:

• permafrost — /perr meuh frawst , frost /, n. (in arctic or subarctic regions) perennially frozen subsoil. Also called pergelisol. [1943; PERMA(NENT) + FROST] * * * Perennially frozen earth, with a temperature below 32 °F (0 °C) continuously for two years or… …   Universalium

• Snowball Earth — The Snowball Earth hypothesis as it was originally proposedcite book author = Kirschvink, J.L. year = 1992 chapter = Late Proterozoic low latitude global glaciation: The snowball Earth title = The Proterozoic Biosphere: A Multidisciplinary Study… …   Wikipedia

• glacial landform — ▪ geology Introduction  any product of flowing ice and meltwater. Such landforms are being produced today in glaciated areas, such as Greenland, Antarctica, and many of the world s higher mountain ranges. In addition, large expansions of present… …   Universalium

• river — river1 riverless, adj. riverlike, adj. /riv euhr/, n. 1. a natural stream of water of fairly large size flowing in a definite course or channel or series of diverging and converging channels. 2. a similar stream of something other than water: a… …   Universalium

• mass movement — an organized effort by a large number of people, esp. those not forming part of the elite of a given society, to bring about pervasive changes in existing social, economic, or political institutions, frequently characterized by charismatic… …   Universalium

• Pleistocene Epoch — Earlier and longer of the two epochs that constitute the Quaternary Period. The Pleistocene began с 1.8 million years ago and ended с 10,000 years ago. It was preceded by the Pliocene Epoch of the Tertiary Period and followed by the Holocene… …   Universalium

• ice formation — Any mass of ice that occurs on the Earth s continents or surface waters. Such masses form wherever substantial amounts of liquid water freeze and remain in the solid state for some period of time. Examples include glaciers, icebergs, sea ice, and …   Universalium

• United States — a republic in the N Western Hemisphere comprising 48 conterminous states, the District of Columbia, and Alaska in North America, and Hawaii in the N Pacific. 267,954,767; conterminous United States, 3,022,387 sq. mi. (7,827,982 sq. km); with… …   Universalium

• Asia — /ay zheuh, ay sheuh/, n. a continent bounded by Europe and the Arctic, Pacific, and Indian oceans. 2,896,700,000; ab. 16,000,000 sq. mi. (41,440,000 sq. km). * * * I Largest continent on Earth. It is bounded by the Arctic Ocean, the Pacific Ocean …   Universalium

• North America — North American. the northern continent of the Western Hemisphere, extending from Central America to the Arctic Ocean. Highest point, Mt. McKinley, 20,300 ft. (6187 m); lowest, Death Valley, 276 ft. (84 m) below sea level. 400,000,000 including… …   Universalium

• performing arts — arts or skills that require public performance, as acting, singing, or dancing. [1945 50] * * * ▪ 2009 Introduction Music Classical.       The last vestiges of the Cold War seemed to thaw for a moment on Feb. 26, 2008, when the unfamiliar strains …   Universalium