a subsea chasm extending along the crest of a mid-ocean ridge, locus of the magma upwellings that accompany seafloor spreading.
a long narrow valley resulting from the subsidence of land between two parallel faults, often associated with volcanism. The East African Rift Valley is an example
A long, narrow valley lying between two normal geologic faults. Rift valleys usually form where the Earth’s lithosphere has become thin through extension associated with plate-tectonic processes. Unlike river valleys and glacial valleys that form primarily through erosional processes, rift valleys form by the subsidence of the intermediate land as the faults are pulled apart. They are on the order of thousands of kilometers long and wide. See more at normal fault.
The deep undersea valley located along the center of the mid-ocean ridge. It is associated with the crustal thinning and extensional forces that cause magma to upwell onto the ocean floor.
[rift] /rɪft/ noun, Pathology. 1. a highly infectious viral disease of humans and animals, transmitted by mosquitoes and other insects, occurring in Africa and characterized in humans by headache, fever, eye discomfort, and muscle aches, progressing in some cases to encephalitis, blindness, or internal bleeding.
noun, Geology. 1. a system of related, narrow structural depressions between parallel faults.
noun 1. a seaport in and the capital of Latvia, on the Gulf of Riga. 2. Gulf of, an arm of the Baltic between Latvia and Estonia. 90 miles (145 km) long. noun 1. a republic in N Europe, on the Baltic, S of Estonia, an independent state 1918–40; annexed by the Soviet Union 1940; […]
noun 1. a lively dance, formerly popular, for one couple, characterized by a jumping step and usually in quick duple meter. 2. a piece of music for this dance or in its rhythm. noun 1. an old Provençal couple dance, light and graceful, in lively duple time 2. a piece of music for or in […]