rift valley

American  

noun

Geology.

1. graben.

2. a subsea chasm extending along the crest of a mid-ocean ridge, locus of the magma upwellings that accompany seafloor spreading.

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rift valley British  

noun

1. 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

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rift valley Scientific  

1. 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.

2. See more at normal fault

3. 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.

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Etymology

Origin of rift valley

First recorded in 1890–95

Example Sentences

The polar environment at that time was a rift valley with braided rivers.

From Science Daily • Nov. 16, 2023

One of Iceland’s most popular tourist destinations, the park lies in a rift valley that marks the crest of the Mid-Atlantic Ridge and the boundary between the North American and Eurasian tectonic plates.

From Washington Post • Oct. 14, 2021

Surrounded by glaciers and rocky peaks, I stared south down the Albertine rift valley to Lake George and west into DRC.

From The Guardian • Jan. 8, 2018

The lake occupies a broad rift valley where Earth's crust has thinned, and radar surveys by Blankenship show putative volcanoes under the ice3, 4.

From Nature • Aug. 19, 2014

There are great mesas here, twice as high as the Tibetan plateau, an immense rift valley, possibly giant volcanoes and a mountain as high as Everest.

From "Cosmos" by Carl Sagan